# Patent

## Title
Therapeutic compounds

## Abstract

The invention provides compounds and compositions that are useful for treating conditions including Alzheimer's disease, Parkinson's disease, diabetes, cancer, and psychotic disorders such as schizophrenia.

## Background
RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/945,020, filed Feb. 26, 2014.


GOVERNMENT FUNDING
This invention was made with government support under R15 CA139364 awarded by the National Institutes of Health. The government has certain rights in the invention.


BACKGROUND OF THE INVENTION
The human retinoid X receptors (hRXRs) consist of three identified isoforms (α, β, γ) that function as transcription promoters often in partnership with other members of a larger nuclear receptor (NR) family of transcription regulators including the thyroid receptor (TR), the vitamin D receptor (VDR), the liver X receptor (LXR), the peroxisome proliferator-activated receptor (PPAR), and the retinoic acid receptor (RAR). While 9-cis-retinoic acid (9-cis-RA) and docosahexaenoic acid (DHA) have been shown to bind to hRXRs and promote RXR element (RXRE) regulated transcription (i.e. function as RXR agonists), it is still unclear if RXR has a bona fide endogenous molecular ligand. RXR has been described as the central NR regulator, because it often plays a critical role, either as a permissive or non-permissive partner, in heterodimer complexes that must be formed with the other NRs to regulate their respective response elements.
Recent studies have identified several RXR-selective-binding molecular ligands (rexinoids) that can modulate not only RXRE regulated transcription but also the heterodimer regulated transcription of other NRs. For instance, RXR is a subordinate partner in the RXR-RAR heterodimer, otherwise referred to as a non-permissive heterodimer, since transcription is not promoted in the RAR unliganded (apo-RAR) heterodimer with RXR. Additionally, the RXR-TR heterodimer is non-permissive. In contrast to these non-permissive heterodimers, permissive heterodimers such as RXR-PPAR allow transcription to be promoted in the presence of either RXR or PPAR agonists. The RXR-LXR heterodimer is also permissive. Hence, there is enormous potential for RXR agonists to activate or repress various biological pathways and effect therapeutic results for various conditions that would benefit from activation or repression of a specific pathway.
Bexarotene has been used to treat cutaneous T cell lymphoma. Bexarotene has also been shown to be useful for treatment of Alzheimer's Disease (AD). However, bexarotene treatment results in untoward side effects, possibly due to its nonspecific nature of binding RXR in several states, including the RXR-RXR homodimer form as well as RXR heterodimer forms.
McFarland, K., et al, ACS Chem. Neurosci., 2013, 4(11), 1430-1438 treated a rat model of Parkinson's disease (PD) with bexarotene and noted marked improvement in the PD symptoms. Specifically the bexarotene restored dopamine cells and natural behavior in the PD model. As importantly, the bexarotene dose that accomplished this was quite low, alleviating some side effects. The researchers demonstrated that these symptoms were alleviated by bexarotene binding to RXR and its heterodimerizing with another nuclear recpetor called Nurr1.
PD is a chronic, debilitating disorder in which the neurons of the central nervous system degenerate over time. Specifically the dopamine secreting cells of the midbrain slowy die off, leaving the patient with a wide range of symptoms due to the lack of dopamine. Early symptoms include shaking, off balance gait, and slowless of muscles. Over time, symptoms worsen and additional symptoms including demetia and/or depression can develop. Treatments include dopamine agonists, given to try to ameliorate the effect of loss of dopamine in the system.
Currently there is a need for additional chemical agents that are useful for treating conditions including Alzheimer's disease, Parkinson's disease, diabetes, cancer, and psychotic disorders such as schizophrenia.
SUMMARY OF THE INVENTION
The present invention provides compounds that are useful for treating conditions including Alzheimer's disease, Parkinson's disease, diabetes, cancer, and psychotic disorders such as schizophrenia.
Accordingly, one embodiment provides a compound of the invention which is compound selected from formulae I-X:




wherein:

R1 is a nine-membered bicyclic heteroaryl ring that is substituted with one or more carboxy and that is optionally substituted with one or more groups independently selected from halo, hydroxy, cyano, nitro, (C1-C6)alkyl, (C3-C6)cycloalkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, (C1-C6)alkoxycarbonyl, and (C1-C6)alkanoyloxy, wherein each (C1-C6)alkyl, (C3-C6)cycloalkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, (C1-C6)alkoxycarbonyl, and (C1-C6)alkanoyloxy, is optionally substituted with one or more groups independently selected from halo, hydroxy, nitro, cyano, (C1-C6)alkoxy, and oxo (═O);




wherein:

X is N, Y is CH and Z is N;
X is N, Y is CH and Z is CH;
X is N, Y is N and Z is CH;
X is CH, Y is CH and Z is CH;
R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br; wherein the ring containing X, Y, and Z is optionally substituted on carbon with one or more groups independently selected from halo;




wherein:

Xa is CH, Ya is CH and Za is CH;
Xa is CH, Ya is CH and Za is N;
Xa is N, Ya is N and Za is CH; and
R4 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br; wherein the ring containing Xa, Ya, and Za is optionally substituted on carbon with one or more groups independently selected from halo;




wherein:

R5 is ethyl, propyl, or isopropyl;




wherein:

R10 is H or methyl;
and salts thereof;
provided the compound is not:




Another embodiment provides a compound of the invention which is a compound of formula (XI):




or a salt thereof.

Another embodiment provides a compound of the invention which is a compound of formula (XII):




or a salt thereof.

The invention also provides a pharmaceutical composition comprising a compound of formulae I-XII, or a pharmaceutically acceptable salt thereof, in combination with a pharmaceutically acceptable diluent or carrier.
The invention also provides a method for treating Alzheimer's disease, Parkinson's disease, diabetes, cancer, or a psychotic disorder in an animal (e.g. a mammal such as a human) comprising administering a compound of formulae I-XII, or a pharmaceutically acceptable salt thereof, to the animal.
The invention also provides a compound of formulae I-XII, or a pharmaceutically acceptable salt thereof, for the prophylactic or therapeutic treatment of Alzheimer's disease, Parkinson's disease, diabetes, cancer, or a psychotic disorder.
The invention also provides the use of a compound of formulae I-XII, or a pharmaceutically acceptable salt thereof, to prepare a medicament useful for treating Alzheimer's disease, Parkinson's disease, diabetes, cancer, or a psychotic disorder in an animal.
The invention also provides a method for activating RXR in a cell comprising contacting the cell in vitro or in vivo with an effective amount of a compound of formulae I-XII, or a salt thereof.
The invention also provides a compound of formulae I-XII, or a pharmaceutically acceptable salt thereof, for use in medical therapy.
The invention also provides processes and novel intermediates that are useful for preparing a compound of formulae I-XII, or a salt thereof.



BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 Illustrates representative compounds of the invention
FIG. 2 Shows results from Test B for representative compounds of the invention. Analog dependent, RXR-mediated transcription, as measured by luciferase output, was compared to the parent compound Bexarotene (Bex) as a percentage.
FIG. 3 Shows results from Test C for representative compounds of the invention. Analog dependent, RXR-mediated transcription, as measured by luciferase output, was compared to the parent compound Bexarotene (Bex) as a percentage.



DETAILED DESCRIPTION
The term “activating”, such as used in the phrase “activating RXR”, means to promote transcriptional activity.
The term “treatment” or “treating,” to the extent it relates to a disease or condition includes preventing the disease or condition from occurring, inhibiting the disease or condition, eliminating the disease or condition, and/or relieving one or more symptoms of the disease or condition.
The term “6-membered heteroaryl ring” includes rings with at least two carbon atoms and 1, 2, 3, or 4 heteroatoms (e.g. N, O, or S).
Specifically, (C1-C6)alkyl can be methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, pentyl, 3-pentyl, or hexyl; (C3-C6)cycloalkyl can be cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl; (C3-C6)cycloalkyl(C1-C6)alkyl can be cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, 2-cyclopropylethyl, 2-cyclobutylethyl, 2-cyclopentylethyl, or 2-cyclohexylethyl; (C1-C6)alkoxy can be methoxy, ethoxy, propoxy, isopropoxy, butoxy, iso-butoxy, sec-butoxy, pentoxy, 3-pentoxy, or hexyloxy; (C2-C6)alkenyl can be vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl; (C2-C6)alkynyl can be ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, or 5-hexynyl; (C1-C6)alkanoyl can be acetyl, propanoyl or butanoyl; (C1-C6)alkoxycarbonyl can be methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, or hexyloxycarbonyl; (C1-C6)alkanoyloxy can be formyloxy, acetoxy, propanoyloxy, butanoyloxy, isobutanoyloxy, pentanoyloxy, or hexanoyloxy; aryl can be phenyl, indenyl, or naphthyl; and heteroaryl can be pyrazinyl, pyridazine, triazine, pyridyl, or pyrimidinyl, or an N-oxide thereof.
In one specific embodiment the compound of the invention is a compound of formulae Ia, Ib, or Ic:




wherein:

Xb is S, O, or NH;
or a salt thereof.
In one specific embodiment the compound of the invention is a compound of formulae IIa, IIb, or IIc:




wherein:

R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;
or a salt thereof.
In one specific embodiment the compound of the invention is a compound of formulae IIIa, IIIb, or IIIc:




wherein:

R4 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;
or a salt thereof.
In one specific embodiment the compound of the invention is a compound of formula IV, wherein R5 is ethyl or isopropyl; or a salt thereof.
In one specific embodiment the compound of the invention is selected from:













and salts thereof.

In one specific embodiment the compound of the invention is selected from:




and salts thereof.

In one specific embodiment the compound of the invention is selected from compounds of formulae I-X:




wherein:

R1 is a nine-membered bicyclic heteroaryl ring that is substituted with one or more carboxy and that is optionally substituted with one or more groups independently selected from halo, hydroxy, cyano, nitro, (C1-C6)alkyl, (C3-C6)cycloalkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, (C1-C6)alkoxycarbonyl, and (C1-C6)alkanoyloxy, wherein each (C1-C6)alkyl, (C3-C6)cycloalkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, (C1-C6)alkoxycarbonyl, and (C1-C6)alkanoyloxy, is optionally substituted with one or more groups independently selected from halo, hydroxy, nitro, cyano, (C1-C6)alkoxy, and oxo




wherein:

X is N, Y is C and Z is N;
X is N, Y is C and Z is C;
X is N, Y is N and Z is C;
R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;




wherein:

Xa is C, Ya is C and Za is C;
Xa is C, Ya is C and Za is N;
Xa is N, Ya is N and Za is C; and
R4 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;




wherein:

R5 is ethyl, propyl, or isopropyl; and




wherein:

R10 is H or methyl;
and salts thereof;
provided the compound is not:




In one specific embodiment the compound of the invention is selected from:







and salts thereof.

Diseases and Condition

Compounds of the invention possessing RXR agonist properties are useful for treating Alzheimer's disease. The compounds of the invention may also treat Alzheimer's disease by targeting a combination of RXR:LXR controlled genes (like ApoE), or by binding to amyloid beta oligomers (where cholesterol usually binds) and disrupting calcium channel formation in neurons (Fantini, J. et al. ACS Chem. Neurosci. 2014, DOI: 10.1021/cn400183w).
Compounds of the invention are also useful for treating cancers, including but not limited to, colon, breast, lung, pancreatic, skin, cutaneous T-cell lymphoma, acute promyelocytic leukemia, ovarian, bladder, kidney, head and neck cancers, and Kaposi's sarcoma. See breast cancer: Esteva, F. J. et al. JCO, 2003, 21, 999-1006; advanced non-small lung cancer: (a) Khuri, F. R. et al. JCO, 2001, 19, 2626-2637 and (b) Lamph, W. W. et al. Clin. Cancer Res. 2004, 10, 8656-8664; pancreatic cancer: Liby, K. Cancer Prev. Res. 2010, 3, 1427-1434; and colon cancer: Cesario, R. M. et al. Cancer Letters 2006, 240, 225-233.
Compounds of the invention possessing RXR agonist properties and/or that target the Nurr1 receptor are useful for treating Parkinson's disease (see McFarland, K., et al, ACS Chem. Neurosci., 2013, 4(11), 1430-1438), while compounds of the invention possessing RXR agonist properties and/or PPARg activity may be useful for treating diabetes (see Mukherjee, R. et al. Nature, 1997, 386, 407-410).
The compounds of the invention may also be useful for treating, psychotic disorders such as schizophrenia. Such treatment may also be carried out in combination with other antipsychotic treatments (see Lerner, V. et al. Clin. Neuropharmacol. 2008, 31, 25-33).
In cases where compounds are sufficiently basic or acidic, a salt of a compound of the invention can be useful as an intermediate for isolating or purifying a compound of the invention. Additionally, administration of a compound of the invention as a pharmaceutically acceptable acid or base salt may be appropriate. Examples of pharmaceutically acceptable salts are organic acid addition salts formed with acids which form a physiological acceptable anion, for example, tosylate, methanesulfonate, acetate, citrate, malonate, tartrate, succinate, benzoate, ascorbate, α-ketoglutarate, and α-glycerophosphate. Suitable inorganic salts may also be formed, including hydrochloride, sulfate, nitrate, bicarbonate, and carbonate salts.
Pharmaceutically acceptable salts may be obtained using standard procedures well known in the art, for example by reacting a sufficiently basic compound such as an amine with a suitable acid affording a physiologically acceptable anion. Alkali metal (for example, sodium, potassium or lithium) or alkaline earth metal (for example calcium) salts of carboxylic acids can also be made.
The compounds can be formulated as pharmaceutical compositions and administered to a mammalian host, such as a human patient in a variety of forms adapted to the chosen route of administration, i.e., orally or parenterally, by intravenous, intramuscular, topical or subcutaneous routes.
Thus, the compounds may be systemically administered, e.g., orally, in combination with a pharmaceutically acceptable vehicle such as an inert diluent or an assimilable edible carrier. They may be enclosed in hard or soft shell gelatin capsules, may be compressed into tablets, or may be incorporated directly with the food of the patient's diet. For oral therapeutic administration, the active compound may be combined with one or more excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contain at least 0.1% of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 2 to about 60% of the weight of a given unit dosage form. The amount of active compound in such therapeutically useful compositions is such that an effective dosage level will be obtained.
The tablets, troches, pills, capsules, and the like may also contain the following: binders such as gum tragacanth, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, fructose, lactose or aspartame or a flavoring agent such as peppermint, oil of wintergreen, or cherry flavoring may be added. When the unit dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be present as coatings or to otherwise modify the physical form of the solid unit dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac or sugar and the like. A syrup or elixir may contain the active compound, sucrose or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring such as cherry or orange flavor. Of course, any material used in preparing any unit dosage form should be pharmaceutically acceptable and substantially non-toxic in the amounts employed. In addition, the active compound may be incorporated into sustained-release preparations and devices.
The active compound may also be administered intravenously or intraperitoneally by infusion or injection. Solutions of the active compound or its salts can be prepared in water, optionally mixed with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, triacetin, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.
The pharmaceutical dosage forms suitable for injection or infusion can include sterile aqueous solutions or dispersions or sterile powders comprising the active ingredient which are adapted for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions, optionally encapsulated in liposomes. In all cases, the ultimate dosage form should be sterile, fluid and stable under the conditions of manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid dispersion medium comprising, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the formation of liposomes, by the maintenance of the required particle size in the case of dispersions or by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, buffers or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.
Sterile injectable solutions are prepared by incorporating the active compound in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filter sterilization. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying techniques, which yield a powder of the active ingredient plus any additional desired ingredient present in the previously sterile-filtered solutions.
Useful dosages of the compounds of the invention can be determined by comparing their in vitro activity, and in vivo activity in animal models. Methods for the extrapolation of effective dosages in mice, and other animals, to humans are known to the art; for example, see U.S. Pat. No. 4,938,949. Compounds that are non-toxic and non-mutagenic at typical dose levels will have useful doses. (Mortelmans, K.; Zeiger, E. “The Ames Salmonella/microsome mutagenicity assay.” Mutat. Res. 2000, 455, 29-60.)
The amount of the compound, or an active salt or derivative thereof, required for use in treatment will vary not only with the particular salt selected but also with the route of administration, the nature of the condition being treated and the age and condition of the patient and will be ultimately at the discretion of the attendant physician or clinician.
In general, however, a suitable dose will be in the range of from about 0.5 to about 100 mg/kg, e.g., from about 10 to about 75 mg/kg of body weight per day, such as 3 to about 50 mg per kilogram body weight of the recipient per day, preferably in the range of 6 to 90 mg/kg/day, most preferably in the range of 15 to 60 mg/kg/day. The compound is conveniently formulated in unit dosage form; for example, containing 5 to 1000 mg, conveniently 10 to 750 mg, most conveniently, 50 to 500 mg of active ingredient per unit dosage form. In one embodiment, the invention provides a composition comprising a compound of the invention formulated in such a unit dosage form. In certain embodiments, the dose is about 300 mg/m2/day.
The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations; such as multiple inhalations from an insufflator or by application of a plurality of drops into the eye.
Compounds can also be administered in combination with other therapeutic agents. In certain embodiments, compounds of the invention can be administered in combination with agents that are useful for the treatment of diseases associated with dopamine deficiency. For example, the compounds can be administered (and/or formulated) with clozapine, olanzapine, haloperidol, risperidone, perphenazine, quetiapine, or chlorpromazine.
The ability of a compound of the invention to act as an RXR agonist (e.g. to promote or activate RXR, i.e., promote or activate RXR regulated gene expression) may be determined using pharmacological models which are well known to the art, or using Test A or Test B described below.
Test A.
EC50 values were determined from full dose-response curves ranging from 1×10−9 to 0.3×10−5 M in transfected HCT-116 cells using an RXR mammalian two-hybrid system. HCT-116 cells were plated overnight at 80,000 cells/well in a 24 well plate and maintained as described above. The cells were co-transfected using a human RXR binding domain (BD) vector, a human RXR activation domain (AD) vector, a luciferase reporter gene containing BD-binding sites and renilla control plasmid. Transfection was achieved via 2 μL/well of Express-1N transfection reagent which was allowed to incubate for 24 hours with the cells. Then, the cells were treated with ethanol vehicle (0.1%) or analogs (1.0, 2.5, 5.0, 7.5, 10, 25, 50, 75, 100, 250, 500 nM, 1, 2, 3 μM) and incubated for 24 hours. The amount of rexinoid activity at each concentration was measured using the same luciferase assay described above, and EC50 values were derived from dose-response curves of ligand concentration versus normalized luciferase activity. Data for the following representative compounds is provided in Table 1.

















