ANTIBACTERIAL AGENTS

Compounds of formula (I) have antibacterial activity:

wherein R represents hydrogen or 1, 2 or 3 optional substituents; W is ═C(R1)— or ═N—; R1 is hydrogen or an optional substituent and R2 is hydrogen, methyl, or fluorine; or R1 and R2 taken together are —CH2—, —CH2CH2—, —O—, or, in either orientation, —O—CH2— or —OCH2CH2—; R3 is a radical of formula -(Alk1)m-(Z)p-(Alk2)n-Q wherein m, p and n are independently 0 or 1, provided that at least one of m, p and n is 1, Z is —O—, —S—, —S(O)—, —S(O2)—, —NH—, —N(CH3)—, —N(CH2CH3)—, —C(═O)—, —O—(C═O)—, —C(═O)—O—, or an optionally substituted divalent monocyclic carbocyclic or heterocyclic radical having 3 to 6 ring atoms; or an optionally substituted divalent bicyclic heterocyclic radical having 5 to 10 ring atoms; Alk1 and Alk2 are optionally substituted C1-C6 alkylene, C2-C6 alkenylene, or C2-C6 alkynylene radicals, which may optionally terminate with or be interrupted by —O—, —S—, —S(O)—, —S(O2)—, —NH—, —N(CH3)—, or —N(CH2CH3)—; and Q is hydrogen, halogen, nitrile, or hydroxyl or an optionally substituted monocyclic carbocyclic or heterocyclic radical having 3 to 6 ring atoms; or an optionally substituted bicyclic heterocyclic radical having 5 to 10 ring atoms.

This invention relates to the use of a class of substituted benzamides and pyridylamides as antibacterial agents, to novel members of that class per se, and to pharmaceutical compositions comprising such compounds.

BACKGROUND TO THE INVENTION

Many classes of antibacterial agents are known, including the penicillins and cephalosporins, tetracyclines, sulfonamides, monobactams, fluoroquinolones and quinolones, aminoglycosides, glycopeptides, macrolides, polymyxins, lincosamides, trimethoprim and chloramphenicol. The fundamental mechanisms of action of these antibacterial classes vary.

Bacterial resistance to many known antibacterials is a growing problem. Accordingly there is a continuing need in the art for alternative antibacterial agents, especially those that have mechanisms of action fundamentally different from the known classes.

Amongst the Gram-positive pathogens, such as staphylococci, streptococci, mycobacteria and enterococci, resistant strains have evolved/arisen which make them particularly difficult to eradicate. Examples of such strains are methicillin resistant Staphylococcus aureus (MRSA), methicillin resistant coagulase negative staphylococci (MRCNS), penicillin resistant Streptococcus pneumoniae and multiply resistant Enterococcus faecium. In view of the rapid emergence of multidrug-resistant bacteria, the development of antibacterial agents with novel modes of action that are effective against the growing number of resistant bacteria, particularly the vancomycin resistant enterococci and beta-lactam antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus, is of utmost importance.

Cell division has been of considerable interest to the pharmaceutical industry as a target because it comprises a group of well conserved target proteins that are all essential for the viability of a wide range of bacteria, and their activities are completely different from those of the proteins involved in cell division of mammalian cells. A number of compounds that act on components of the cell division machinery have been described (Ohashi, Y. et al. J. Bacteriol. 181, 1348-1351 (1999),

BRIEF DESCRIPTION OF THE INVENTION

This invention is based on the finding that a class of substituted benzamides and pyridylamides has antibacterial activity as evidenced by inhibition of bacterial growth by members of that class. The compounds exhibit activity against strains of Gram-positive bacteria, such as staphylococci, clostridia, listeria and bacilli, for example Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus saprophyticus, Bacillus subtilis, Bacillus anthracis and Bacillus cereus. Whilst the invention is not limited by any particular hypothesis as to the mechanism of action of the compounds, it is presently believed that such activity is mediated by the compounds inhibiting cell division through binding to FtsZ.

DETAILED DESCRIPTION OF THE INVENTION

According to a broad aspect of the invention, there is provided the use of a compound which is a substituted benzamide or pyridylamide of formula (I) or a salt, hydrate, or solvate thereof, in the manufacture of a medicament for use in treating bacterial infection:

In other broad aspects, the invention includes

Some members of the class of compounds defined by formula (I) above are believed novel in their own right, and the invention includes all such novel members of the class.

Thus the invention also includes novel compounds which are substituted benzamides or pyridylamides of formula (IC) and salts, hydrates or solvates thereof:

wherein W is ═C(R1)— or ═N—; R1 is hydrogen or an optional substituent and R2 is hydrogen, methyl, or fluoro; or R1 and R2 taken together are —CH2—, —CH2CH2—, —O— or, in either orientation, —O—CH2— or —OCH2CH2—; R4 and R5 are independently fluoro or chloro, or one of R4 and R5 is hydrogen while the other is fluoro or chloro; and R3 is a radical selected from those of the following formulae A-H, in which any vacant ring position is optionally substituted:

wherein Q is hydrogen, halogen, nitrile, or hydroxyl; or an optionally substituted monocyclic carbocyclic or heterocyclic radical having 3 to 6 ring atoms; or an optionally substituted bicyclic heterocyclic radical having 5 to 10 ring atoms.

The invention also includes novel pyridylamide compounds of formula (ID) and salts, hydrates or solvates thereof:

wherein R2 is hydrogen, methyl, or fluoro; and R3 is as defined in relation to formula (IC).

Terminology

As used herein, the term “(Ca-Cb)alkyl” wherein a and b are integers refers to a straight or branched chain alkyl radical having from a to b carbon atoms. Thus when a is 1 and b is 6, for example, the term includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl and n-hexyl.

As used herein the term “divalent (Ca-Cb)alkylene radical” wherein a and b are integers refers to a saturated hydrocarbon chain having from a to b carbon atoms and two unsatisfied valences. The term includes, for example, methylene, ethylene, n-propylene and n-butylene.

As used herein the term “(Ca-Cb)alkenyl” wherein a and b are integers refers to a straight or branched chain alkenyl moiety having from a to b carbon atoms having at least one double bond of either E or Z stereochemistry where applicable. The term includes, for example, vinyl, allyl, 1- and 2-butenyl and 2-methyl-2-propenyl.

As used herein the term “divalent (Ca-Cb)alkenylene radical” means a hydrocarbon chain having from a to b carbon atoms, at least one double bond, and two unsatisfied valences.

As used herein the term “Ca-Cb alkynyl” wherein a and b are integers refers to straight chain or branched chain hydrocarbon groups having from a to b carbon atoms and having in addition at least one triple bond. This term would include for example, ethynyl, 1-propynyl, 1- and 2-butynyl, 2-methyl-2-propynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl and 5-hexynyl.

As used herein the term “divalent (Ca-Cb)alkynylene radical” wherein a and b are integers refers to a divalent hydrocarbon chain having from a to b carbon atoms, and at least one triple bond. The term includes, for example, —C≡C—, —C≡C—CH2—, and —CH2—C≡CH—.

As used herein the term “cycloalkyl” refers to a monocyclic or bridged monocyclic saturated carbocyclic radical having from 3-8 carbon atoms and includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and bicyclo[2.2.1]hept-1-yl.

As used herein the unqualified term “aryl” refers to a mono- or bi-cyclic carbocyclic aromatic radical. Illustrative of such radicals are phenyl and naphthyl.

As used herein the unqualified term “heteroaryl” refers to a mono-, or bi-cyclic aromatic radical containing one or more heteroatoms selected from S, N and O, and includes radicals having two such monocyclic rings, or one such monocyclic ring and one monocyclic aryl ring, which are fused or directly linked by a covalent bond. Illustrative of such radicals are thienyl, benzthienyl, furyl, benzfuryl, pyrrolyl, imidazolyl, benzimidazolyl, thiazolyl, benzthiazolyl, thiazolopyridinyl, isothiazolyl, benzisothiazolyl, pyrazolyl, oxazolyl, benzoxazolyl, isoxazolyl, benzisoxazolyl, isothiazolyl, triazolyl, benztriazolyl, thiadiazolyl, oxadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyridazinyl, triazinyl, indolyl and indazolyl.

Unless otherwise specified in the context in which it occurs, the term “substituted” as applied to any moiety herein means substituted with up to four compatible substituents, each of which independently may be, for example, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, hydroxy, hydroxy(C1-C6)alkyl, mercapto, mercapto(C1-C6)alkyl, (C1-C6)alkylthio, halo (including fluoro, bromo and chloro), fully or partially fluorinated (C1-C3)alkyl, (C1-C3)alkoxy or (C1-C3)alkylthio such as trifluoromethyl, trifluoromethoxy, and trifluoromethylthio, nitro, nitrile (—CN), oxo (═O), phenyl, phenoxy, monocyclic heteroaryl or heteroaryloxy with 5 or 6 ring atoms,

As used herein the term “salt” includes base addition, acid addition and quaternary salts. Compounds of the invention which are acidic can form salts, including pharmaceutically acceptable salts, with bases such as alkali metal hydroxides, e.g. sodium and potassium hydroxides; alkaline earth metal hydroxides e.g. calcium, barium and magnesium hydroxides; with organic bases e.g. N-methyl-D-glucamine, choline tris(hydroxymethyl)amino-methane, L-arginine, L-lysine, N-ethyl piperidine, dibenzylamine and the like. Those compounds (I) which are basic can form salts, including pharmaceutically acceptable salts with inorganic acids, e.g. with hydrohalic acids such as hydrochloric or hydrobromic acids, sulphuric acid, nitric acid or phosphoric acid and the like, and with organic acids e.g. with acetic, tartaric, succinic, fumaric, maleic, malic, salicylic, citric, methanesulphonic, p-toluenesulphonic, benzoic, benzenesulfonic, glutamic, lactic, and mandelic acids and the like.

For a review on suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, Weinheim, Germany, 2002).

The term ‘solvate’ is used herein to describe a molecular complex comprising the compound of the invention and a stoichiometric amount of one or more pharmaceutically acceptable solvent molecules, for example, ethanol. The term ‘hydrate’ is employed when said solvent is water.

Compounds of the invention which contain one or more actual or potential chiral centres, because of the presence of asymmetric carbon atoms, can exist as a number of enantiomers or diastereoisomers with R or S stereochemistry at each chiral centre. The invention includes all such enantiomers and diastereoisomers and mixtures thereof.

Aspects of the Invention

A particular subclass of compounds for antibacterial use in accordance with the invention is concerned consists of those of formula (IA)

wherein R4 and R5 are independently fluoro or chloro, or one of R4 and R5 is hydrogen while the other is fluoro or chloro, and R1, R2 and R3 are as defined with reference to formula (I) above.

Another particular subclass of compounds for antibacterial use in accordance with the invention is concerned consists of those of formula (IB)

wherein R2 and R3 are as defined with reference to formula (I) above.

In a narrow subclass of compounds for antibacterial use in accordance with the invention is concerned, including those of formula (IA) above, R1 and R2 are hydrogen; and in the compounds of formula (IB) above R2 is hydrogen.

In the radical R3, p may be 0, and m and/or n may be 1. Alternatively, p may be 1, and Z may be an optionally substituted carbocyclic or heteroaryl radical having 3 to 6 ring atoms or an optionally substituted bicyclic carbocyclic or heteroaryl radical having 5 to 10 ring atoms, which is linked to the -(Alk1)m- part of R3 and to the -(Alk2)n-Q part of R3 via ring carbon or nitrogen atoms. Examples of divalent radicals Z in this embodiment include those selected from the following, in either orientation:

In another alternative embodiment p is 1, and Z is an optionally substituted monocyclic non-aromatic carbocyclic or heterocyclic radical having 3 to 6 ring atoms or an optionally substituted bicyclic non-aromatic carbocyclic or heterocyclic having 5 to 10 ring atoms, which is linked to the -(Alk1)m- part of R3 and to the -(Alk2)n-Q part of R3 via ring carbon or nitrogen atoms. Examples of Z radicals, which are optionally substituted, in this embodiment include those selected from the following, in either orientation:

In the compounds with which the invention is concerned, and in any of the subclasses or embodiments of such compounds discussed above, Q may be hydrogen. However Q may also be a radical selected from any of the divalent Z radicals specifically identified above but with one of the unsatisfied valencies thereof satisfied with hydrogen or an optional substituent.

In the compounds with which the invention is concerned, and in any of the subclasses or embodiments of such compounds discussed above n and/or m may be 0.

In all compounds and classes of compounds with which the invention is concerned, it is typical that the radical R3, when fully extended, does not exceed the length of an unbranched saturated hydrocarbon chain of 14 carbon atoms, ie does not exceed about 16 Angstroms. For example, that length may be equivalent to that of an unbranched saturated hydrocarbon chain of from 6 to 12, or 9 to 12 carbon atoms, ie from about 6 to about 14, and from about 10 to about 14 Angstroms respectively.

In the compounds with which the invention is concerned, Alk1 and Alk2, when present, may be, for example, optionally substituted straight chain C1-C6 alkylene, C2-C6 alkenylene, or C2-C6 alkynylene radicals, each of which may optionally terminate with or be interrupted by —O—, —S—, —S(O)—, —S(O2)—, —NH—, —N(CH3)—, or —N(CH2CH3)—, —C(═O)—, —O—(C═O)—, —C(═O)—O—.