TABLE 1







Compound
EC50 (nM)



















Bexarotene
23



A42
3.7



A43
21



A44
38



A45
710



A46
305



A47
1,030



A48
20



A49
220



A50
270



A51
1,400










Test B.

RXR Agonist Assay (RXRE-Luciferase Based Assay).

An RXRE-luciferase assay of the compounds shown in FIG. 1 was run at 25 nM in HCT-116 cells. The cell line was transfected with hRXRα, an RXRE luciferase reporter gene, renilla control plasmid, and carrier DNA (pTZ18U). Cells were transfected for 7 hours utilizing a liposome-mediated transfection protocol then exposed to either the ethanol or DMSO vehicle or 25 nM Bexarotene or the indicated analog. After 24 hours the cells were lysed and a luciferase assay was completed. Analog dependent, RXR-mediated transcription, as measured by luciferase output, was compared to the parent compound Bexarotene (Bex) as a percentage. Data is provided in FIG. 2.
Test C.
RXR Agonist Assay (RXRE-Luciferase Based Assay).
Compounds were tested for RXR agonist activity via an RXRE-luciferase based system utilizing human colon cancer cells HCT-116. The cell line was transfected with hRXRα, an RXRE luciferase reporter gene, renilla control plasmid, and carrier DNA (pTZ18U). Cells were transfected for 7 hours utilizing a liposome-mediated transfection protocol then exposed to either the ethanol or DMSO vehicle or 100 nM Bexarotene or the indicated analog. After 24 hours the cells were lysed and a luciferase assay was completed. Analog dependent, RXR-mediated transcription, as measured by luciferase output, was compared to the parent compound Bexarotene (Bex) as a percentage. Data is provided in FIG. 3.
Compounds evaluated in Tests A-C that are not prepared in the Examples below (e.g. compounds A42, A44, A48, and A50) were prepare using known techniques or using techniques similar to those described in the Examples.
The invention will now be illustrated by the following non-limiting Examples.
EXAMPLES
Example 1 Synthesis of 6-fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-1H-benzo[d][1,2,3]triazole-5-carboxylic acid (44) (A51)




a. Methyl 2-fluoro-4-iodobenzoate (2)
A modified procedure of Kakuta and co-workers was followed.2 2-Fluoro-4-iodobenzoic acid (5.35 g, 20.1 mmol) was dissolved in methanol (30 mL, 741 mmol) was added thionyl chloride (2.6 mL, 35.8 mmol), dropwise at 0° C. with stirring. The reaction solution was then refluxed in an oil bath at 85° C. for 1 hr. Excess methanol was removed in vacuo, and benzene (20 mL) was added to the residue and then removed in vacuo. To the residue was added ethyl acetate (150 mL), and the organic layer was washed with saturated NaHCO3 (200 mL) and brine (60 mL) and then dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by column chromatography (150 mL SiO2, ethyl acetate:hexanes 1:48) to give 2 (5.3066 g, 94%) as a white crystalline solid, m.p. 76-78° C.: 1H NMR (400 MHz, CDCl3) δ 7.63 (t, J=8.0, 1H), 7.56 (dd, J=8.4, 1.6, 1H), 7.53 (dd, J=10.0, 1.2, 1H), 3.92 (s, 3H); 13C NMR (100.6 MHz, CDCl3) δ 164.4, 164.3, 162.3, 159.7, 133.5, 133.4, 133.0, 126.5, 126.3, 118.2, 118.1, 99.8, 99.7, 52.5; IR (neat) n 2952, 1700, 1595, 1561 cm−1; LC-FAB-MS (M)+ calcd for C8H6FIO2 279.9397. found 279.9394.
b. methyl 2-fluoro-4-iodo-5-nitrobenzoate (3)
A modified procedure of Kakuta and co-workers was followed.2 To a solution of methyl 2-fluoro-4-iodobenzoate (2) (1.4 g, 5.0 mmol) dissolved in concentrated sulfuric acid (5 mL) was added a solution of concentrated nitric acid (6.0 mL) and concentrated sulfuric acid (9.0 mL) dropwise at 0° C. with stirring. The reaction solution was then stirred at room temperature for 5 h. The reaction solution was poured onto ice (100 mL) and extracted with ethyl acetate. The combined organic layers were washed with saturated NaHCO3 (100 mL) and brine (50 mL) and then dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by column chromatography (150 mL SiO2, 2% ethyl acetate:hexanes to 10% ethyl acetate:hexanes) to give 3 (1.27 g, 78%) as a green crystalline solid, m.p. 84-87° C.: 1H NMR (400 MHz, CDCl3) δ 8.50 (d, J=6.4, 1H), 7.87 (d, J=9.6, 1H), 3.97 (s, 3H); 13C NMR (100.6 MHz, CDCl3) δ 163.1, 162.3, 162.2, 160.4, 148.7, 131.1, 130.8, 129.1, 129.0, 119.4, 119.2, 92.7, 92.6, 53.1; IR (neat) n 2987, 1703, 1602, 1560, 1532, 1440 cm−1; LC-FAB-MS (M)+ calcd for C8H5FINO4 324.9247. found 324.9249.




c. 1,1,4,4,6-pentamethyl-7-nitro-1,2,3,4-tetrahydronaphthalene (5)
The method of Kakuta and co-workers was followed.7 To a solution of 1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene (4) (2.0 g, 9.9 mmol) in acetic anhydride (10 mL) cooled to 0° C. was added concentrated nitric acid (0.80 mL), dropwise. A precipitate quickly formed (2 min.) and the heterogeneous solution was poured onto ice and then extracted with ethyl acetate. The combined organic layers were washed with brine and then dried over sodium sulfate, filtered and concentrated in vacuo to give a crude residue. This residue was dissolved in hot ethyl acetate (4.0 mL) and hexanes (6.0 mL) was added and the solution was cooled in an ice bath and the resulting precipitate was filtered to give 5 (1.23 g, 50%) as a white crystalline solid, m.p. 148-150° C.: 1H NMR (400 MHz, CDCl3) δ 7.96 (s, 1H), 7.21 (s, 1H), 2.56 (s, 3H), 1.69 (s, 4H), 1.29 (s, 12H); 13C NMR (100.6 MHz, CDCl3) δ 151.1, 146.8, 144.3, 130.9, 130.4, 123.1, 34.6, 34.5, 34.5, 34.2, 31.6, 31.5, 20.5; IR (neat) n 2960, 2924, 1515, 1347 cm−1; LC-MS-CI (M+NH4)+ calcd for C15H25N2O2 265.1916. found 265.1927.
d. 3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-2-amine (6)
Compound 6 was synthesized as follows. A 0.05 M solution of 1,1,4,4,6-pentamethyl-7-nitro-1,2,3,4-tetrahydronaphthalene (5) (2.5 g, 10.1 mmol) in ethyl acetate (205 mL) was passed through a 10% Pd/C cartridge at 1.0 mL/minute, twice, in the ThalesNano H-cube® at 70° C. and 2-5 bar pressure. The resulting solution was concentrated in vacuo to give 6 (2.13 g, 97%) as a yellow, crystalline solid, m.p. 76-89° C.: 1H NMR (400 MHz, CDCl3) δ 7.00 (s, 1H), 6.63 (s, 1H), 3.34 (br s, 2H), 2.15 (s, 3H), 1.63 (s, 4H), 1.26 (s, 12H); 13C NMR (100.6 MHz, CDCl3) δ 143.5, 142.0, 135.2, 128.3, 120.5, 112.6, 35.3, 35.2, 33.8, 33.4, 32.0, 31.8, 17.1; IR (neat) n 3404, 3335, 2956, 2925, 1626, 1504 cm−1; LC-MS-CI (M+H)+ calcd for C15H24N 218.1909. found 218.1908.




e. Methyl 2-fluoro-5-nitro-4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (7)
To a solution of 3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-amine (6) (0.83 g, 3.82 mmols) and Methyl 2-fluoro-4-iodo-5-nitrobenzoate (3) (1.28 g, 3.93 mmols) in anhydrous toluene (4.0 mL) was added Cs2CO3 (3.11 g, 9.5 mmols), rac-BINAP (0.18 g, 0.28 mmols), and Pd2(dba)3 (0.17 g, 0.19 mmols). The reaction solution was heated to reflux in an oil bath at 125° C. under a nitrogen atmosphere for 22 h and then filtered. The filtrate was concentrated in vacuo and the crude residue was purified by column chromatography (150 mL SiO2, 2% ethyl acetate:hexanes) to give 7 (0.87 g, 54%) as a yellow crystalline solid, m.p. 166-169° C.: 1H NMR (400 MHz, CDCl3) δ 9.60 (br s, 1H), 8.95 (d, J=7.6, 1H), 7.25 (s, 1H), 7.14 (s, 1H), 6.43 (d, J=13.2, 1H), 3.90 (s, 3H), 2.18 (s, 3H), 1.70 (s, 4H), 1.31 (s, 6H), 1.25 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 167.2, 164.6, 162.9, 162.9, 148.6, 148.4, 145.0, 144.6, 133.3, 133.2, 132.7, 131.3, 129.6, 128.5, 124.5, 107.9, 107.7, 102.2, 101.9, 52.2, 34.9, 34.7, 34.1, 34.0, 31.8, 31.7, 17.4; IR (neat) n 3342, 2968, 1709, 1637, 1565, 1526 cm−1; LC-ES-MS (M)+ calcd for C23H27FN2O4Na 437.1852. found 437.1853.




f. Methyl 5-amino-2-fluoro-4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (8)
A 0.05 M solution of methyl 2-fluoro-5-nitro-4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (7) (1.25 g, 3.02 mmol) in ethyl acetate (65 mL) was passed through a 10% Pd/C cartridge at 1.0 mL/minute, twice, in the ThalesNano H-cube® at 70° C. and 2-5 bar pressure. The resulting solution was concentrated in vacuo to give 8 (1.16 g, 100%) as a yellow, crystalline solid, m.p. 221-225° C.: 1H NMR (400 MHz, CDCl3) δ 7.37 (d, J=7.2, 1H), 7.16 (s, 1H), 7.06 (s, 1H), 6.41 (d, J=12.8, 1H), 5.75 (br s, 1H), 3.87 (s, 3H), 3.28 (br s, 2H), 2.16 (s, 3H), 1.68 (s, 4H), 1.29 (s, 6H), 1.24 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 165.3, 165.2, 159.9, 157.4, 143.9, 142.3, 142.2, 141.5, 135.9, 129.2, 129.0, 129.0, 128.4, 120.9, 120.3, 120.2, 107.3, 107.2, 101.4, 101.1, 51.8, 35.1, 34.9, 34.0, 33.8, 31.9, 31.8, 17.4; IR (neat) v 3410, 3388, 3313, 2943, 1689, 1604, 1526, 1502 cm−1; LC-ES-MS (M+H)+ calcd for C23H29FN2O2Na 407.2111. found 407.2115.
g. Methyl 6-fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-1H-benzo[d][1,2,3]triazole-5-carboxylate (9)
To a solution of methyl 5-amino-2-fluoro-4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (8) (1.14 g, 2.96 mmols) in THF (14.0 mL) was added a solution of concentrated sulfuric acid (7.0 mL) and water (70.0 mL) followed by a solution of NaNO2 (0.294 g, 4.26 mmols) in water (14.0 mL). The reaction solution was stirred at 0° C. for 30 min. and then gently warmed to 55° C. for 15 min. The reaction was extracted with ethyl acetate. The combined organic layers were washed with water and brine and then dried over sodium sulfate, filtered and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 2.5% ethyl acetate:hexanes to 10% ethyl acetate:hexanes) to give 9 (1.12 g, 95%) as a crystalline solid, m.p. 152-154° C.: 1H NMR (400 MHz, CDCl3) δ 8.78 (d, J=6.0, 1H), 7.34 (s, 1H), 7.09 (d, J=9.6, 1H), 3.99 (s, 3H), 2.05 (s, 3H), 1.73 (s, 4H), 1.34 (s, 6H), 1.28 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 164.3, 164.2, 162.5, 160.0, 147.6, 144.4, 141.4, 136.0, 135.9, 131.9, 131.3, 129.8, 125.2, 125.1, 124.5, 117.0, 116.9, 97.5, 97.2, 52.6, 34.8, 34.6, 34.3, 34.2, 31.8, 31.7, 17.3; IR (neat) n 2967, 1709, 1630, 1510 cm−1; LC-ES-MS (M)+ calcd for C23H26FN3O2Na 418.1907. found 418.1901.