Compounds of formula (IC) per se, and salts, hydrates or solvates thereof constitute a distinct aspect of the invention:

In compounds (IC) it is currently preferred that W be ═CH— and R2 be hydrogen.

In compounds (IC) Q in radical R3 may be hydrogen or optionally substituted phenyl.

Compounds of formula (ID) per se, and salts, hydrates or solvates thereof also constitute a distinct aspect of the invention:

wherein R2 is hydrogen, methyl, or fluoro; and R3 is as defined in relation to formula (IC).

Specific examples of compounds with which the invention is concerned include those of the Examples herein.

There are multiple synthetic strategies for the synthesis of the compounds (I) with which the present invention is concerned, but all rely on known chemistry, known to the synthetic organic chemist. Thus, compounds according to formula (I) can be synthesised according to procedures described in the standard literature and are well-known to the one skilled in the art. Typical literature sources are “Advanced Organic Chemistry”, 4th Edition (Wiley), J March, “Comprehensive Organic Transformation”, 2nd Edition (Wiley), R. C. Larock, “Handbook of Heterocyclic Chemistry”, 2nd Edition (Pergamon), A. R. Katritzky), review articles such as found in “Synthesis”, “Acc. Chem. Res.”, “Chem. Rev”, or primary literature sources identified by standard literature searches online or from secondary sources such as “Chemical Abstracts” or “Beilstein”.

Compounds (I) may be prepared, for example, by introduction of the radical -(Alk1)m-(Z)p-(Alk2)n-Q onto the hydroxyl group of a compound (II)

Further details of the synthetic approaches and schemes for the preparation of the intermediate (II) are given in the Examples herein.

As mentioned above, the compounds with which the invention are concerned are antibacterially active, since they inhibit bacterial growth. They are therefore of use in the treatment of bacterial infection in humans and non-human animals e.g. other mammals, birds and fish. The compounds include those which inhibit growth of Gram-positive organisms such as Bacillus subtilis and Staphylococcus aureus and some show activity against certain Gram-negative organisms also.

It will be understood that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing therapy. As is required in the pharmaceutical art, safe and permitted doses will be determined by clinical trial, but daily dosages can vary within wide limits and will be adjusted to the individual requirements in each particular case. Typically, however, the dosage adopted for each route of administration when a compound is administered alone to adult humans is 0.0001 to 150 mg/kg body weight. Such a dosage may be given, for example, from 1 to 5 times daily. For intravenous injection a suitable daily dose is from 0.0001 to 150 mg/kg body weight. A daily dosage can be administered as a single dosage or according to a divided dose schedule.

The compounds with which the invention is concerned may be prepared for administration by any route consistent with their pharmacokinetic properties, such as oral, topical, or sterile parenteral solutions or suspensions. The orally administrable compositions may be in the form of tablets, capsules, powders, granules, lozenges, liquid or gel preparations. Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinyl-pyrrolidone; fillers for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricant, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants for example potato starch, or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in normal pharmaceutical practice. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example sorbitol, syrup, methyl cellulose, glucose syrup, gelatin hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters such as glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p-hydroxybenzoate or sorbic acid, and if desired conventional flavouring or colouring agents. For topical application to the skin, the drug may be made up into a cream, lotion or ointment. Cream or ointment formulations which may be used for the drug are conventional formulations well known in the art, for example as described in standard textbooks of pharmaceutics such as the British Pharmacopoeia.

For topical application to the eye, the drug may be made up into a solution or suspension in a suitable sterile aqueous or non aqueous vehicle. Additives, for instance buffers such as sodium metabisulphite or disodium edeate; preservatives including bactericidal and fungicidal agents such as phenyl mercuric acetate or nitrate, benzalkonium chloride or chlorhexidine, and thickening agents such as hypromellose may also be included.

The active ingredient may also be administered parenterally in a sterile medium, either subcutaneously, or intravenously, or intramuscularly, or intrasternally, or by infusion techniques, in the form of sterile injectable aqueous or oleaginous suspensions. Depending on the vehicle and concentration used, the drug can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as a local anaesthetic, preservative and buffering agents can be dissolved in the vehicle.

Since the compounds with which the invention is concerned are antibacterially active and inhibit bacterial growth, they are also of use in treating bacterial contamination of a substrate, such as hospital instruments or work surfaces. In order to treat a contaminated substrate, the compounds may be applied to the site of such contamination in an amount sufficient to inhibit bacterial growth.

The following examples illustrate the synthesis of compounds with which the invention is concerned.

Analytical Method

The analytical methods used to characterise compounds included HPLC-MS and 1H NMR.

Time (mins)
% A
% B

Time (mins)
% A
% B

Time (mins)
% A
% B

Time (mins)
% A
% B

UV Max
Variable

Injection volume
Variable

Mobile Phase
A - Acetonitrile B - 0.1% Formic acid

Time
A
B

UV Max
286.0 nm

Injection volume
Variable

Mobile Phase
A - Acetonitrile B - 0.1% Formic acid

Time
A
B

UV Max
variable

Sample preparation
Methanol

Injection volume
Variable

Time (mins)
% A
% B

Time (mins)
% A
% B

1H NMR spectra were consistent with the required structures.

Melting points were measured on a Stuart Scientific SMP10 apparatus and are uncorrected.

Yields given are not optimised.

EXPERIMENTAL PROCEDURES

3-Hydroxybenzoic acid (110.5 g, 0.8 mol, 1 equiv.) was suspended in toluene (500 ml) and thionyl chloride (88.0 ml, 1.2 mol, 1.5 equiv.) was added slowly, at room temperature. The solution was heated to reflux where it was maintained for 5 h. After this time, the reaction was cooled to room temperature and concentrated in vacuo. The residue was dissolved in tetrahydrofuran (300 ml) and cooled in an ice-methanol bath. Concentrated aqueous ammonia solution (˜300 ml) was added slowly, dropwise and the reaction mixture was warmed slowly to room temperature where it was stirred for 16 h. The reaction mixture was concentrated in vacuo and the resulting solid was suspended in water and filtered. The collected solid was washed with additional water (×3) and then dried in vacuo to give 3-hydroxybenzamide as an off-white solid (79.9 g, 72.8%) mp 167-168° C. HPLC-MS (method 1): m/z 136 [M−H]−. Rt=1.21 min. 1H NMR (d6-DMSO) δ=9.53 (s, 1H), 7.78 (s, 1H), 7.30-7.15 (m, 4H), 6.88 (d, J=8 Hz, 1H).

NB 1: The final purification step was dependent on the nature of the R group. Other purification methods used in course of the library synthesis were:

NB 2: In the case of water soluble target compounds, the aqueous phase was concentrated in vacuo and then washed with MeOH. The methanolic fractions were concentrated in vacuo and the crude product purified by preparative HPLC.

Examples 2 to 44 were synthesised according to Method B, scheme 2

Table of names of product compounds; Examples 2-44:

Example
Compound name

NB 2: In some cases unsupported triphenyl phosphine was used. In the case of phenols containing fluorine atoms, no product could be detected when using polymer-supported triphenyl phosphine and so the reactions were performed with triphenyl phosphine.

Examples 46 to 61 were synthesised according to Method C, scheme 3

Table of names of product compounds; Examples 46-61:

Example
Compound name

(Method D) K2CO3 (1.38 g, 10 mmol, 1 equiv.) was added to a suspension of 3-hydroxybenzamide (1.37 g, 10 mmol, 1 equiv.) in CH3CN (100 ml). The mixture stirred for 10 min at room temperature, before 1,6-dibromo-hexane (9.76 g, 40 mmol, 4 equiv.) was added. The resulting mixture was stirred at 60° C. for 16 h. After this time, the reaction was cooled to room temperature, any undissolved solids were filtered off and the filtrate evaporated under reduced pressure to dryness. The residue was taken-up in EtOAc and water. The organic phase was separated and washed consecutively with K2CO3 solution, water and brine. Dried with MgSO4 and evaporated under reduced pressure to a small volume. The precipitant solid was filtered and washed with EtOAc/pentane, to give the desired compound as a white solid (2.0 g, 67%), mp 115-117° C. HPLC-MS (method 1): m/z 300 [M]+, 302 [M+2H]+, Rt=4.08 min.

A mixture of 3-[(6-bromohexyl)oxy]benzenecarboxamide (2.10 g, 7 mmol, 1 equiv.) and triphenylphosphine (1.93 g, 7.35 mmol, 1.05 equiv.) in CH3CN (30 ml) was heated under reflux for 72 h. The solvent was evaporated under reduced pressure and the residue was triturated with dry Et2O until it solidified. The solid was filtered and dried in vacuo to give the desired compound as a white solid (4.0 g, 100%). HPLC-MS (method 1): m/z 482 [M-Br]+, Rt=3.65 min.

(Method E) To a stirred suspension of 6-[3-(aminocarbonyl)phenoxy]hexyl (triphenyl) phosphonium bromide (2.0 g, 3.55 mmol, 1.2 equiv.) in anhydrous toluene (28 ml) was added a solution of potassium bis(trimethylsilyl)amide (0.5M; 7.1 ml, 3.55 mmol, 1.2 equiv.) in toluene, slowly, dropwise over a period of 15 min at 0° C., under N2. The dark orange solution was stirred for another 20 min at 0° C. and cool-d to −78° C., when thiophene-3-carboxaldehyde was instantly added, and the temperature was left to rise—from −78° C. to r.t. The light yellow mixture was stirred at r.t. for 16 h. The reaction mixture was quenched with saturated aqueous NH4Cl (20 ml) and the solvent was evaporated under reduced pressure. The residue was taken-up in CH2Cl2 and H2O, the organic phase was separated, washed with brine and dried (Na2SO4). The solved was evaporated under reduced pressure and the residue was purified by column chromatography on silica eluting with EtOAc/hexane (10%-50% gradient) to give the desired compound as an off-white solid (300 mg, 35%), mp 71-73° C. By 1H NMR analysis it consisted of a mixture of Z:E (90:10). HPLC-MS (method 1): m/z 316 [M+H]+, Rt=4.62 min.

(Method F) Lithium acetylide ethylenediamine complex (305 mg, 3.3 mmol, 1.1 equiv.) was placed in a three-neck flask, degassed, flushed with N2 and suspended in DMSO (2 ml). To the stirred suspension a solution of 3-[(7-bromoheptyl)oxy]benzenecarboxamide (943 mg, 3 mmol, 1 equiv.) in DMSO (2 ml), was added, slowly, dropwise, at r.t., under N2. The reaction mixture was stirred at r.t. for 16 h. After that time it was diluted with 1N HCl solution and extracted with EtOAc (×3). The combined organic extracts were washed with brine, dried (Na2SO4) and evaporated to dryness under reduced pressure. The crude product was purified by column chromatography on silica eluting with EtOAc/hexane 20%, to give the desired compound as a white solid (100 mg, 13%), mp 82-83° C. HPLC-MS (method 1): m/z 260 [M+H]+, Rt=4.26 min.

(Method G) A solution of commercially available 2-[(8-bromooctyl)oxy]tetrahydro-2H-pyran (1.0 g, 3.4 mmol, 1 equiv.) in DMSO (5 ml), was added, slowly, dropwise, at r.t., under N2, to a stirred suspension of lithium acetylide ethylenediamine complex (350 mg, 3.8 mmol, 1.1 equiv.) in DMSO (5 ml). The reaction mixture was stirred at r.t. for 18 h and diluted with n-pentane (50 ml). The organic phase was washed with 1N HCl solution (2×20 ml) and water (2×20 ml), dried (Na2SO4) and evaporated to dryness under reduced pressure. The residue (colourless liquid, 570 mg, yield 70%) was dissolved in 95% EtOH (20 ml) together with p-toluenesulfonic acid (150 mg) and the mixture was heated under reflux for 2.5 h. After being cooled, the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica eluting with EtOAc/hexane (10%-30% gradient), to give the desired compound as a colourless oil (240 mg, overall yield 48%).

(Method H) Boron tribromide solution (1.0 M in CH2Cl2, 23.6 ml, 23.6 mmol, 2 equiv.) was added slowly, dropwise to stirred solution of 2-fluoro-5-methoxybenzenecarboxamide (2.0 g, 11.8 mmol, 1 equiv.) in CH2Cl2 (60 ml), at r.t., under N2. The reaction mixture was stirred at r.t. for 48 h. The solvent was removed under reduced pressure, the residue was dissolved in water (120 ml) and extracted with EtOAc (4×100 ml). The combined organic extracts were washed with water (2×100 ml), dried (Na2SO4) and filtered through a pad of silica gel. The filtrate was evaporated to dryness under reduced pressure, to give the desired compound as a grey solid (1.50 g, 82%).

Examples 70-72 were synthesised from 2-fluoro-5-hydroxybenzenecarboxamide according to Method B, scheme 2 and Examples 73-75 were synthesised from 2-fluoro-5-hydroxybenzenecarboxamide according to Method C, scheme 3.

Table of names of product compounds; Examples 70-75:

Example
Compound name

Synthesised from 6-chloro-2-fluoro-3-methoxybenzenecarboxamide according to Method H. Yield 90%.

Synthesised from commercially available 2-chloro-6-fluoro-3-methoxybenzenecarboxamide, according to Method H. Yield 78%.