h. 6-Fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-1H-benzo[d][1,2,3]triazole-5-carboxylic acid (44)
To a round bottom flask containing methyl 6-fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-1H-benzo[d][1,2,3]triazole-5-carboxylate (9) (0.80 g, 2.0 mmols) in methanol (5.0 mL) was added a solution of KOH (0.39 g, 6.95 mmol) in water (0.58 mL), and the reaction solution was refluxed for 1.5 h. After cooling the solution to room temperature, the addition of 20% HCl (80 mL) effected the precipitation of crude product (0.75 g, 96%), and this crude product was purified by column chromatography (25 mL SiO2, ethyl acetate to 4% methanol:ethyl acetate) to give 44 (0.68 g, 87%) as a crystalline solid, m.p. 190-197° C.: 1H NMR (400 MHz, CDCl3) δ 9.99 (br s, 1H), 8.96 (d, J=6.4, 1H), 7.36 (s, 1H), 7.28 (s, 1H), 7.13 (d, J=9.6, 1H), 2.07 (s, 3H), 1.74 (s, 4H), 1.35 (s, 6H), 1.29 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 168.9, 168.8, 163.0, 160.4, 147.7, 144.5, 141.3, 136.6, 136.5, 131.8, 131.3, 129.8, 126.2, 124.5, 116.0, 115.9, 97.8, 97.5, 34.8, 34.6, 34.3, 34.2, 31.8, 31.7, 17.3; IR (neat) n 2960, 1727, 1708, 1684, 1626, 1491, 1454 cm−1; LC-ES-MS (M−H)− calcd for C22H23FN3O2 380.1774. found 380.20.
Example 2 Synthesis of 6-fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-2-(trifluoromethyl)-1H-benzo[d]imidazole-5-carboxylic acid (49) (A49)




a. Methyl 6-fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-2-(trifluoromethyl)-1H-benzo[d]imidazole-5-carboxylate (10)
To a flask containing methyl 2-fluoro-5-nitro-4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (7) was added TFA (12.0 mL) and trifluoroacetic anhydride (2.4 mL, 16.8 mmol) and stirred for 1 h. TLC showed little progress, so an additional portion of trifluoroacetic anhydride (2.4 mL, 16.8 mmol) was added and the reaction was heated to 57° C. with stirring for 1 h. TLC indicated the reaction had progressed, and an additional portion of trifluoroacetic anhydride (2.0 mL, 14.0 mmol) was added and the reaction was allowed to stir for another 1 h. The reaction was allowed to cool to room temperature and then slowly poured into saturated NaHCO3 (100 mL) and extracted with ethyl acetate. The combined organic layers were washed with water (50 mL) and then brine (50 mL), dried over sodium sulfate, filtered, and concentrate in vacuo to give a crude residue that was purified by column chromatography (150 mL SiO2, 2.6% ethyl acetate:hexanes to 2.8% ethyl acetate:hexanes) to give 10 (Scheme 16) (1.15 g, 83%) as a crystalline solid, m.p. 122-125° C.: 1H NMR (400 MHz, CDCl3) δ 8.54 (d, J=6.4, 1H), 7.28 (s, 1H), 7.17 (s, 1H), 6.80 (d, J=10.0, 1H), 3.96 (s, 3H), 1.88 (s, 3H), 1.72 (s, 4H), 1.33 (s, 6H), 1.24 (s, 3H), 1.23 (s, 3H); 13C NMR (100.6 MHz, CDCl3) δ 164.7, 164.6, 161.6, 159.1, 147.8, 144.6, 143.6, 143.2, 143.2, 139.7, 139.6, 136.3, 132.0, 129.6, 129.3, 126.2, 125.9, 125.9, 119.6, 116.9, 116.1, 116.0, 99.2, 98.9, 52.4, 34.8, 34.6, 34.3, 34.1, 31.8, 31.7, 31.6, 31.6, 16.6; IR (neat) n 2960, 1731, 1632, 1533, 1501 cm−1; LC-ES-MS (M+Na)+ calcd for C25H26F4N2O2Na 485.1828. found 485.1828.
b. 6-Fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-2-(trifluoromethyl)-1H-benzo[d]imidazole-5-carboxylic acid (49)
To a round bottom flask containing methyl 6-fluoro-1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-2-(trifluoromethyl)-1H-benzo[d]imidazole-5-carboxylate (10) (1.02 g, 2.27 mmols) in methanol (5.3 mL) was added a solution of KOH (0.40 g, 7.13 mmol) in water (0.50 mL), and the reaction solution was refluxed for 1.5 h. After cooling the solution to room temperature, the addition of 20% HCl (80 mL) effected the precipitation of crude product, and this crude product was purified by column chromatography (25 mL SiO2, 40% ethyl acetate:hexanes to ethyl acetate) to give 49 (0.62 g, 62%) as a crystalline solid, m.p. 219-220° C.: 1H NMR (400 MHz, CDCl3) δ 9.57 (br s, 1H), 8.71 (d, J=6.4, 1H), 7.30 (s, 1H), 7.19 (s, 1H), 6.85 (d, J=10.0, 1H), 1.91 (s, 3H), 1.73 (s, 4H), 1.34 (s, 6H), 1.25 (s, 3H), 1.24 (s, 3H); 13C NMR (100.6 MHz, CDCl3) δ 169.3, 169.2, 162.2, 159.6, 147.9, 144.7, 144.2, 143.9, 143.8, 143.5, 143.4, 143.1, 140.5, 140.3, 136.3, 132.0, 129.5, 129.4, 126.8, 126.2, 122.3, 119.5, 116.8, 115.1, 115.0, 114.1, 99.4, 99.1, 34.8, 34.6, 34.3, 34.1, 31.8, 31.7, 31.7, 31.6, 16.6; IR (neat) n 2962, 1681, 1629, 1536, 1423 cm−1; LC-ES-MS (M−H)− calcd for C24H23F4N2O2 447.1696. found 447.1709.
Example 3 Synthesis of (E)-3-(4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (69) (A43)
4-Bromopicolinaldehyde (66) was converted to (E)-ethyl 3-(4-bromopyridin-2-yl)acrylate (67) in 96% yield by a Horner-Wadsworth-Emmons reaction (Scheme 7).




The acrylate 67 is then reacted with the boronic acid 82 to give (E)-ethyl 3-(4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylate (68) in 92% yield which is saponified to (E)-3-(4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (69) in 74% yield (Scheme 8).




a. (E)-Ethyl 3-(4-bromopyridin-2-yl)acrylate (67)
To a solution of a 60% dispersion of NaH in mineral oil (0.29 g, 7.25 mmol) in DME (2 mL) at −30° C. was added a solution of ethyl 2-phosphonoacetate (1.46 mL, 7.29 mmol) in DME (13 mL), and the mixture was stirred at this temperature for 30 min. To this solution was added a solution of 4-bromopicolinaldehyde (66) (1.24 g, 6.67 mmol) in DME (3 mL), and the reaction was stirred at −30° C. for 1.5 h and then poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with an aqueous saturated NH4Cl solution and then brine, dried over sodium sulfate, filtered and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes) to give 67 (1.647 g, 96%) as a colorless crystalline solid, m.p. 70-72° C.: 1H NMR (400 MHz, CDCl3) δ 8.43 (d, J=5.2, 1H), 7.58 (d, J=15.6, 1H), 7.57 (d, J=1.6, 1H), 7.42 (dd, J=5.2, 1.6, 1H), 6.91 (d, J=15.6, 1H), 4.26 (q, J=7.2, 2H), 1.32 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 166.2, 154.3, 150.6, 141.7, 133.3, 127.2, 127.1, 123.9, 60.7, 14.2; IR (neat) δ 2987, 1712, 1646, 1563, 1537 cm−1; LC-FAB-MS (M+H)+ calcd for C10H11BrNO2 255.9973. found 255.9963.
b. (E)-Ethyl 3-(4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylate (68)
To a 50 mL Schlenk flask charged with bromide 67 (0.4125 g, 1.61 mmol), boronic acid 82 (0.411 g, 1.67 mmol), TBAB (0.52 g), Na2CO3 (0.51 g, 4.81 mmol), and water (3.7 mL), was added Pd(OAc)2 (0.0203 g, 0.09 mmol), and the flask was evacuated and back-filled with nitrogen three times. The reaction was stirred at room temperature for 15 min and then placed in an oil bath pre-heated to 150° C. and stirred for 5 min. The reaction was allowed to cool to room temperature, and the black residue was taken up in ethyl acetate and water. The layers were separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes) to give 68 (0.56 g, 92%) as a white solid: 1H NMR (400 MHz, CDCl3) δ 8.65 (d, J=5.2, 1H), 7.73 (d, J=16.0, 1H), 7.41 (d, J=0.8, 1H), 7.27 (dd, J=5.2, 1.6, 1H), 7.22, (s, 1H), 7.14 (s, 1H), 6.97 (d, J=16.0, 1H), 4.28 (q, J=6.8, 2H), 2.25 (s, 3H), 1.71 (s, 4H), 1.34 (t, J=7.2, 3H), 1.32 (s, 6H), 1.29 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 166.7, 152.5, 151.2, 149.5, 145.6, 143.1, 143.0, 135.8, 131.8, 128.8, 127.4, 124.9, 124.8, 122.6, 60.6, 34.9, 34.0, 33.9, 31.8, 31.7, 19.9, 14.2; IR (neat) δ 2970, 1694, 1593 cm−1; LC-FAB-MS (M+Na)+ calcd for C25H31NO2Na 400.2253. found 400.2237.
c. (E)-3-(4-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (69)
To a 100 mL round bottom flask containing 68 (1.0417 g, 2.76 mmol) suspended in methanol (6.0 mL) was added a solution of KOH (0.4767 g, 8.50 mmol) in water (0.60 mL), and the solution was refluxed in an oil-bath pre-heated to 85° C. for 1 h. The reaction was allowed to cool to room temperature, and acidified with an aqueous 20% HCl solution (50 mL). The resulting precipitate was filtered and washed with copious amounts of water, and the crude white powder that appeared to be pure by TLC (single spot) 69 (0.9166 g, 95%) as a white crystalline solid that was purified by column chromatography (25 mL SiO2, 1% methanol:ethyl acetate) to give 69 (0.708 g, 74%) as a crystalline solid, m.p. 205-208° C.: 1H NMR (400 MHz, CDCl3) δ 8.90 (d, J=5.6, 1H), 7.97 (d, J=16.0, 1H), 7.87 (s, 1H), 7.77 (d, J=5.2, 1H), 7.35 (d, J=16.4, 1H), 7.27 (s, 1H), 7.21 (s, 1H), 2.32 (s, 3H), 1.70 (s, 4H), 1.31 (s, 6H), 1.29 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 166.4, 159.6, 148.2, 147.4, 144.0, 142.4, 134.5, 133.2, 131.9, 130.0, 129.7, 127.7, 126.5, 126.0, 34.8, 34.7, 34.2, 34.0, 31.8, 31.6, 20.0; IR (neat) δ 2970, 1711, 1603 cm−1; LC-FAB-MS (M+H)+ calcd for C23H28NO2 348.1964. found 348.1953.
Example 4 Synthesis of (E)-3-(5-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-3-yl)acrylic acid (73) (A45)
Using a procedure similar to that described in Example 3, 5-bromonicotinaldehyde (70) was converted to (E)-ethyl 3-(5-bromopyridin-3-yl)acrylate (71) in 93% yield by a Horner-Wadsworth-Emmons reaction (Scheme 9).




The acrylate 71 is reacted with the boronic acid 82 to give (E)-ethyl 3-(5-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-3-yl)acrylate (72) in 88% yield which is saponified to (E)-3-(5-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-3-yl)acrylic acid (73) in 50% yield (Scheme 10).