Examples 81-83 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method B, scheme 2. Examples 84-88 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method C, scheme 3.

Table of names of product compounds; Examples 81-88:

Example
Compound name

Methyl 2-[3-(aminocarbonyl)-2,4-difluorophenoxy]acetate (7 mmol, 1 equiv.) was added to a solution of NaOH (1 g, 25 mmol, 3.6 equiv.) in water (20 ml) and isopropyl alcohol (5 ml). The mixture was stirred under reflux for 1.5 h, diluted with water (40 ml) and extracted with CH2Cl2 (40 ml). The aqueous phase was acidified to pH 1 with conc. HCl solution. The precipitant solid was filtered and dried in vacuo to give the desired compound (130 mg, 8%), mp 152-153° C. HPLC-MS (method 1): m/z 312 [M−H+2CH3CN]−, Rt=0.91 min.

n-Bromohexane (0.077 ml, 0.55 mmol, 1.05 equiv.) was added to a suspension of 2-[3-(aminocarbonyl)-2,4-difluorophenoxy]acetic acid (120 mg, 0.52 mmol, 1 equiv.) and K2CO3 (215 mg, 1.56 mmol, 3 equiv.) in DMF (3 ml) and the mixture was stirred at 70° C. for 1.5 h. After cooling at r.t., the mixture was poured into water (25 ml) and the precipitant solid was filtered and washed with water (2×20 ml). After drying, the crude solid was triturated by stirring in hexane (10 ml), filtered and washed with hexane (3×10 ml), to give the desired compound as a white solid (99 mg, 60%), mp 108° C. HPLC-MS: m/z 316 [M+H]+, Rt=4.09 min.

Synthesised from commercially available 2-[(8-bromohexyl)oxy]tetrahydro-2H-pyran according to Method G. Overall yield 55%, colourless oil.

Chloroacetyl chloride (0.16 ml, 2.0 mmol, 1 equiv.) was added to a stirred solution of 7-Octyn-1-ol (300 mg, 2.4 mmol, 1.2 equiv.) in CH2Cl2 (6 m-) at −5° C. The reaction mixture was allowed to warm-up to r.t., were it was stirred for 4 h. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica eluting with EtOAc/hexane (10%) to give the desired compound as a pale yellow liquid (450 mg, 100%).

A solution of diethyl zinc (1.1 M in toluene, 1.84 ml, 2.02 mmol, 1 equiv.) was added to a solution of example 52 (500 mg, 2.02 mmol, 1 equiv.) in dry toluene (1 ml), at r.t., under N2. Diiodomethane (0.244 ml, 3.03 mmol, 1.5 equiv.) was added slowly, dropwise and the reaction mixture was stirred at r.t. for 5 days. The mixture was diluted with water (40 ml) and extracted with CH2Cl2 (4×40 ml). The combined organic extracts were dried (MgSO4) and the solvents were removed under reduced pressure. By HPLC-MS, the crude residue consisted of starting material (80%) and desired product (20%). The reaction was repeated in the same way, in toluene (15 ml) using diethyl zinc (1.1 M in toluene, 6.1 ml, 6.6 mmol, 3.3 equiv.) and diiodomethane (0.244 ml, 3.03 mmol, 1.5 equiv.). The reaction mixture was stirred at 50° C. for 5 days, diluted with water (80 ml) and extracted with CH2Cl2 (4×50 ml). The combined organic extracts were dried (MgSO4) and the solvents were removed under reduced pressure. The residue was triturated by stirring in pentane (15 ml) and the precipitant solid was filtered and rinsed with pentane to give 196 mg of a white compound, mp 104-105° C. By HPLC-MS it consisted of starting material (65%) and the desired product (35%). HPLC-MS (method 1): m/z 303 [M+H+CH3CN]+, Rt=4.83 min.

Toluenesulfonyl chloride (410 mg, 2.15 mmol, 1.5 equiv.) and triethylamine (0.40 ml, 2.88 mmol, 2 equiv.) were added to a solution of 3-[(9-hydroxynonyl)oxy]benzenecarboxamide (400 mg, 1.43 mmol, 1 equiv.) in CH2Cl2 (4 ml) and the reaction mixture was stirred at r.t. for 6 days. Saturated NaHCO3 solution (40 ml) was added and the mixture was extracted with CH2Cl2 (3×30 ml). The combined organic extracts were dried (MgSO4) and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica eluting with CH3OH/CH2Cl2 (2%), to give the desired compound as white solid (428 mg, 69%), mp 78-80° C. HPLC-MS (method 1): m/z 434 [M+H]+, Rt=4.90 min.

Sodium cyanide (60 mg, 1.22 mmol, 1.3 equiv.) was added to a solution of 9-[3-(aminocarbonyl)phenoxy]nonyl 4-methylbenzenesulfonate (407 mg, 0.94 mmol, 1 equiv.) in water (10 ml) and 95% EtOH (8 ml), and the reaction mixture was stirred at 75° C. for 2 days. After cooling at r.t., the mixture was diluted with water (10 ml) and extracted with CH2Cl2 (3×10 ml). The combined organic extracts were dried (MgSO4) and the solvent was removed under reduced pressure. The crude residue was purified by column chromatography on silica eluting with EtOAc/hexane (50%), to give the desired compound as white solid (57 mg, 21%), mp 96-97° C. HPLC-MS (method 1): m/z 289 [M+H]+, Rt=4.16 min.

A solution of 2-(nonyloxy)isonicotinonitrile (250 mg, 1.0 mmol, 1 equiv.) and sodium methoxide (10 mg, 0.1 mmol, 0.1 equiv.) in dry CH3OH (10 ml) was stirred at r.t. for 2.5 h. A solution of lithium hydroxide (24 mg, 1.0 mmol, 1 equiv.) in water (1 ml) was added and the reaction mixture was heated under reflux for 3.5 h. After cooling at r.t., the mixture was poured into water (40 ml). The precipitant solid was filtered and dried in vacuo at 50° C., to give the desired compound as a white solid (60 mg, 23%), mp 108-110° C. HPLC-MS (method 1): m/z 265 [M+H]+, Rt=5.08 min.

Bromine (1.9 ml, 37.28 mmol, 1.05 equiv.) was added slowly, dropwise, to a solution of 1-heptene (5 ml, 35.5 mmol, 1 equiv.) in CCl4 (7 ml) cool-d at −10° C., under N2. The reaction mixture was stirred at r.t. for 16 h. The solvent was removed by evaporation under reduced pressure. The residue was partitioned between CH2Cl2 (200 ml) and 10% aqueous sodium metabisulfate solution (200 ml). The organic phase was separated, washed with brine and dried (Na2SO4). It was evaporated under reduced pressure to dryness, to give the desired compound as a colourless oil (8.94 g, 98%).

1,2-Dibromoheptane (5.11 g, 19.8 mmol, 1.1 equiv.) was added to a mixture of di-hydroxy benzonitrile (2.43 g, 18 mmol, 1 equiv.) and K2CO3 (12.4 g, 90 mmol, 5 equiv.) in CH3CN (100 ml). The reaction mixture was heated under reflux for 4 days. After cooling to r.t., the solvent was removed under reduced pressure; the residue was diluted with water (200 ml) and extracted with EtOAc (3×150 ml). The combined organic phases were washed with brine, dried (Na2SO4) and evaporated under reduced pressure to dryness. The residue was purified by column chromatography on silica eluting with EtOAc/hexane (5%-10% gradient) to give the desired compound as a colourless oil (390 mg, 9%); mixture of two regio-isomers. HPLC-MS (method 1): m/z 230 [M−H]−, Rt=5.28 min.

A mixture of regio-isomers 3-pentyl-2,3-dihydro-1,4-benzodioxine-6-carbonitrile and 2-pentyl-2,3-dihydro-1,4-benzodioxine-6-carbonitrile (50 mg, 0.22 mmol) was stirred vigorously in conc. H2SO4 (0.5 ml) and warmed to 40° C. Water (82 mg) was added dropwise and the mixture was stirred for 45 min at 40° C. The mixture was cooled at −5° C., and ice (25 ml) was added quickly, with vigorous stirring. The mixture stirred at r.t. for two more hours. The precipitant solid was filtered, washed with water and dried in vacuo, at 40° C. It was purified on preparative TLC plate (Analtech, 2 mm, 20×20) eluting with methyl-tert-butyl-ether, to give the desired compound as a white solid (50 mg, 93%), HPLC-MS (method 1): m/z 291 [M+H+CH3CN]+, Rt=4.14 min.

The compounds of Examples 96-99, 101-116, 117, 119, 122, 124, 128-134, 137-139, 142, 144-154, 156-159 and 161-163 were synthesized according to the following general procedure: To a solution of reactant (A) in anhydrous DMF (B), 2,6-difluoro-3-hydroxybenzamide (C) and potassium carbonate (D) were added. The reaction mixture was stirred at room temperature or 25° C. under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400μ) using ethyl acetate/hexane as the eluent to provide the product compound.

TABLE E

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

benzoic acid methyl ester

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction scheme

hexane ratio

Reaction

scheme

hexane ratio

Reaction scheme

hexane ratio

Example 167: Synthesis of 3-Fluoro-5-hexyloxy benzamide

Example 168: Synthesis of 3-(Pyrazol-1-ylmethoxy)-benzamide

N-Bromosuccinimide (2.13 g, 12 mmol) and subsequently α,α′-azoisobutyronitrile (16 mg, 0.1 mmol) were added to a solution of 3,5-lutidine (1.14 ml, 10 mmol) in CCl4 (40 ml). The reaction mixture was stirred at reflux for 2 hrs. After cooling, succinimide was removed by filtration and the filtrate was evaporated to smaller volume (10 ml). To this filtrate, a mixture of 3-hydroxybenzenecarboxamide (550 mg, 4 mmol) and K2CO3 (830 mg, 6 mmol) in DMF (5 ml) was added and the new reaction mixture was stirred at 60° C. for 24 h. After diluting with CH2Cl2 (100 ml), the solution was washed with Na2CO3 solution (40 ml) and water (40 ml), dried (Na2SO4) and evaporated to dryness, under reduced pressure. The brown oil residue was extracted by trituration with Et2O (2×10 ml), and from the Et2O extracts, the precipitant solid was filtered and washed with pentane, to give 70 mg (7.2% yield) of the desired product. Mp 152-154° C., HPLC-MS: m/z 243 [M+H]+, Rt=2.28 min.

To a stirred solution of 3-hydroxybenzylalcohol (1.0 g, 8 mmol, 1 equiv.) in 6.4N KOH solution (1.86 ml, 12 mmol, 1.5 equiv.) at r.t., ice (4 g) was added followed by acetic anhydride (0.95 ml, 10 mmol, 1.25 equiv.). The reaction mixture was stirred at r.t. for 3 h. Water (50 ml) was added and the mixture was stirred for 30 min, before extracting with CH2Cl2 (2×50 ml). The combined organic extracts were washed with brine (50 ml), dried (Na2SO4) and evaporated to dryness, under reduced pressure. The clear oil residue was purified by column chromatography on silica, eluted with EtOAc/hexane (1:2), to give the desired product as a clear oil (714 mg, 54% yield). HPLC-MS (method 1): m/z 165 [M−H]−. Rt=2.52 min.

A solution of K2CO3 (500 mg, 3.62 mmol, 5.75 equiv.) in water (5 ml) was added to a solution of 3-[3-(aminocarbonyl)phenoxy]methylphenyl acetate (180 mg, 0.63 mmol, 1 equiv.) and the mixture was stirred at r.t., under N2, for 3 h; The mixture was acidified with 10% HCl solution to pH 1, and was extracted with EtOAc (2×30 ml). The combined organic extracts were washed with water (30 ml), dried (Na2SO4) and evaporated to dryness under reduced pressure, to give a clear oil residue which, after trituration with Et2O, solidified to a white solid (70 mg, 46% yield). Mp 122-123° C., HPLC-MS (method 1): m/z 244 [M+H]+. Rt=2.92 min.

A solution of sodium hydride (60% in mineral oil, 600 mg, 15.0 mmol, 3 equiv.) in hexanol (10 ml) was stirred at r.t. for 2 h. 2,3-Dichloro-isonicotinic acid (960 mg, 5.0 mmol, 1 equiv.) was added and the reaction mixture was stirred at 100° C. for 16 h. The mixture was diluted with water (100 ml) and pentane (300 ml), and the two phases were separated. The aqueous phase was neutralised with 1N HCl solution to pH 6.0 and extracted with EtOAc (3×80 ml). The combined EtOAc extracts were dried (MgSO4) and evaporated under reduced pressure to dryness. The residue was triturated with pentane, cooled at 0° C. and the precipitant solid was filtered, to give 410 mg of a white compound (yield 32%). By 1H-NMR analysis, it consisted of about 80% of the desired product, which was used to the next step without further purification. HPLC-MS: m/z 256 [M−H]−, Rt=2.94 min.

Examples 175-178 were synthesised from 2-fluoro-3-hydroxybenzenecarboxamide. Examples 175, 176 and 178 according to Method B, scheme 2 and Example 177 according to Method C, scheme 3.