a. (E)-Ethyl 3-(5-bromopyridin-3-yl)acrylate (71)
To a solution of a 60% dispersion of NaH in mineral oil (0.29 g, 7.25 mmol) in DME (2 mL) at −30° C. was added a solution of ethyl 2-phosphonoacetate (1.46 mL, 7.29 mmol) in DME (13 mL), and the mixture was stirred at this temperature for 30 min. To this solution was added a solution of 5-bromonicotinaldehyde (70) (1.24 g, 6.67 mmol) in DME (3 mL), and the reaction was stirred at −30° C. for 1.5 h and then poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with an aqueous saturated NH4Cl solution and then brine, dried over sodium sulfate, filtered and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 7% ethyl acetate:hexanes to 10% ethyl acetate:hexanes) to give 71 (1.587 g, 93%) as a colorless crystalline solid, m.p. 80-82° C.: 1H NMR (400 MHz, CDCl3) δ 8.65 (d, J=2.0, 1H), 8.64 (d, J=1.6, 1H), 7.99 (dd, J=2.0, 1.6, 1H), 7.59 (d, J=16.0, 1H), 6.50 (d, J=16.0, 1H), 4.27 (q, J=7.2, 2H), 1.33 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 165.77, 151.42, 147.2, 138.9, 136.8, 131.9, 122.1, 121.1, 60.9, 14.2; IR (neat) δ 2983, 1713, 1640 cm−1; LC-FAB-MS (M+H)+ calcd for C10H11BrNO2 255.9973. found 255.9966.
b. (E)-Ethyl 3-(5-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-3-yl)acrylate (72)
To a 50 mL Schlenk flask charged with bromide 71 (0.434 g, 1.61 mmol), boronic acid 82 (0.409 g, 1.66 mmol), TBAB (0.52 g), Na2CO3 (0.51 g, 4.81 mmol), and water (3.7 mL), was added Pd(OAc)2 (0.0203 g, 0.09 mmol), and the flask was evacuated and back-filled with nitrogen three times. The reaction was stirred at room temperature for 15 min and then placed in an oil bath pre-heated to 150° C. and stirred for 5 min. The reaction was allowed to cool to room temperature, and the black residue was taken up in ethyl acetate and water. The layers were separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes to 8% ethyl acetate:hexanes) to give 72 (0.5358 g, 88%) as a white solid, m.p. 114-119° C.: 1H NMR (400 MHz, CDCl3) δ 8.71 (d, J=2.0, 1H), 8.60 (d, J=2.0, 1H), 7.85 (t, J=2.0, 1H), 7.72 (d, J=16.4, 1H), 7.23 (s, 1H), 7.13 (s, 1H), 6.54 (d, J=16.4, 1H), 4.25 (q, J=7.2, 2H), 2.24 (s, 3H), 1.71 (s, 4H), 1.35 (t, J=7.2, 3H), 1.33 (s, 6H), 1.29 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 166.1, 150.2, 146.6, 145.4, 143.1, 140.5, 138.2, 135.4, 134.1, 132.2, 129.9, 128.7, 127.9, 120.9, 60.8, 34.9, 34.0, 33.9, 31.8, 31.7, 20.0, 14.2; IR (neat) δ 2956, 1709, 1644 cm−1; LC-FAB-MS (M+H)+ calcd for C25H32NO2 378.2433. found 378.2441.
c. (E)-3-(5-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-3-yl)acrylic acid (73)
To a 100 mL round bottom flask containing 72 (0.662 g, 1.89 mmol) suspended in methanol (5.0 mL) was added a solution of KOH (0.3013 g, 5.37 mmol) in water (0.38 mL), and the solution was refluxed in an oil-bath pre-heated to 85° C. for 1 h. The reaction was allowed to cool to room temperature, and acidified with an aqueous 20% HCl solution (50 mL). The resulting precipitate was filtered and washed with copious amounts of water, and the crude white powder that was purified by column chromatography (25 mL SiO2, 1% methanol:ethyl acetate) to give 72 (0.3072 g, 50%) as a solid, m.p. 165-168° C.: 1H NMR (400 MHz, CDCl3) δ 8.95-7.88 (m, 5H), 7.13 (s, 1H), 6.74-6.66 (m, 1H), 2.28 (s, 3H), 1.78 (s, 4H), 1.30 (s, 12H); 13C NMR (100.6 MHz, CDCl3) δ 169.7, 149.2, 145.9, 143.3, 141.4, 139.5, 137.3, 133.4, 132.3, 131.2, 130.9, 128.9, 128.3, 122.1, 34.9, 34.9, 34.0, 33.9, 32.0, 31.7, 20.4; IR (neat) δ 2958, 1700, 1643 cm−1; LC-FAB-MS (M−H)− calcd for C23H26NO2 348.1964. found 348.1961.
Example 5 Synthesis of (E)-3-(5-methyl-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (77) (A46)
6-Bromo-5-methylpicolinaldehyde (74) was converted to (E)-ethyl 3-(6-bromo-5-methylpyridin-2-yl)acrylate (75) in 68% yield by a Homer-Wadsworth-Emmons reaction (Scheme 11).




The acrylate 75 is reacted with the boronic acid 82 to give (E)-ethyl 3-(5-methyl-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylate (76) in 57% yield which is saponified to (E)-3-(5-methyl-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (77) in 88% yield (Scheme 12).




a. (E)-Ethyl 3-(6-bromo-5-methylpyridin-2-yl)acrylate (75)
To a solution of a 60% dispersion of NaH in mineral oil (0.29 g, 7.25 mmol) in DME (2 mL) at −30° C. was added a solution of ethyl 2-phosphonoacetate (1.46 mL, 7.29 mmol) in DME (13 mL), and the mixture was stirred at this temperature for 30 min. To this solution was added a solution of 6-bromo-5-methylpicolinaldehyde (74) (1.35 g, 6.75 mmol) in DME (3 mL), and the reaction was stirred at −30° C. for 1.5 h and then poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with an aqueous saturated NH4Cl solution and then brine, dried over sodium sulfate, filtered and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes) to give 75 (1.249 g, 68%) as a colorless crystalline solid, m.p. 59-61° C.: 1H NMR (400 MHz, CDCl3) δ 7.57 (dd, J=15.6, 3.2, 1H), 7.54 (ddd, J=15.2, 7.6, 0.8, 1H), 7.26 (t, J=7.6, 1H), 6.88 (dd, J=15.6, 3.2, 1H), 4.25 (q, J=7.2, 2H), 2.39 (s, 3H), 1.31 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 166.6, 166.5, 151.8, 151.3, 150.9, 145.0, 141.5, 141.3, 139.7, 139.0, 136.0, 133.5, 122.8, 122.7, 122.6, 60.6, 22.0, 19.7, 14.2; IR (neat) δ 2985, 1699, 1642, 1546 cm−1; LC-FAB-MS (M)+ calcd for C11H12BrNO2 [not yet assayed]. found [not yet assayed]. (mix of isomers).
b. (E)-Ethyl 3-(5-methyl-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylate (76)
To a 50 mL Schlenk flask charged with bromide 75 (0.4355 g, 1.61 mmol), boronic acid 82 (0.411 g, 1.67 mmol), TBAB (0.52 g), Na2CO3 (0.51 g, 4.81 mmol), and water (3.7 mL), was added Pd(OAc)2 (0.0203 g, 0.09 mmol), and the flask was evacuated and back-filled with nitrogen three times. The reaction was stirred at room temperature for 15 min and then placed in an oil bath pre-heated to 150° C. and stirred for 5 min. The reaction was allowed to cool to room temperature, and the black residue was taken up in ethyl acetate and water. The layers were separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes) to give 76 (0.359 g, 57%) as a white solid, m.p. 127-130° C.: 1H NMR (400 MHz, CDCl3) δ 7.75 (d, J=15.6, 1H), 7.59 (d, J=8.0, 1H), 7.36 (d, J=8.0, 1H), 7.17 (s, 1H), 7.08, (s, 1H), 6.83 (d, J=15.6, 1H), 4.25 (q, J=7.2, 2H), 2.16, (s, 3H), 2.07 (s, 3H), 1.68 (s, 4H), 1.30 (t, J=7.2, 3H), 1.30 (s, 6H), 1.25 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 166.9, 160.4, 149.9, 144.4, 143.9, 141.9, 138.3, 136.6, 132.8, 128.3, 126.7, 121.6, 121.3, 60.4, 35.2, 35.1, 34.0, 33.9, 31.8, 19.4, 19.3, 14.2; IR (neat) δ 2957, 1713, 1646 1569 cm−1; LC-FAB-MS (M+Na)+ calcd for C26H33NO2Na 414.2409. found 414.2408.
c. (E)-3-(5-Methyl-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (77)
To a 100 mL round bottom flask containing 76 (0.6556 g, 1.67 mmol) suspended in methanol (4.8 mL) was added a solution of KOH (0.2902 g, 5.17 mmol) in water (0.38 mL), and the solution was refluxed in an oil-bath pre-heated to 85° C. for 1 h. The reaction was allowed to cool to room temperature, and acidified with an aqueous 20% HCl solution (50 mL). The resulting precipitate that was purified by column chromatography (25 mL SiO2, ethyl acetate:hexanes 1:1) to give 77 (0.54 g, 88%) as a white crystalline solid, m.p. 230-234° C.: 1H NMR (400 MHz, CDCl3) δ 7.85 (d, J=15.6, 1H), 7.63 (d, J=8.0, 1H), 7.39 (d, J=8.0, 1H), 7.18 (s, 1H), 7.09 (s, 1H), 6.87 (d, J=16.0, 1H), 2.17 (s, 3H), 2.08 (s, 3H), 1.68 (s, 4H), 1.30 (s, 6H), 1.25 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 171.8, 160.3, 149.4, 145.5, 144.6, 142.0, 138.7, 136.1, 133.5, 132.3, 128.3, 126.8, 122.2, 120.8, 35.2, 35.1, 34.0, 33.9, 31.9, 31.8, 19.5, 19.3; IR (neat) δ 2962, 1685, 1637 cm−1; LC-FAB-MS (M−H)− calcd for C24H28NO2 362.2120. found 362.2130.
Example 6 Synthesis of (E)-3-(6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (81) (A47)
Using a procedure similar to that described in Example 5, 6-bromopicolinaldehyde (78) was converted to (E)-ethyl 3-(6-bromopyridin-2-yl)acrylate (79) in 96% yield by a Horner-Wadsworth-Emmons reaction (Scheme 13).




The acrylate 79 is then reacted with the boronic acid 82 to give (E)-ethyl 3-(6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylate (80) in 44% yield which is saponified to (E)-3-(6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (81) in 50% yield (Scheme 14).




a. (E)-Ethyl 3-(6-bromopyridin-2-yl)acrylate (79)
To a solution of a 60% dispersion of NaH in mineral oil (0.29 g, 7.25 mmol) in DME (2 mL) at −30° C. was added a solution of ethyl 2-phosphonoacetate (1.46 mL, 7.29 mmol) in DME (13 mL), and the mixture was stirred at this temperature for 30 min. To this solution was added a solution of 6-bromopicolinaldehyde (78) (1.24 g, 6.67 mmol) in DME (3 mL), and the reaction was stirred at −30° C. for 1.5 h and then poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with an aqueous saturated NH4Cl solution and then brine, dried over sodium sulfate, filtered and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes to 7% ethyl acetate:hexanes) to give 79 (1.6425 g, 96%) as a colorless crystalline solid, m.p. 63-66° C.: 1H NMR (400 MHz, CDCl3) δ 7.57 (d, J=16.0, 1H), 7.55 (t, J=8.0, 1H), 7.44 (dd, J=8.0, 0.8, 1H), 7.34 (dd, J=7.6, 0.8, 1H), 6.93 (d, J=15.6, 1H), 4.26 (q, J=7.2, 2H), 1.32 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 166.3, 154.0, 142.5, 141.2, 138.9, 128.5, 123.9, 122.8, 60.7, 14.2; IR (neat) δ 2957, 1713, 1645, 1569 cm−1; LC-FAB-MS (M+H)+ calcd for C10H11BrNO2 255.9973. found 255.9982.
b. (E)-Ethyl 3-(6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylate (80)
To a 50 mL Schlenk flask charged with bromide 79 (0.4125 g, 1.61 mmol), boronic acid 82 (0.409 g, 1.66 mmol), TBAB (0.52 g), Na2CO3 (0.51 g, 4.81 mmol), and water (3.7 mL), was added Pd(OAc)2 (0.0203 g, 0.09 mmol), and the flask was evacuated and back-filled with nitrogen three times. The reaction was stirred at room temperature for 15 min and then placed in an oil bath pre-heated to 150° C. and stirred for 5 min. The reaction was allowed to cool to room temperature, and the black residue was taken up in ethyl acetate and water. The layers were separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 3% ethyl acetate:hexanes) to give 80 (0.2723 g, 44%) as a white solid, m.p. 107-110° C.: 1H NMR (400 MHz, CDCl3) δ 7.77 (dd, J=15.6, 2.0, 1H), 7.76 (d, J=7.6, 1H), 7.41 (dd, J=7.6, 0.8, 1H), 7.36 (dd, J=7.6, 0.8, 1H), 7.35 (s, 1H), 7.22 (s, 1H), 6.97 (d, J=15.6, 1H), 4.27 (q, J=7.2, 2H), 2.38 (s, 3H), 1.70 (s, 4H), 1.33 (t, J=7.2, 3H), 1.30 (s, 12H); 13C NMR (100.6 MHz, CDCl3) δ 166.9, 160.6, 151.9, 145.3, 143.4, 142.5, 137.0, 136.9, 132.9, 129.0, 127.9, 124.5, 122.3, 121.7, 60.5, 35.0, 34.0, 33.9, 31.9, 31.8, 20.2, 14.2; IR (neat) δ 2956, 1710, 1645 cm−1; LC-FAB-MS (M+Na)+ calcd for C25H31NO2Na 400.2253. found 400.2247.
c. (E)-3-(6-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)pyridin-2-yl)acrylic acid (81)
To a 100 mL round bottom flask containing 80 (0.4752 g, 1.26 mmol) suspended in methanol (3.6 mL) was added a solution of KOH (0.2328 g, 4.15 mmol) in water (0.28 mL), and the solution was refluxed in an oil-bath pre-heated to 85° C. for 1 h. The reaction was allowed to cool to room temperature, and acidified with an aqueous 20% HCl solution (52 mL). The resulting precipitate was filtered and washed with copious amounts of water, and the crude white powder that was purified by column chromatography (25 mL SiO2, 1% methanol:ethyl acetate) to give 81 (0.2467 g, 56%) as a solid, m.p. 261-263° C.: 1H NMR (400 MHz, CDCl3) δ 7.86-7.79 (m, 2H), 7.44 (d, J=4.8, 1H), 7.43-7.35 (m, 2H), 7.22 (s, 1H), 7.00 (d, J=14.4, 1H), 2.39 (s, 3H), 1.70 (s, 4H), 1.31 (s, 6H), 1.30 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 171.5, 171.3, 160.8, 151.5, 145.8, 145.5, 142.6, 137.2, 136.9, 132.9, 129.1, 128.1, 125.0, 122.4, 121.6, 35.1, 34.0, 33.9, 31.9, 31.8, 20.4; IR (neat) δ 2957, 1671, 1643, 1629, 1579 cm−1; LC-FAB-MS (M−H)− calcd for C23H26NO2 348.1964. found 348.1973.
Example 7 Synthesis of Net-TMN (A54)