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 175-178:

Example
Compound name

A solution of methyl 4-[3-(aminocarbonyl)-2,4-difluorophenoxy]-2-butenoate (1.25 g, 4.61 mmol, 1 equiv.) and NaOH (0.75 g, 18.44 mmol, 4 equiv.) in isopropanol (10 ml) and H2O (20 ml) was heated under reflux for 1 h. After cooling to r.t., the mixture was acidified with conc. HCl to pH 1. The white precipitant solid was filtered and washed with Et2O (50 ml), to give 568 mg, 48% yield, mp 187-188° C., HPLC-MS (method 1): m/z 258 [M+H]+, Rt=0.98 min. By 1H-NMR analysis it was determined to be a mixture of isomeres in a ratio (3:2) E:Z.

The aqueous phase was extracted with Et2O (2×50 ml) and the combined extracts were dried (Na2SO4) and evaporated to dryness under reduced pressure, to give a light orange solid, 418 mg, 35% yield, mp 127-128° C., HPLC-MS (method 1): m/z 258 [M+H]+, Rt=0.99 min. By 1H-NMR analysis it was determined to be a mixture of isomeres in a ratio (3:40) E:Z.

4-[3-(Aminocarbonyl)-2,4-difluorophenoxy]-2-butenoic acid, mixture of isomeres (3:2) E:Z, (526 mg, 2 mmol, 1 equiv.) was dissolved in dry DMF (5 ml). K2CO3 (850 mg, 6 mmol, 3 equiv.) and n-butylbromide (0.23 ml, 2.1 mmol, 1.05 equiv.) were added and the reaction mixture was heated for 70 h at 50° C. and for 1.5 h at r.t. After cooling at r.t., the mixture was diluted with H2O (50 ml) and extracted with EtOAc (3×40 ml). The combined organic extracts were washed with H2O (6×30 ml), dried (MgSO4) and evaporated to dryness under reduced pressure. The oily residue was purified by column chromatography on silica, eluted with CH2Cl2 and MeOH/CH2Cl2 (1%), to give 364 mg, 57% yield, mp<40° C. HPLC-MS (method 1): m/z 314 [M+H]+, Rt=3.88 min. By 1H-NMR analysis it was determined to be a mixture of isomeres in a ratio (5:7) E:Z. When the same reaction was performed on the acid (3:40) E:Z mixture of isomeres, the product obtained was determined to be a mixture of isomeres in a ratio (1:4) E:Z.

Examples 182-197 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide: Examples 182, 190, 192, 193 and 195 according to according to Method B, scheme 2 and Examples 183-189, 191, 194 and 196-197 according to Method C, scheme 3.

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 182-197:

Example
Compound name

Examples 202-207 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method C, scheme 3.

Structure

Structure

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 202-207:

Example
Compound name

Pyridine (0.37 ml, 4.72 mmol, 1.5 equiv.) and subsequently cyanuric fluoride (0.53 ml, 6.3 mmol, 2 equiv.) were added to a stirred solution of commercially available 5-(trifluoromethyl)-1-benzothiophene-2-carboxylic acid (776 mg, 3.15 mmol, 1 equiv.) in CH2Cl2 (16 ml), kept under N2, at −20 to −10° C. Precipitation of cyanuric acid occurred and increased gradually as the reaction proceeded. After the mixture was stirred at −20 to −10° C. for 2 h, ice-cold water was added along with 100 ml CH2Cl2. Undissolved solids were filtered off; from the filtrate, the organic phase was separated and the aqueous layer was extracted once more with CH2Cl2 (50 ml). The combined organic layers were washed with ice-cold water (50 ml), dried (Na2SO4) and concentrated under reduced pressure to a small volume (15 ml). NaBH4 (240 mg, 6.3 mmol, 2 equiv.) was added in one portion, and MeOH (6.5 ml) was then added, dropwise, over 15 min at r.t. The reaction mixture was neutralised with 1N H2SO4, and the organic solvents were evaporated under reduced pressure. The residue was taken-up in EtOAc (80 ml) and water (40 ml); the organic layer was separated, and the aqueous layer was extracted with EtOAc (2×60 ml). The combined organic layers were washed with 1N H2SO4 and brine, dried (Na2SO4) and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica, using EtOAc/hexane (10-20% gradient) as eluent, to give 400 mg (54.6% yield) of the required product as a white solid. HPLC-MS (method 1) gave one peak with Rt=4.02 min, but no ionization.

Examples 209-217 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method B, scheme 2.

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 209-217:

Example
Compound name

Examples 218-221 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide and 5-chloro-2-(chloromethyl)-1,3-benzothiazole according to Method B, scheme 2.

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 218-221:

Example
Compound name

2-[(5-Chloro-1,3-benzothiazol-2-yl)methoxy]isonicotinonitrile (40 mg, 0.13 mmol) was dissolved in conc. H2SO4 (0.36 ml) and the solution was heated at 40° C., under vigorous stirring. Water (50 mg) was added dropwise and the mixture was stirred at 40° C. for 3 h. After cooling at −5° C., crushed ice (25 ml) was added quickly, with vigorous stirring, and the mixture was stirred at r.t. for two more hours. Ammonia solution was added (pH 10) and the precipitant solid was filtered, rinsed with H2O and dried. The brown solid was purified by preparative TLC, eluted with EtOAc, to give 20 mg (47% yield), mp 220-222° C., HPLC-MS (method 1): m/z 320 [M+H]+, Rt=3.76 min.

(Method J) A solution of 4-ethyl-1,3-benzothiazol-2-amine (1.0 g, 5.6 mmol, 1 equiv.) and KOH (7.4 g, 112.2 mmol, 20 equiv.) in 2-methoxy-ethanol (9 ml) and H2O (9 ml), was stirred under N2 and under reflux, for 20 h. After cooling at r.t., the mixture was poured into water (150 ml) and extracted with CH2Cl2 (2×40 ml). The aqueous phase was neutralised with conc. HCl and extracted again with CH2Cl2 (3×70 ml). The combined neutral extracts were washed with water (2×60 ml), dried (Na2SO4) and evaporated to dryness under reduced pressure. The yellow-green semi-solid residue (790 mg) was mixed with 2-chloro-1,1,1-trimethoxy ethane (1.62 g, 10.4 mmol) and the mixture was stirred, under N2, at 60° C., for 4 h. Volatiles were removed by evaporation under reduced pressure and the brown liquid residue was purified by column chromatography on silica, eluted with CH2Cl2/hexane (10% and 50%), to give a yellow liquid (406 mg, 34% yield over two steps). HPLC-MS (method 1): m/z 212 [M+H]+, Rt=5.00 min

Synthesised from commercially available 6-methoxy-1,3-benzothiazol-2-amine according to Method J, scheme 25. It was used crude on the next step.