The route of Kakuta and co-workersi was followed to reproduce NEt-TMN. Commercially available 1,1,4,4-tetramethyl-6-nitro-1,2,3,4-tetrahydronaphthalene (73) was dissolved in ethyl acetate to give a 0.05 M solution, and nitro-aromatic 73 was converted to 5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-amine (74) in 99% yield by catalytic hydrogenation using a hydrogenation flow reactor. Amine (74) was mixed with methyl 6-chloronicotinate and p-TsOH and refluxed in 1,4-dioxane for 18 h to give methyl 6-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (75) in 61% yield. Amine (75) in DMF was treated with sodium hydride and ethyl iodide was added to provide methyl 6-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (76) in 68% yield. Finally, methyl ester 76 was saponified to NEt-TMN in 76% yield by refluxing a solution of 76 in methanol with potassium hydroxide followed by acidification with hydrochloric acid.
a. 5,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalen-2-amine (74)
A 0.05 M solution of 1,1,4,4-tetramethyl-6-nitro-1,2,3,4-tetrahydronaphthalene (73) (2.5 g, 10.7 mmol) in ethyl acetate (210 mL) was passed through a 10% Pd/C cartridge at 1.0 mL/minute, twice, in the ThalesNano H-cube® at 70° C. and 2-5 bar pressure. The resulting solution was concentrated in vacuo to give 74 (2.1532 g, 99%) as a yellow, crystalline solid, m.p. 58-60° C.: 1H NMR (400 MHz, CDCl3) δ 7.11 (d, J=8.4, 1H), 6.65 (d, J=2.4, 1H), 6.54 (dd, J=8.4, 2.4, 1H), 3.62 (br s, 2H), 1.66 (s, 4H), 1.26 (s, 6H), 1.25 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 145.8, 143.3, 135.4, 127.3, 113.7, 112.9, 35.2, 34.1, 33.5, 31.9, 31.7; IR (neat) 3405, 3208, 2952, 2920, 1612, 1499 cm−1; LC-MS-CI (M+H)+ calcd for C14H22N 204.1752. found 204.1747.
b. Methyl 6-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (75)
To a 100 mL, one-neck, round-bottomed flask equipped with a magnetic stir bar and charged with 74 (0.8047 g, 3.958 mmol), methyl 6-chloronicotinate (0.6897, 4.02 mmol), and p-TsOH (0.7605 g, 4.0 mmol) was added 1,4-dioxane (15 mL). The flask was fitted with a reflux condenser, evacuated and back-filled with nitrogen, heated to reflux and stirred in an oil bath at 111° C. for 14 h. After cooling the reaction to r.t., the reaction mixture was poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 10% ethyl acetate:hexanes) to give 75 (0.8152 g, 61%) as a white crystalline solid, m.p. 167-171° C.: 1H NMR (400 MHz, CDCl3) δ 8.81 (dd, J=2.0, 0.4, 1H), 8.02 (dd, J=8.8, 2.0, 1H), 7.94 (s, 1H), 7.31 (d, J=7.6, 1H), 7.21 (d, J=2.4, 1H), 7.12 (dd, J=8.4, 2.4, 1H), 6.82 (dd, J=8.8, 0.4, 1H), 3.87 (s, 3H), 1.70 (s, 4H), 1.29 (s, 12H); 13C NMR (100.6 MHz, CDCl3) δ 166.0, 159.4, 151.2, 146.3, 141.5, 138.9, 136.1, 127.5, 120.4, 120.0, 116.3, 106.0, 51.6, 35.0, 34.9, 34.3, 33.9, 31.8, 31.7; IR (neat) 3224, 2954, 1715, 1597, 1535, 1261 cm−1; ES-MS (M+Na)+ calcd for C21H26N2O2Na 361.1892. found 361.1899.
c. Methyl 6-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (76)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.210 g, 5.25 mmol). The dispersion of sodium hydride was washed with hexanes (3 mL, twice) and dried under vacuum and suspended in 3.1 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 75 (0.8386 g, 2.478 mmol) in DMF (8.3 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.34 mL, 4.25 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 76 (0.619 g, 68%) as a white crystalline solid, m.p. 114-116° C.: 1H NMR (400 MHz, CDCl3) δ 8.83 (dd, J=2.4, 0.4, 1H), 7.78 (dd, J=9.2, 2.4, 1H), 7.35 (d, J=8.4, 1H), 7.11 (d, J=2.0, 1H), 6.95 (dd, J=8.4, 2.4, 1H), 6.21 (d, J=9.2, 1H), 4.02 (q, J=7.2, 2H), 3.85 (s, 3H), 1.70 (s, 4H), 1.31 (s, 6H), 1.25 (s, 6H), 1.22 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 166.6, 160.4, 151.0, 146.9, 143.8, 140.9, 137.2, 128.1, 125.8, 124.8, 114.2, 107.4, 51.5, 45.3, 35.0, 34.9, 34.4, 34.1, 31.8, 31.8, 13.0; IR (neat) 2956, 1708, 1596, 1267 cm−1; ES-MS (M+Na)+ calcd for C23H30H2O2Na 389.2205. found 389.2211.
d. NEt-TMN
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 76 (0.3674 g, 1.002 mmol) suspended in methanol (3.5 mL) was added a solution of potassium hydroxide (0.1767 g, 3.15 mmol) in water (0.22 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (52 mL). The crude white precipitate was filtered and washed with cold water to provide crude NEt-TMN (0.3238 g, 91%) and this crude material was purified by column chromatography (25 mL SiO2, 30% ethyl acetate:hexanes to pure ethyl acetate to 2% methanol:ethyl acetate) to give NEt-TMN (0.2677 g, 76%) as a white crystalline solid, m.p. 230-232° C. (lit. 235.7-237.7° C.): 1H NMR (400 MHz, d6-DMSO) δ 12.44 (br s, 1H), 8.66 (dd, J=2.4, 0.4, 1H), 7.78 (dd, J=8.8, 2.4, 1H), 7.43 (d, J=8.0, 1H), 7.18 (d, J=2.0, 1 H), 7.01 (dd, J=8.4, 2.4, 1H), 6.19 (dd, J=9.2, 0.4, 1H), 3.94 (q, J=6.8, 2H), 1.66 (s, 4H), 1.26 (s, 6H), 1.22 (s, 6H), 1.22 (t, J=6.8, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 166.6, 159.7, 150.5, 146.5, 143.1, 140.7, 137.6, 128.1, 125.4, 124.8, 114.7, 106.7, 44.7, 34.5. 34.4, 34.0, 33.8, 31.5, 31.4, 12.7; IR (neat) 2925, 1666, 1592, 1409, 1274 cm−1; ES-MS (M−H)− calcd for C22H27N2O2 351.2072. found 351.2073. Anal. Calcd for C22H28N2O2: C, 74.97; H, 8.01; N, 7.95. Found: C, 74.74; H, 8.38; N, 7.56.
Example 8 Synthesis of 6-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinic acid (81) (A55)




First, 6-bromo-1,1,4,4,7-pentamethyl-1,2,3,4-tetrahydronaphthalene (77) was coupled to methyl 6-aminonicotinate (78) in a tris(dibenzylideneacetone)dipalladium(0) catalytic system employing racemic BINAP to give methyl 6-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (79) in 37% purified yield. Methyl ester 79 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 6-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (80) in 78% purified yield. The methyl ester of 80 was saponified by refluxing 80 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to give 6-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinic acid (81).
a. Methyl 6-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (79)
To a solution of 77 (1.1216 g, 3.99 mmol), 78 (0.5910 g, 3.88 mmol), CsCO3 (3.1158 g, 9.58 mmol), rac-BINAP (0.1856 g, 0.30 mmol) in toluene (4.5 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.1755 g, 0.19 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 6.5% ethyl acetate:hexanes to 10% ethyl acetate: hexanes) to give 79 (0.5072 g, 37%) as a crystalline solid, m.p. 169-175.8° C.: 1H NMR (400 MHz, CDCl3) δ 8.79 (dd, J=2.4, 0.8, 1H), 8.00 (dd, J=8.8, 2.0, 1H), 7.25 (s, 1H), 7.18 (s, 1H), 7.05 (br s, 1H), 6.49 (dd, J=8.8, 0.8, 1H), 3.87 (s, 3H), 2.20 (s, 3H), 1.68 (s, 4H), 1.29 (s, 6H), 1.25 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 166.1, 160.0, 151.3, 143.8, 143.0, 138.9, 134.1, 130.3, 129.1, 123.1, 116.1, 105.5, 51.7, 35.0, 34.9, 34.0, 33.9, 31.8, 31.8, 17.6; IR (neat) 2961, 1722, 1605, 1399, 1273 cm−1; ES-MS (M+Na)+ calcd for C22H28N2O2Na 375.2048. found 375.2050.
b. Methyl 6-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinate (80)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.2649 g, 6.6 mmol). The dispersion of sodium hydride was washed with hexanes (3.7 mL, twice) and dried under vacuum and suspended in 3.8 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 79 (1.0615 g, 3.01 mmol) in DMF (11.4 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.36 mL, 4.5 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 80 (0.9012 g, 78%) as a white crystalline solid, m.p. 100.1-102.4° C.: 1H NMR (400 MHz, CDCl3) δ 8.85 (dd, J=2.4, 0.4, 1H), 7.78 (dd, J=9.2, 2.4, 1H), 7.21 (s, 1H), 7.00 (s, 1H), 5.91 (d, J=8.8, 1H), 4.32-4.23 (m, 1H), 3.84 (s, 3H), 3.67-3.59 (m, 1H), 2.04 (s, 3H), 1.69 (s, 4H), 1.30 (d, J=8.0, 6H), 1.23 (t, J=7.2, 9H); 13C NMR (100.6 MHz, CDCl3) δ 166.7, 160.2, 151.2, 144.6, 144.5, 139.1, 137.5, 132.8, 129.4, 127.0, 113.9, 106.7, 51.5, 44.5, 35.0, 34.9, 34.1, 34.0, 31.8, 17.2, 13.0; IR (neat) 2953, 1708, 1598, 1504, 1269, 1111 cm−1; ES-MS (M+Na)+ calcd for C24H32N2O2Na 403.2361. found 403.2365.
c. 6-(Ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinic acid (81)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 80 (0.5059 g, 1.33 mmol) suspended in methanol (4.6 mL) was added a solution of potassium hydroxide (0.2408 g, 4.29 mmol) in water (0.29 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (72 mL). The solution was extracted with ethyl acetate (2×70 mL), and the organic layers were dried over sodium sulfate and concentrated in vacuo to give a crude product that was purified by column chromatography (25 mL SiO2, 30% ethyl acetate:hexanes to 60% ethyl acetate:hexanes) to give pure 81 (0.4448 g, 91%) as a white crystalline solid, m.p. 250.2-251.0° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.42 (br s, 1H), 8.66 (d, J=2.0, 1H), 7.78 (dd, J=8.8, 2.0, 1H), 7.32 (s, 1H), 7.07 (s, 1H), 5.89 (br s, 1H), 4.19-4.05 (m, 1H), 3.65-3.55 (m, 1H), 1.98 (s, 3H), 1.64 (s, 4H), 1.26 (d, J=6.4, 6H), 1.20 (s, 6H), 1.13 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 166.6, 159.5, 150.7, 144.1, 143.8, 139.0, 137.9, 132.5, 129.2, 126.5, 114.4, 105.9, 44.0, 34.5, 34.4, 33.7, 31.6, 31.5, 16.9, 12.7; IR (neat) 2960, 1669, 1595, 1509, 1412, 1266 cm−1; ES-MS (M−H)− calcd for C23H29N2O2 365.2229. found 365.2235. Anal. Calcd for C23H30N2O2: C, 75.37; H, 8.25; N, 7.64. Found: C, 75.33; H, 8.46; N, 7.56.
Example 9 Synthesis of 2-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylic acid (84) (A56)
Amine (74) was mixed with methyl 2-chloropyrimidine and p-TsOH and refluxed in 1,4-dioxane for 18 h to give methyl 2-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (82) in 75% yield. Amine (82) in DMF was treated with sodium hydride and ethyl iodide was added to provide methyl 2-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (83) in 75% yield. Finally, methyl ester 83 was saponified to 84 in 97% yield by refluxing a solution of 83 in methanol with potassium hydroxide followed by acidification with hydrochloric acid (Scheme 17).




a. Methyl 2-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (82)
To a 100 mL, one-neck, round-bottomed flask equipped with a magnetic stir bar and charged with 74 (0.8047 g, 3.958 mmol), methyl 6-chloronicotinate (0.6897, 4.02 mmol), and p-TsOH (0.8101 g, 3.98 mmol) was added 1,4-dioxane (15 mL). The flask was fitted with a reflux condenser, evacuated and back-filled with nitrogen, heated to reflux and stirred in an oil bath at 111° C. for 14 h. After cooling the reaction to r.t., the reaction mixture was poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 10% ethyl acetate:hexanes to 12% ethyl acetate:hexanes) to give 82 (1.0177 g, 75%) as a white crystalline solid, m.p. 143.2-149.3° C.: 1H NMR (400 MHz, CDCl3) δ 8.95 (s, 2H), 8.25 (br s, 1H), 7.47 (dd, J=8.4, 2.4, 1H), 7.42 (d, J=2.0, 1H), 7.32 (d, J=8.4, 1H), 3.90 (s, 3H), 1.69 (s, 4H), 1.30 (s, 6H), 1.28 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 164.7, 161.4, 145.7, 141.1, 135.3, 127.1, 118.8, 118.7, 114.7, 51.9, 35.0, 34.3, 33.9, 31.8, 31.8; IR (neat) 3254, 2954, 1720, 1597, 1526, 1433, 1289, 1258, 1123 cm−1; ES-MS (M+Na)+ calcd for C20H25N3O2Na 362.1844. found 362.1844.
b. Methyl 2-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (83)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.251 g, 6.3 mmol). The dispersion of sodium hydride was washed with hexanes (3 mL, twice) and dried under vacuum and suspended in 3.6 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 82 (0.9851 g, 2.9 mmol) in DMF (10.9 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.35 mL, 4.38 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 83 (0.7997 g, 75%) as a white crystalline solid, m.p. 181.2-183.9° C.: 1H NMR (400 MHz, CDCl3) δ 8.85 (s, 1H), 7.33 (d, J=8.4, 1H), 7.13 (d, J=2.4, 1H), 7.00 (d, J=2.4, 1H), 6.98 (d, J=2.0, 1H), 4.03 (q, J=7.2, 2H), 3.86 (s, 3H), 1.69 (s, 4H), 1.30 (s, 6H), 1.26 (s, 6H), 1.24 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 165.3, 162.4, 159.7, 146.0, 143.3, 140.3, 127.4, 125.1, 124.2, 112.9, 51.6, 46.5, 35.0, 34.9, 34.3, 34.1, 31.8, 31.8, 12.8; IR (neat) 2930, 1706, 1594, 1504, 1284, 1122 cm−1; ES-MS (M+Na)+ calcd for C22H29N3O2Na 390.2158. found 390.2155.
c. 2-(Ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylic acid (84)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 83 (0.3925 g, 1.07 mmol) suspended in methanol (4.2 mL) was added a solution of potassium hydroxide (0.1947 g, 3.47 mmol) in water (0.26 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (76 mL). The crude white precipitate was filtered and washed with cold water to provide crude 84 and this crude material was purified by column chromatography (25 mL SiO2, 40% ethyl acetate:hexanes to pure ethyl acetate) to give 84 (0.3668 g, 97%) as a white crystalline solid, m.p. 249.5-250.6° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.62 (br s, 1H), 8.37 (s, 1H), 7.35 (d, J=8.4, 1H), 7.17 (d, J=2.4, 1H), 7.00 (dd, J=8.4, 2.0, 1H), 3.99 (q, J=7.2, 2H), 1.67 (s, 4H), 1.27 (s, 6H), 1.24 (s, 6H), 1.16 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 165.1, 161.9, 159.1, 15.2, 142.3, 140.2, 126.8, 124.7, 124.6, 113.5, 45.3, 34.4, 34.4, 33.7, 33.5, 31.4, 31.3, 12.3; IR (neat) 2962, 1664, 1586, 1515, 1426, 1278 cm−1; ES-MS (M−H)− calcd for C21H26N3O2 352.2025. found 352.2024. Anal. Calcd for C21H27N3O2: C, 71.36; H, 7.70; N, 11.89. Found: C, 71.40; H, 7.98; N, 11.79.
Example 10 Synthesis of 2-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylic acid (88) (A57)




First, 6-bromo-1,1,4,4,7-pentamethyl-1,2,3,4-tetrahydronaphthalene (77) was coupled to methyl 2-aminopyrimidine-5-carboxylate (85) in a tris(dibenzylideneacetone)dipalladium(0) catalytic system employing racemic BINAP to give methyl 2-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (86) in 45% purified yield. Methyl ester 86 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 2-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (87) in 65% purified yield. The methyl ester of 87 was saponified by refluxing 87 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to give 2-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylic acid (88).
a. Methyl 2-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (86)
To a solution of 77 (1.1216 g, 3.99 mmol), 85 (0.5985 g, 3.91 mmol), CsCO3 (3.12 g, 9.58 mmol), rac-BINAP (0.1891 g, 0.30 mmol) in toluene (4.5 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.1780 g, 0.19 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes to 10% ethyl acetate: hexanes) to give 86 (0.6206 g, 45%) as a crystalline solid, m.p. 135.6-145.6° C.: 1H NMR (400 MHz, CDCl3) δ 8.92 (s, 2H), 7.65 (s, 1H), 7.45 (br s, 1H), 7.16 (s, 1H), 3.89 (s, 3H), 2.24 (s, 3H), 1.68 (s, 4H), 1.29 (s, 6H), 1.28 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 164.8, 162.0, 160.2, 143.4, 133.2, 128.7, 128.4, 122.1, 114.6, 51.8, 35.1, 35.0, 34.1, 33.9, 31.8, 31.7, 17.8; IR (neat) 3250, 2954, 1718, 1598, 1527, 1430, 1286 cm−1; ES-MS (M+Na)+ calcd for C21H27N3O2Na 376.2001. found 376.1998.
b. Methyl 2-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylate (87)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.2622 g, 6.56 mmol). The dispersion of sodium hydride was washed with hexanes (3.7 mL, twice) and dried under vacuum and suspended in 3.4 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 86 (0.974 g, 2.76 mmol) in DMF (10.3 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.34 mL, 4.25 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 87 (0.688 g, 65%) as a white crystalline solid, m.p. 159.2-161.0° C.: 1H NMR (400 MHz, CDCl3) δ 8.93 (s, 1H), 8.78 (s, 1H), 7.19 (s, 1H), 7.00 (s, 1H), 4.15 (sextet, J=7.2, 1H), 3.85 (s, 3H), 3.74 (sextet, J=7.2, 1H), 2.05 (s, 3H), 1.68-1.66 (m, 4H), 1.32 (s, 3H), 1.27 (s, 3H), 1.26 (s, 3H), 1.25 (s, 3H), 1.24 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 165.4, 162.3, 160.0, 159.8, 143.8, 143.7, 139.2, 132.1, 129.0, 125.8, 112.6, 51.6, 46.0, 35.1, 34.9, 34.0, 34.0, 32.0, 32.0, 31.7, 31.6, 17.5, 12.7; IR (neat) 2955, 1703, 1594, 1513, 1279, 1267, 1126, 1099 cm−1; ES-MS (M+Na)+ calcd for C23H31N3O2Na 404.2314. found 404.2312.
c. 2-(Ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrimidine-5-carboxylic acid (88)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 87 (0.3892 g, 1.04 mmol) suspended in methanol (3.5 mL) was added a solution of potassium hydroxide (0.1789 g, 3.19 mmol) in water (0.22 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (53 mL). The precipitate was filtered to give 0.3547 g (92%) of a crude product that was purified by column chromatography (25 mL SiO2, 40% ethyl acetate:hexanes to ethyl acetate) to give pure 88 (0.3203 g, 84%) as a white crystalline solid, m.p. 231.9-233.1° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.60 (br s, 1H), 8.74 (br s, 2H), 7.23 (s, 1H), 7.05 (s, 1H), 4.04 (sextet, J=7.2, 1H), 3.76 (sextet, J=7.2, 1H), 1.97 (s, 3H), 1.65 (s, 4H), 1.29, (s, 3H), 1.26 (s, 3H), 1.23 (s, 3H), 1.20 (s, 3H), 1.16 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 165.2, 161.7, 159.3, 143.0, 142.9, 139.1, 132.0, 128.2, 125.4, 113.2, 45.0, 34.5, 34.4, 33.4, 33.3, 31.5, 31.4, 31.2, 16.9, 12.3; IR (neat) 2952, 1663, 1591, 1508, 1426, 1281 cm−1; ES-MS (M−H)− calcd for C22H28N3O2 366.2181. found 366.2185. Anal. Calcd for C22H29N3O2: C, 71.90; H, 7.95; N, 11.43. Found: C, 71.81; H, 8.23; N, 11.31.
Example 11 Synthesis of 5-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylic acid (91) (A58)
Amine (74) was mixed with methyl 5-chloropyrazine-2-carboxylate and p-TsOH and refluxed in 1,4-dioxane for 18 h to give methyl 5-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (89) in 56% yield. Amine (89) in DMF was treated with sodium hydride and ethyl iodide was added to provide methyl 5-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (90) in 51% yield. Finally, methyl ester 90 was saponified to 91 in 71% yield by refluxing a solution of 90 in methanol with potassium hydroxide followed by acidification with hydrochloric acid (Scheme 19).




a. Methyl 5-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (89)
To a 100 mL, one-neck, round-bottomed flask equipped with a magnetic stir bar and charged with 74 (0.8154 g, 4.01 mmol), methyl 5-chloropyrazine-2-carboxylate (0.6897, 4.04 mmol), and p-TsOH (0.7757 g, 4.08 mmol) was added 1,4-dioxane (15 mL). The flask was fitted with a reflux condenser, evacuated and back-filled with nitrogen, heated to reflux and stirred in an oil bath at 111° C. for 14 h. After cooling the reaction to r.t., the reaction mixture was poured into water (50 mL) and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 10% ethyl acetate:hexanes) to give 89 (0.7674 g, 56%) as a white crystalline solid, m.p. 183.2-184.8° C.: 1H NMR (400 MHz, CDCl3) δ 8.83 (d, J=1.6, 1H), 8.26 (d, J=1.2, 1H), 7.53 (br s, 1H), 7.33 (d, J=8.4, 1H), 7.32 (d, J=2.4, 1H), 7.21 (dd, J=8.4, 2.4, 1H), 3.95 (s, 3H), 1.68 (s, 4H), 1.27 (s, 6H), 1.26 (s, 6H); 13C NMR (100.6 MHz, CDCl3) 164.9, 153.8, 146.3, 145.4, 142.1, 134.9, 132.6, 131.6, 127.7, 119.5, 119.2, 52.3, 34.9, 34.8, 34.3, 34.0, 31.7; IR (neat) 3325, 2952, 1713, 1527, 1281 cm−1; ES-MS (M+Na)+ calcd for C20H25N3O2Na 362.1844. found 362.1846.
b. Methyl 5-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (90)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.2116 g, 5.29 mmol). The dispersion of sodium hydride was washed with hexanes (3 mL, twice) and dried under vacuum and suspended in 2.8 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 89 (0.7637 g, 2.25 mmol) in DMF (8.4 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.27 mL, 3.4 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 90 (0.4189 g, 51%) as a white crystalline solid, m.p. 125.0-126.9° C.: 1H NMR (400 MHz, CDCl3) δ 8.82 (d, J=1.6, 1H), 7.66 (d, J=1.2, 1H), 7.39 (d, J=8.4, 1H), 7.12 (d, J=2.4, 1H), 6.95 (dd, J=8.4, 2.4, 1H), 4.00 (q, J=7.2, 2H), 3.92 (s, 3H), 1.69 (s, 4H), 1.29 (s, 6H), 1.24 (s, 6H), 1.23 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 165.4, 155.2, 147.3, 145.3, 144.7, 139.2, 131.7, 131.7, 130.3, 128.6, 125.4, 124.3, 52.1, 45.4, 34.9, 34.8, 34.4, 34.2, 31.8, 31.7; IR (neat) 2956, 1703, 1564, 1527, 1279 cm−1; ES-MS (M+Na)+ calcd for C22H29N3O2Na 390.2158. found 390.2146.
c. 5-(Ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylic acid (91)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 90 (0.3681 g, 1.00 mmol) suspended in methanol (3.5 mL) was added a solution of potassium hydroxide (0.1794 g, 3.2 mmol) in water (0.22 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (56 mL). The crude white precipitate was filtered and washed with cold water to provide crude 91 (0.3216 g, 91%) and this crude material was purified by column chromatography (25 mL SiO2, 0.5% acetic acid:ethyl acetate to 4% acetic acid:ethyl acetate) to give 91 (0.2516 g, 71%) as a white crystalline solid, m.p. 213.1-214.4° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.59 (br s, 1H), 8.70 (d, J=1.6, 1H), 7.61 (d, J=1.2, 1H), 7.47 (d, J=8.0, 1H), 7.29 (d, J=2.4, 1H), 7.10 (dd, J=8.4, 2.4, 1H), 3.94 (q, J=7.1, 2H), 1.66 (s, 4H), 1.27 (s, 6H), 1.23 (s, 6H), 1.14 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 165.4, 154.4, 146.7, 144.6, 143.8, 139.2, 130.8, 130.7, 128.4, 125.2, 124.4, 44.9, 34.4, 34.4, 34.1, 33.8, 31.5, 31.4, 12.2; IR (neat) 2931, 1671, 1556, 1416, 1276 cm−1; ES-MS (M−H)− calcd for C21H26N3O2 352.2025. found 352.2020. Anal. Calcd for C21H27N3O2: C, 71.36; H, 7.70; N, 11.89. Found: C, 70.43; H, 7.64; N, 11.61.
Example 12 Synthesis of 5-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylic acid (95) (A59)




6-Bromo-1,1,4,4,7-pentamethyl-1,2,3,4-tetrahydronaphthalene (77) was coupled to methyl 5-aminopyrazine-2-carboxylate (92) in a tris(dibenzylideneacetone)dipalladium(0) catalytic system employing racemic BINAP to give methyl 5-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (93) in 63% purified yield. Methyl ester 93 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 5-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (94) in 25% purified yield. The methyl ester of 94 was saponified by refluxing 94 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to give 5-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylic acid (95) in 57% yield.
a. Methyl 5-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (93)
To a solution of 77 (1.1303 g, 4.02 mmol), 92 (0.5969 g, 3.90 mmol), CsCO3 (3.12 g, 9.58 mmol), rac-BINAP (0.1868 g, 0.30 mmol) in toluene (4.5 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.1780 g, 0.19 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 20% ethyl acetate:hexanes to 25% ethyl acetate: hexanes) to give 93 (0.8727 g, 63%) as a crystalline solid, m.p. 134.9-137.1° C.: 1H NMR (400 MHz, CDCl3) δ 8.81 (d, J=1.2, 1H), 8.08 (d, J=1.6, 1H), 7.32 (s, 1H), 7.20 (s, 1H), 7.03 (br s, 1H), 3.95 (s, 3H), 2.22 (s, 3H), 1.68 (s, 4H), 1.28 (s, 6H), 1.24 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 164.8, 154.3, 145.4, 144.1, 143.6, 132.8, 130.7, 129.5, 129.3, 122.2, 52.3, 34.9, 34.8, 34.1, 33.9, 31.8, 31.7, 17.6; IR (neat) 3162, 2961, 1712, 1542, 1306, 1271, 1129 cm−1; ES-MS (M+Na)+ calcd for C21H27N3O2Na 376.2001. found 376.2006.
b. Methyl 5-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylate (94)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.2286 g, 5.7 mmol). The dispersion of sodium hydride was washed with hexanes (3.0 mL, twice) and dried under vacuum and suspended in 2.9 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 93 (0.8405 g, 2.38 mmol) in DMF (8.9 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.30 mL, 3.8 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 15% ethyl acetate:hexanes) to give 94 (0.226 g, 25%) as a white crystalline solid, m.p. 115.0-119.5° C.: 1H NMR (400 MHz, CDCl3) δ 8.84 (d, J=1.2, 1H), 7.38 (br s, 1H), 7.24 (s, 1H), 7.00 (s, 1H), 4.24 (sextet, J=7.2, 1H), 3.91 (s, 3H), 3.59 (sextet, J=7.2, 1H), 2.06 (s, 3H), 1.68 (s, 4H), 1.29 (s, 6H), 1.24 (s, 3H), 1.24 (t, J=7.2, 3H), 1.19 (s, 3H); 13C NMR (100.6 MHz, CDCl3) δ 165.4, 155.0, 145.4, 145.3, 145.0, 137.5, 132.4, 131.2, 130.2, 129.8, 126.6, 52.1, 44.5, 34.9, 34.8, 34.1, 34.0, 31.9, 31.8, 31.7, 17.1, 12.4; IR (neat) 2928, 1702, 1567, 1524, 1273, 1129 cm−1; ES-MS (M+Na)+ calcd for C23H31N3O2Na 404.2314. found 404.2305.
c. 5-(Ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)pyrazine-2-carboxylic acid (95)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 94 (0.2309 g, 0.605 mmol) suspended in methanol (2.1 mL) was added a solution of potassium hydroxide (0.1096 g, 1.95 mmol) in water (0.18 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (36 mL). The precipitate was filtered to give 0.2060 g (92%) of a crude product that was purified by column chromatography (25 mL SiO2, 0.5% acetic acid:ethyl acetate to 4% acetic acid:ethyl acetate) to give pure 95 (0.126 g, 57%) as a white crystalline solid, m.p. 203.6-205.1° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.69 (br s, 1H), 8.70 (s, 1H), 7.36 (br s, 2H), 7.15 (s, 1H), 4.15-4.05 (m, 1H), 3.59 (sextet, J=7.2, 1H), 2.03 (s, 3H), 1.65 (s, 4H), 1.29, (s, 3H), 1.26 (s, 3H), 1.22 (s, 3H), 1.20 (s, 3H), 1.15 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 165.4, 154.2, 144.8, 144.4, 144.3, 137.6, 132.3, 130.8, 130.0, 129.5, 126.4, 44.1, 34.5, 34.4, 33.7, 31.6, 31.5, 16.8, 12.1; IR (neat) 2959, 1671, 1557, 1524, 1417, 1286 cm−1; ES-MS (M−H)− calcd for C22H28N3O2 366.2181. found 366.2179. Anal. Calcd for C22H29N3O2: C, 71.90; H, 7.95; N, 11.43. Found: C, 71.62; H, 8.21; N, 11.19.
Example 13 Synthesis of 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoic acid (99) (A63)




Amine (74) was coupled to 4-iodo-methylbenzoate (96) in a tris(dibenzylideneacetone)-dipalladium(0) catalytic system employing racemic BINAP to give methyl 4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (97) in 62% purified yield. Methyl ester 97 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (98) in 56% purified yield. The methyl ester of 98 was saponified by refluxing 98 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to give 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoic acid (99) in 84% yield.
a. Methyl 4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (97)
To a solution of 74 (0.8360 g, 4.11 mmol), 96 (1.0919 g, 4.17 mmol), CsCO3 (3.12 g, 9.58 mmol), rac-BINAP (0.1992 g, 0.32 mmol) in toluene (4.5 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.1870 g, 0.20 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 3.5% ethyl acetate:hexanes) to give 97 (0.8569 g, 62%) as a crystalline solid, m.p. 118-124.7° C.: 1H NMR (400 MHz, CDCl3) δ 7.90 (d, J=6.8, 1H), 7.27 (d, J=8.4, 1H), 7.10 (d, J=2.4, 1H), 6.96 (dd, J=8.4, 2.8, 1H), 6.93 (d, J=6.8, 2.0 1H), 6.01 (br s, 1H), 3.87 (s, 3H), 1.70 (s, 4H), 1.29 (s, 6H), 1.27 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 167.0, 148.7, 146.1, 140.2, 137.8, 131.8, 127.5, 120.3, 118.9, 118.7, 113.9, 51.6, 35.0, 35.0, 34.3, 33.8, 31.8, 31.7; IR (neat) 3354, 2954, 1693, 1586, 1276 cm−1; ES-MS (M+Na)+ calcd for C22H27NO2Na 360.1939. found 360.1936.
b. Methyl 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (98)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.1933 g, 4.8 mmol). The dispersion of sodium hydride was washed with hexanes (2.6 mL, twice) and dried under vacuum and suspended in 2.7 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 97 (0.7204 g, 2.13 mmol) in DMF (8.0 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.26 mL, 3.3 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 98 (0.7803 g, 56%) as a white crystalline solid, m.p. 105.3-106.3° C.: 1H NMR (400 MHz, CDCl3) δ 7.83 (d, J=12.0, 1H), 7.31 (d, J=8.4, 1H), 7.10 (d, J=2.4, 1H), 6.92 (dd, J=8.4, 2.4, 1H), 6.67 (d, J=12.0, 1H), 3.91 (s, 3H), 3.76 (q, J=7.2, 2H), 1.70 (s, 4H), 1.31 (s, 6H), 1.24 (s, 6H), 1.24 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 167.3, 151.7, 146.6, 142.9, 142.6, 131.0, 127.9, 125.2, 124.2, 117.8, 112.7, 51.4, 46.6, 35.0, 34.9, 34.3, 34.0, 31.8, 31.7, 12.4; IR (neat) 2953, 1702, 1596, 1266 cm−1; ES-MS (M+Na)+ calcd for C24H31NO2Na 388.2253. found 388.2256.
c. 4-(Ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoic acid (99)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 98 (0.3742 g, 1.02 mmol) suspended in methanol (3.6 mL) was added a solution of potassium hydroxide (0.2029 g, 3.62 mmol) in water (0.24 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (56 mL). The precipitate was filtered to give 0.3516 g (97%) of a crude product that was purified by column chromatography (25 mL SiO2, 20% ethyl acetate:hexanes to 50% ethyl acetate:hexanes) to give pure 99 (0.3043 g, 84%) as a white crystalline solid, m.p. 247.8-250.6° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.14 (br s, 1H), 7.69 (d, J=9.2, 2H), 7.38 (d, J=8.4, 1H), 7.12 (d, J=2.0, 1H), 6.95 (dd, J=8.4, 2.4, 1H), 6.64 (d, J=8.8, 2H), 3.72 (q, J=7.2, 1H), 1.65 (s, 4H), 1.26, (s, 6H), 1.21 (s, 6H), 1.13 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 167.2, 151.1, 146.1, 142.6, 141.9, 130.9, 127.9, 124.6, 124.1, 118.2, 112.6, 34.5, 34.4, 34.0, 33.7, 31.5, 31.4, 12.1; IR (neat) 2955, 1661, 1594, 1270, 1180 cm−1; ES-MS (M−H)− calcd for C23H28NO2 350.2120. found 350.2122. Anal. Calcd for C23H29NO2: C, 78.59; H, 8.32; N, 3.99. Found: C, 78.30; H, 8.70; N, 3.87.
Example 14 Synthesis of 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoic acid (102) (A61)




Amine (6) was coupled to 4-iodo-methylbenzoate (96) in a tris(dibenzylideneacetone)dipalladium(0) catalytic system employing racemic BINAP to give methyl 4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (100) in 81% purified yield. Methyl ester 100 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (101) in 97% purified yield. The methyl ester of 101 was saponified by refluxing 101 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoic acid (102) in 71% yield.
a. Methyl 4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (100)
To a solution of 6 (1.7092 g, 7.86 mmol), 96 (2.1030 g, 8.03 mmol), CsCO3 (6.24 g, 19.2 mmol), rac-BINAP (0.3836 g, 0.616 mmol) in toluene (9.0 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.3596 g, 0.20 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 3.5% ethyl acetate:hexanes) to give 100 (2.2557 g, 81%) as a crystalline solid, m.p. 132-147° C.: 1H NMR (400 MHz, CDCl3) δ 7.88 (d, J=8.8, 2H), 7.21 (s, 1H), 7.16 (s, 1H), 6.77 (d, J=9.2, 2H), 5.68 (br s, 1H), 3.86 (s, 3H), 2.19 (s, 3H), 1.69 (s, 4H), 1.30 (s, 6H), 1.24 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 167.1, 149.7, 143.7, 141.5, 136.0, 131.4, 129.1, 129.0, 121.3, 119.8, 113.5, 51.5, 35.1, 35.0, 34.0, 33.8, 31.8, 17.6; IR (neat) 3352, 2956, 1687, 1597, 1276 cm−1; ES-MS (M+Na)+ calcd for C23H29NO2Na 374.2096. found 374.2092.
b. Methyl 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (101)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.2646 g, 6.62 mmol). The dispersion of sodium hydride was washed with hexanes (3.7 mL, twice) and dried under vacuum and suspended in 3.8 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 100 (1.018 g, 2.90 mmol) in DMF (11.4 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.36 mL, 4.5 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 2.5% ethyl acetate:hexanes) to give 101 (1.073 g, 97%) as a white crystalline solid, m.p. 104.6-106.0° C.: 1H NMR (400 MHz, CDCl3) δ 7.82 (d, J=9.2, 2H), 7.20 (s, 1H), 7.00 (s, 1H), 6.44 (d, J=8.8, 2H), 3.83 (s, 3H), 3.66 (q, J=7.2, 2H), 2.03 (s, 3H), 1.69 (s, 4H), 1.31 (s, 6H), 1.25 (t, J=6.8, 3H), 1.23 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 167.4, 151.7, 144.4, 143.9, 140.9, 133.1, 131.2, 129.3, 127.1, 116.9, 111.0, 51.3, 45.8, 35.1, 34.9, 34.0, 34.0, 31.9, 31.8, 17.4, 12.4; IR (neat) 2954, 1701, 1602, 1275, 1176 cm−1; ES-MS (M+Na)+ calcd for C25H33NO2Na 402.2409. found 402.2403.
c. 4-(Ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoic acid (102)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 101 (0.5537 g, 1.46 mmol) suspended in methanol (5.0 mL) was added a solution of potassium hydroxide (0.2665 g, 4.75 mmol) in water (0.32 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (76 mL). The precipitate was filtered to give a crude product that was purified by column chromatography (25 mL SiO2, 20% ethyl acetate:hexanes to 50% ethyl acetate:hexanes) to give pure 102 (0.3815 g, 71%) as a white crystalline solid, m.p. 252.4-256.8° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.06 (br s, 1H), 7.68 (d, J=9.2, 2H), 7.28 (s, 1H), 7.02 (s, 1H), 6.40 (d, J=8.8, 2H), 3.62 (br s, 2H), 1.97 (s, 3H), 1.63 (s, 4H), 1.25, (s, 6H), 1.19 (s, 6H), 1.14 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 167.3, 151.1, 144.0, 143.2, 140.7, 132.8, 131.1, 129.1, 126.6, 117.3, 110.7, 45.4, 34.6, 34.4, 33.7, 33.6, 31.6, 31.5, 17.0, 12.2; IR (neat) 2957, 1665, 1597, 1274, 1176 cm−1; ES-MS (M−H)− calcd for C24H30NO2 364.2277. found 364.2268. Anal. Calcd for C24H31NO2: C, 78.86; H, 8.55; N, 3.83. Found: C, 78.87; H, 8.91; N, 3.76.
Example 15 Synthesis of 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoic acid (105) (A62)




Amine (6) was coupled to 2-fluoro-4-iodo-methylbenzoate (2) in a tris(dibenzylideneacetone)-dipalladium(0) catalytic system employing racemic BINAP to give methyl 2-fluoro-4-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (103) in 52% purified yield. Methyl ester 103 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoate (104) in 68% purified yield. The methyl ester of 104 was saponified by refluxing 104 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoic acid (105) in 85% yield.
a. Methyl 2-fluoro-4-((5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (103)
To a solution of 6 (0.8098 g, 3.98 mmol), 2 (1.1254 g, 4.02 mmol), CsCO3 (3.12 g, 9.58 mmol), rac-BINAP (0.1901 g, 0.305 mmol) in toluene (4.5 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.1783 g, 0.19 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 3.7% ethyl acetate:hexanes) to give 103 (0.7449 g, 52%) as a crystalline solid, m.p. 121.8-136.7° C.: 1H NMR (400 MHz, CDCl3) δ 7.80 (t, J=8.4, 1H), 7.27 (d, J=8.4, 1H), 7.08 (d, J=2.4, 1H), 6.96 (dd, J=8.4, 2.4, 1H), 6.65 (dd, J=8.8, 2.4, 1H), 6.62 (dd, J=12.4, 2.4, 1H), 5.95 (br s, 1H), 3.87 (s, 3H), 1.69 (s, 4H), 1.28 (s, 6H), 1.27 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 165.2, 164.9, 164.8, 162.6, 150.8, 150.7, 146.4, 141.2, 137.0, 133.6, 133.5, 127.6, 119.8, 119.4, 110.0, 108.0, 107.9, 101.4, 101.1, 51.7, 34.9, 34.9, 34.3, 33.9, 31.8, 31.7; IR (neat) 3344, 2956, 1703, 1620, 1601, 1273 cm−1; ES-MS (M+Na)+ calcd for C22H26FNO2Na 378.1845. found 378.1848.
b. Methyl 4-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoate (104)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.1656 g, 4.14 mmol). The dispersion of sodium hydride was washed with hexanes (2.2 mL, twice) and dried under vacuum and suspended in 2.3 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 103 (0.6515 g, 1.83 mmol) in DMF (6.9 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.22 mL, 2.8 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 104 (0.4809 g, 68%) as a crystalline solid, m.p. 108.8-113.1° C.: 1H NMR (400 MHz, CDCl3) 7.72 (t, J=9.2, 1H), 7.33 (d, J=8.4, 1H), 7.08 (d, J=2.0, 1H), 6.91 (dd, J=8.4, 2.4, 1H), 6.38 (dd, J=9.2, 2.4, 1H), 6.29 (dd, J=15.2, 2.4, 1H), 3.85 (s, 3H), 3.71 (q, J=7.2, 2H), 1.70 (s, 4H), 1.31 (s, 6H), 1.25 (s, 6H), 1.23 (t, J=7.2, 3H); 13C NMR (100.6 MHz, CDCl3) δ 165.2, 165.1, 162.5, 153.6, 153.5, 146.8, 143.4, 142.2, 133.1, 133.0, 128.1, 125.5, 124.5, 108.5, 105.5, 100.3, 100.0, 51.5, 46.8, 34.9, 34.9, 34.4, 34.1, 31.8, 31.7, 12.3; IR (neat) 2954, 1712, 1621, 1266 cm−1; ES-MS (M+Na)+ calcd for C24H30FNO2Na 406.2158. found 406.2161.
c. 4-(Ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoic acid (105)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 104 (0.4057 g, 1.06 mmol) suspended in methanol (3.5 mL) was added a solution of potassium hydroxide (0.1979 g, 3.53 mmol) in water (0.24 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (60 mL). The precipitate was filtered to give a crude product (0.3768 g, 96%) that was purified by column chromatography (25 mL SiO2, 20% ethyl acetate:hexanes to 50% ethyl acetate:hexanes) to give pure 105 (0.3342 g, 85%) as a white crystalline solid, m.p. 252.4-256.8° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.35 (br s, 1H), 7.62 (t, J=9.2, 1H), 7.41 (d, J=8.4, 1H), 7.14 (d, J=2.4, 1H), 6.97 (dd, J=8.4, 2.4, 2H), 6.38 (dd, J=9.2, 2.4, 1H), 6.32 (dd, J=14.8, 2.4, 1H), 3.71 (q, J=7.2, 2H), 1.65 (s, 4H), 1.26, (s, 6H), 1.21 (s, 6H), 1.12 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 164.9, 164.8, 164.5, 161.9, 153.0 152.9, 146.4, 142.7, 141.9, 133.2, 128.1, 125.1, 124.5, 108.6, 105.7, 105.6, 99.7, 99.4, 46.3, 34.5, 34.4, 34.0, 33.7, 31.5, 31.4, 12.0; IR (neat) 2964, 1668, 1617, 1282 cm−1; ES-MS (M−H)− calcd for C23H27FNO2 368.2026. found 368.2043. Anal. Calcd for C23H28FNO2: C, 74.77; H, 7.64; N, 3.79; F, 5.14. Found: C, 74.42; H, 8.00; N, 3.64; F, 4.1.
Example 16 Synthesis of 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoic acid (108) (A60)




Amine (6) was coupled to 2-fluoro-4-iodo-methylbenzoate (2) in a tris(dibenzylideneacetone)-dipalladium(0) catalytic system employing racemic BINAP to give methyl 2-fluoro-4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (106) in 65% purified yield. Methyl ester 106 was treated with sodium hydride in DMF followed by ethyl iodide to give methyl 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoate (107) in 91% purified yield. The methyl ester of 107 was saponified by refluxing 107 in methanol with an aqueous solution of potassium hydroxide followed by acidification with 20% hydrochloric acid to 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoic acid (108) in 84% yield.
a. Methyl 2-fluoro-4-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)benzoate (106)
To a solution of 6 (1.7074 g, 7.86 mmol), 2 (2.2494 g, 8.03 mmol), CsCO3 (6.24 g, 19.2 mmol), rac-BINAP (0.3824 g, 0.614 mmol) in toluene (9.0 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.3593 g, 0.39 mmol). The solution was sparged with nitrogen for 5 min., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125-120° C.) for 22 h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes) to give 106 (1.9009 g, 65%) as a crystalline solid, m.p. 159.7-165.1° C.: 1H NMR (400 MHz, CDCl3) δ 7.79 (t, J=8.8, 1H), 7.17 (d, J=3.6, 1H), 6.51 (dd, J=8.8, 2.0, 1H), 6.38 (dd, J=13.6, 2.0 1H), 5.74 (br s, 1H), 3.87 (s, 3H), 2.17 (s, 3H), 1.68 (s, 4H), 1.29 (s, 6H), 1.24 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 165.3, 165.0, 164.9, 162.7, 151.9, 151.8, 143.9, 142.6, 135.2, 133.6, 133.5, 129.9, 129.1, 122.5, 109.6, 109.5, 107.5, 107.4, 100.9, 100.6, 51.7, 35.0. 34.9, 34.0, 33.9, 31.8; IR (neat) 3346, 2922, 1698, 1606, 1264 cm−1; ES-MS (M+Na)+ calcd for C23H28FNO2Na 392.2002. found 392.2003.
b. Methyl 4-(ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoate (107)
To a flame-dried, 100 mL round-bottomed flask equipped with a magnetic stir bar was added a 60% dispersion of sodium hydride in mineral oil (0.2628 g, 6.72 mmol). The dispersion of sodium hydride was washed with hexanes (3.7 mL, twice) and dried under vacuum and suspended in 3.8 mL of DMF under nitrogen. To this solution of sodium hydride in DMF was added a solution of 106 (1.1174 g, 3.02 mmol) in DMF (11.4 mL), and the reaction was stirred for 15 min., and then ethyl iodide (0.36 mL, 4.5 mmol) was added, and the reaction was stirred for 1 h. The reaction was poured into water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 6% ethyl acetate:hexanes) to give 107 (1.0951 g, 91%) as a crystalline solid, m.p. 90.3-91.5° C.: 1H NMR (400 MHz, CDCl3) 7.72 (t, J=8.8, 1H), 7.20 (s, 1H), 6.97 (s, 1H), 6.21 (d, J=8.4, 1H), 6.11 (d, J=14.8, 1H), 3.84 (s, 3H), 3.63 (br s, 2H), 2.03 (s, 3H), 1.69 (s, 4H), 1.30 (s, 6H), 1.24 (t, J=7.2, 3H), 1.23 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 165.3, 165.2, 165.1, 162.8, 153.6, 153.5, 144.6, 144.3, 140.3, 133.3, 133.2, 132.9, 129.4, 126.9, 107.3, 105.0, 104.9, 99.0, 98.7, 51.5, 46.1, 35.0, 34.9, 34.0, 34.0, 31.8, 17.3, 12.4; IR (neat) 2954, 1715, 1694, 1622, 1296, 1273 cm−1; GC-MS (M+Na)+ calcd for C25H32FNO2Na 420.2315. found 420.2321.
c. 4-(Ethyl(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)-2-fluorobenzoic acid (108)
To a 100 mL round-bottomed flask equipped with a stir bar and charged with methyl ester 107 (0.5320 g, 1.34 mmol) suspended in methanol (4.7 mL) was added a solution of potassium hydroxide (0.2379 g, 4.24 mmol) in water (0.29 mL). This reaction was stirred at reflux in an oil bath at 87° C. for 1 h. The reaction was then cooled to r.t. and acidified with 20% HCl (70 mL). The precipitate was filtered to give a crude product that was purified by column chromatography (25 mL SiO2, 20% ethyl acetate:hexanes to 50% ethyl acetate:hexanes) to give pure 108 (0.4335 g, 84%) as a white crystalline solid, m.p. 241.4-243.8° C.: 1H NMR (400 MHz, d6-DMSO) δ 12.29 (br s, 1H), 7.62 (t, J=8.8, 1H), 7.31 (s, 1H), 7.03 (s, 1H), 6.19-6.11 (m, 2H), 3.61 (br s, 2H), 1.98 (s, 3H), 1.63 (s, 4H), 1.26, (s, 6H), 1.20 (s, 6H), 1.13 (t, J=7.2, 3H); 13C NMR (100.6 MHz, d6-DMSO) δ 164.9, 164.9, 164.7, 162.2, 153.0, 152.9, 144.1, 143.7, 140.0, 133.4, 132.6, 129.3, 126.5, 107.3, 105.1, 105.0, 98.3, 98.0, 45.6, 34.5, 34.4, 33.7, 31.6, 31.5, 16.9, 12.1; IR (neat) 2922, 1670, 1606, 1285 cm−1; ES-MS (M−H)− calcd for C24H29FNO2 382.2182. found 382.2170. Anal. Calcd for C24H30FNO2: C, 75.16; H, 7.88; N, 3.65; F, 4.95. Found: C, 75.28; H, 8.45; N, 3.61; F, 4.3.
Example 17 Synthesis of 4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)vinyl)benzenesulfonic acid (172) (Compounds A52 and A53)




Commercially available potassium 4-carboxybenzenesulfonate (166) was refluxed in thionyl chloride and thereby converted to 4-(chlorosulfonyl)benzoyl chloride (167). Benzoyl chloride (167) was mixed with 1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene (4), and when aluminum chloride was added to the mixture, the Friedel-Crafts acylation provided 4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl)benzene-1-sulfonyl chloride (168) in 86% yield. Sulfonyl chloride (168) was converted to 4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl)benzenesulfonic acid (169) in 56% yield by treatment of 168 with sodium hydroxide in acetone followed by acidification with 20% HCl. Sulfonyl chloride 168 was also observed to react with 2-methylpropanol in acetone and triethylamine to give isobutyl 4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl)benzenesulfonate (170) in 87% yield. When the isobutyl sulfonate ester 70 was treated with a solution of triphenylphosphine methylide, isobutyl 4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)vinyl)benzenesulfonate (171) was produced in 48.9% yield. The vinyl sulfonate (171) was refluxed with KOH in methanol and then treated with 20% HCl to give 4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)vinyl)benzenesulfonic acid (172) in 80% yield.
a. 4-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl)benzene-1-sulfonyl chloride (168)
A 100 mL round bottom flask was charged with potassium 4-carboxybenzenesulfonate (166) (1.61 g, 6.70 mmol), a few drops of DMF were added followed by thionyl chloride (11.0 mL, 151 mmol), and a reflux condenser fitted with a drying tube was attached and the heterogeneous reaction mixture was refluxed in an oil bath at 85° C. After 40 minutes at reflux, the reaction solution was homogeneous. After 1 h at reflux, the reaction solution was cooled to room temperature, excess thionyl chloride was removed in vacuo, benzene (20 mL) was added and this was removed in vacuo, and the crude product (167) was dried on high vacuum for 10 min. and used without further purification. To a 50 mL two-neck round bottom flask charged with 1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene (4) (1.47 g, 7.26 mmol) was added a solution of (167) in 15 mL DCM followed by AlCl3 (2.27 g, 17.0 mmol) in small portions. Upon the addition of aluminum chloride, the reaction solution boiled, and when the addition of aluminum chloride was complete, the reaction was refluxed in an oil bath at 55° C. for 15 min., cooled to rt and poured into an ice solution (25 mL) and 20% HCl (7 mL) was added. The layers were separated and the aqueous layer was extracted with ethyl acetate (50 mL, twice). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo to yield a crude product that was purified by column chromatography (150 mL SiO2, 5% ethyl acetate:hexanes) to give (168) (2.3592 g, 86%) as a yellow-brown crystalline solid, m.p. 111-114° C.: 1H NMR (400 MHz, CDCl3) δ 8.13 (d, J=8.8, 2H), 8.01 (d, J=8.4, 2H), 7.24-7.26 (m, 2H), 2.37 (s, 3H), 1.70 (s, 4H), 1.32 (s, 6H), 1.21 (s, 6H); 13C NMR (100.6 MHz, CDCl3) δ 196.0, 149.2, 146.7, 144.0, 142.2, 135.0, 133.6, 131.0, 129.8, 128.7, 126.9, 34.8, 34.7, 34.4, 33.9, 31.7, 31.5, 20.1; IR (neat) 2928, 1661, 1374, 1256, 1186, 1174 cm−1.
b. 4-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl)benzenesulfonic acid (169)
To a 20 dram vial charged with (168) (0.5621 g, 1.39 mmol) was added acetone (2.0 mL) and the vial was gently heated until the solution was homogeneous. To this solution of (168) in acetone was added a solution of potassium hydroxide (0.213 g, 3.80 mmol) in water (0.25 mL). The reaction was stirred and gently warmed to keep the solution homogeneous for 30 min. at which point the reaction was quenched with 20% HCl (20 mL) and extracted with ethyl acetate (50 mL, thrice). The combined organic layers were washed with water (50 mL) and then brine (50 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to give a crude produce that was purified by column chromatography (25 mL SiO2, 10% methanol:ethyl acetate) to give (169) (0.300 g, 56%) as a white crystalline solid, decomp. >200° C.: 1H NMR (400 MHz, d6-DMSO) δ 7.75 (dd, J=6.4, 1.6, 2H), 7.66 (dd, J=6.4, 1.6, 2H), 7.30 (s, 1H), 7.21 (s, 1H), 2.21 (s, 3H), 1.65 (s, 4H), 1.28 (s, 6H), 1.18 (s, 6H); 13C NMR (100.6 MHz, d6-DMSO) δ 197.1, 152.3, 147.1, 141.4, 137.3, 135.3, 133.2, 129.4, 128.9, 127.0, 125.8, 34.4, 34.3, 33.9, 33.5, 31.4, 31.3, 19.3; IR (neat) 2925, 1673, 1191, 1123, 1038 cm−1; ES-MS (M−H)− calcd for C22H25SO4 385.1474. found 385.1472. Anal. Calcd for C22H26O4S.(H2O)2: C, 62.54; H, 7.16; S, 7.59. Found: C, 61.75; H, 6.76; S, 7.25.
c. Isobutyl 4-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonyl)benzenesulfonate (170)
To a 20 dram vial charged with 68 (1.0064 g, 2.49 mmol) was added acetone (2.5 mL) and the solution was gently heated until it became homogenous. 2-Methyl-1-propanol (0.45 mL, 4.87 mmol) was added followed by triethylamine (0.40 mL, 2.87 mmol), and the reaction was gently warmed and stirred for 1 h. TLC showed complete conversion, and the reaction solution was loaded directly onto a silica gel column (150 mL SiO2, 2% ethyl acetate:hexanes) to give (170) (0.9568 g, 87%) as a white crystalline solid, m.p. 168-170° C.: 1H NMR (400 MHz, CDCl3) δ 8.00 (d, J=8.8, 2H), 7.94 (d, J=9.2, 2H), 7.24 (s, 1H), 7.22 (s, 1H), 3.87 (d, J=6.4, 2H), 2.35 (s, 3H), 1.95 (hept, J=6.8, 1H), 1.90 (s, 4H), 1.69 (s, 6H), 1.19 (s, 6H), 0.91 (d, J=6.8, 6H); 13C NMR (100.6 MHz, CDCl3) δ 196.7, 148.9, 142.8, 142.1, 139.4, 134.8, 134.0, 130.5, 129.6, 128.6, 127.7, 34.8, 34.7, 34.4, 33.9, 31.6, 31.5, 28.0, 20.1, 18.5; IR (neat) 2924, 1673, 1652, 1188 cm−1; ES-MS (M+Na)+ calcd for C26H34SO4Na 465.2076. found 465.2069.
d. Isobutyl 4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)vinyl)benzenesulfonate (171)
To a flame-dried 100 mL round-bottomed flask was added THF (2.0 mL), isopropylamine (0.70 mL, 8.6 mmol) followed by 1.6 M n-butyllithium in hexanes (2.80 mL, 4.5 mmol) and the solution was stirred for 30 minutes. To this solution was added methyltriphenylphosphonium bromide (1.19 g, 3.33 mmol), and the reaction was stirred for 20 minutes and then added to a 20 dram vial containing a solution of (170) (0.89 g, 2.01 mmol) in THF (2.0 mL). The reaction was stirred for 1 h, then poured into water (50 mL) and extracted with ethyl acetate (50 mL, twice). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give a crude product that was run through a silica gel column (150 mL SiO2, 1% ethyl acetate:hexanes) to give (171) with a 9 mol % contamination of triphenylphosphine oxide (0.8874 g, 48.9%) as a colorless, crystalline solid, m.p. 92-94° C.: 1H NMR (400 MHz, CDCl3) δ 7.83 (dd, J=6.8, 2.0, 2H), 7.44 (dd, J=6.8, 2.0, 2H), 7.12 (s, 1H), 7.09 (s, 1H), 5.84 (d, J=1.2, 1H), 5.39 (d, J=1.2, 1H), 3.81 (d, J=6.4, 1H) 1.97 (s, 3H), 1.95 (hept, J=6.8, 1H), 1.70 (s, 4H), 1.31 (s, 6H), 1.28 (s, 6H), 0.89 (d, J=6.4, 6H); IR (neat) 2960, 1673, 1190, 1039 cm−1; ES-MS (M+Na)+ calcd for C27H36SO3Na 463.2283. found 463.2280.
e. 4-(1-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)vinyl)benzenesulfonic acid (172)
To a 100 mL round-bottomed flask equipped with a magnetic stir bar and charged with (171) (0.2046 g, 0.464 mmol) in methanol (3.0 mL) was added a solution of potassium hydroxide (0.0902 g, 1.61 mmol) in water (0.18 mL). The flask was fitted with a water condenser, and heated to reflux in an oil bath at 85° C. for 2 h. The reaction was cooled to r.t. and 20% HCl (30 mL) was added. The resulting solution was extracted with ethyl acetate (50 mL, twice), and the combined organic layers were dried over sodium sulfate, filtered, concentrated in vacuo and purified by column chromatography (25 mL SiO2, 10% methanol:ethyl acetate) to give (172) (0.1436 g, 80%) as a white crystalline solid, decomp. >280° C.: 1H NMR (400 MHz, d6-DMSO) δ 7.55 (d, J=8.4, 2H), 7.18 (d, J=8.4, 2H), 7.13 (s, 1H), 7.05 (s, 1H), 5.79 (d, J=1.2, 1H), 5.14 (d, J=1.2, 1H), 1.91 (s, 3H), 1.64 (s, 4H), 1.26 (s, 6H), 1.22 (s, 6H); 13C NMR (100.6 MHz, d6-DMSO) δ 148.5, 147.4, 143.5, 141.7, 140.2, 138.2, 132.1, 127.7, 127.2, 125.7, 125.4, 115.4, 34.7, 34.6, 33.6, 33.4, 31.7, 31.6, 19.5; IR (neat) 2961, 1455, 1179, 1043, 1008, 845, 669 cm−1; ES-MS (M−H)− calcd for C23H27SO3 383.1681. found 383.1667. Anal. Calcd for C23H28O4S.(H2O)2: C, 65.68; H, 7.67; S, 7.62. Found: C, 63.94; H, 7.35; S, 7.15.
All publications, patents, and patent documents (including International Patent Application Publication Number WO2011/103321 and in International Patent Application Publication Number WO2013/040227) are incorporated by reference herein, as though individually incorporated by reference. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.

## Claims

1. A compound of formulae II:



wherein:
X is N, Y is CH and Z is N;
X is N, Y is CH and Z is CH;
X is N, Y is N and Z is CH;
X is CH, Y is CH and Z is CH;
R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br; wherein the ring containing X, Y, and Z is optionally substituted on carbon with one or more groups independently selected from halo;
or a salt thereof
provided the compound is not:

2. The compound of claim 1 which is a compound of formulae IIa, IIb, or IIc:



wherein:
R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;
or a salt thereof.

3. The compound of claim 1 which is a compound of formulae IIa or IIc:



wherein:
R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;
or a salt thereof.

4. The compound of claim 1 which is a compound of formulae IIc:



wherein:
R2 is H or methyl; and
R3 is ethyl that is optionally substituted with one or more groups independently selected from F, Cl, and Br;
or a salt thereof.

5. A compound selected from:












or a salt thereof.

6. A compound selected from:



or a salt thereof.

7. The compound,



or a salt thereof.

8. A compound selected from the group consisting of:






or a salt thereof.

9. A compound selected from the group consisting of:



or a salt thereof.