(Method K) A solution of KOH (15.15 g, 270 mmol, 20 equiv.) in H2O (25 ml) was added to a solution of 4-chloro-1,3-benzothiazol-2-amine (2.5 g, 13.5 mmol, 1 equiv.) in 2-methoxy-ethanol (25 ml) and the reaction mixture was heated under reflux overnight. After cooling at r.t., the mixture was diluted with H2O (200 ml), acidified with 5N HCl solution to pH 4 and extracted with CH2Cl2 (3×150 ml). The combined organic extracts were washed with brine (100 ml), dried (Na2SO4) and concentrated under reduced pressure to dryness, to give 1.5 g (70% yield). From this crude residue, 167 mg (assuming 1.05 mmol), were mixed with 3-(cyanomethoxy)-2,6-difluorobenzenecarboxamide (150 mg, 0.7 mmol) and the mixture was stirred at 120° C., in a pre-heated oil bath, under N2, for 2 h. EtOH (2 ml) was added and the reaction mixture was heated for a further 2 h. After cooling at r.t., the solid was filtered, washed with EtOH and re-crystallised from EtOAc/pentane, to give the desired product as a pale yellow solid, 62 mg (25% yield on second step). HPLC-MS (method 1): m/z 355 [M+H]+, Rt=3.75 min.

N-Bromosuccinimide (4.45 g, 25 mmol, 1.4 equiv.) and subsequently α,α′-azoisobutyronitrile (110 mg, 0.7 mmol, 0.04 equiv.) were added to a solution of 5-bromo-2-methyl-benzothiazole (4.07 g, 17.85 mmol, 1 equiv.) in CCl4 (110 ml). The reaction mixture was stirred at reflux for 24 hrs. After cooling, succinimide was removed by filtration and was rinsed with CCl4 (100 ml). The filtrate was evaporated to dryness under reduced pressure and the orange solid residue was purified by column chromatography on silica, eluted with CH2Cl2/hexane (20%-70% gradient), to give the desired product as a white solid, 2.15 g (39% yield). Mp 116-117, HPLC-MS (method 1): m/z 308 [M+H]+, Rt=4.84 min. The reaction gave also 1.40 g (20% yield) of the by-product 5-bromo-2-dibromomethyl-benzothiazole, as well as 0.89 g (22%) of un-reacted starting material.

Examples 233-241 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method B, scheme 2.

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 233-241:

Example
Compound name

Examples 243-250 were Synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method B, scheme 2.

Structure

Structure
No example

Structure

Structure

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 243-250:

Example
Compound name

To a solution of 4-[5-(chloromethyl)-1,2,4-oxadiazol-3-yl]aniline (950 mg, 4.53 mmol, 1 equiv.), Et3N (0.20 ml, 5.44 mmol, 1.2 equiv.) and dimethylaminopyridine (catalytic), Boc anhydride (1.04 g, 4.75 mmol, 1.05 equiv.) was added portionwise, and the reaction mixture was stirred at r.t. for 3 days. The solvent was evaporated under reduced pressure, the residue was triturated with Et2O and the solid was removed by filtration. The filtrate was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica, eluted with EtOAc/hexane (20%), to give a cream solid, 780 mg (55% yield). About 70% pure by HPLC-MS (method 1): m/z 308 [M−H]−, Rt=4.72 min. It was used without further purification on the next step.

tert-Butyl N-[4-(5-[3-(aminocarbonyl)-2,4-difluorophenoxy]methyl-1,2,4-oxadiazol-3-yl)phenyl]carbamate (300 mg, 0.67 mmol, 1 equiv.) was dissolved in 4N HCl in dioxane (7 ml, 28 mmol, 42 equiv.) and the reaction mixture was stirred at r.t. overnight. Volatiles were removed under reduced pressure, the residue was triturated with dry Et2O and the solid formed was filtered and rinsed with dry Et2O. The crude product (200 mg) was taken-up in EtOH (2 ml) and was triturated with 2N HCl in Et2O solution (0.3 ml) and dry Et2O. The white solid was filtered and washed with dry Et2O, to give 110 mg of the desired product (43% yield). HPLC-MS (method 1): m/z 347 [M+H−HCl]+, Rt=2.98 min.

Examples 252, 254-256 and 258-266 were synthesised from 2,6-difluoro-3-hydroxybenzenecarboxamide according to Method B, scheme 2. Examples 253 and 257 were synthesised from 2,6-difluoro-3-[3-(2-methoxyphenyl)-1,2,4-oxadiazol-5-yl]methoxybenzene carboxamide according to Method L.

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Structure

Table of names of product compounds; Examples 252-266:

Example
Compound name

To a solution of 4-chlorobenzonitrile (10.0 g, 73.0 mmol) in EtOH (250 mL) was added hydroxylamine hydrochloride (5.03 g, 73.0 mmol) and NaOH (2.90 g, 73.0 mmol). The resulting reaction mixture was refluxed for 15 h. After the completion of the reaction (TLC monitoring), the mixture was concentrated, added EtOH and filtered. The filtrate was evaporated in vacuo and used as such for the next step (crude yield 12.0 g, 66%).

Bromoacetyl bromide (1.50 mL, 17.58 mmol) was added to 4-Chloro-N-hydroxy-benzamide (1.0 g, 5.86 mmol) and K2CO3 (3.18 g, 23.44 mmol). The reaction mixture was heated at 100° C. for 15 m. After the completion of the reaction mixture (TLC monitoring), water (100 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 1% EtOAc-Hexane) to get the desired product (0.44 g, 28%) as a white solid.

The compounds of Examples 267-270 were synthesised according to the following general procedure: To a solution of 5-bromomethyl-3-(4-chloro-phenyl)-[1,2,4]oxadiazole (A) in 2 ml of anhydrous DMF was added reactant (B) and potassium carbonate (C). The reaction mixture was stirred at 25° C. for 24 h under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400 M) using ethyl acetate/hexane (45:55) as the eluent to provide the product compound.

TABLE N

Reaction scheme

method

Reaction scheme

method

Reaction scheme

method

Reaction scheme

method

To the solution of 2-Benzyloxy-thioacetamide (3.0 g, 16.57 mmol) in 3 ml of DMF was added 2-Bromo-1-(4-chloro-phenyl)-ethanone (3.0 g, 12.87 mmol). The reaction mixture was heated at 130° C. for 24 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 2% EtOAc-Hexane) to get the desired product (2.0 g, 49%). The corresponding cyano derivative was also prepared by the same general method.

A solution of 2-Benzyloxymethyl-4-(4-chloro-phenyl)-thiazole (2.0 g, 6.34 mmol) in 25 ml of DCM was cooled to −78° C. followed by addition of BBr3 (2.38 ml, 25.3 mmol). The reaction mixture was stirred at 25° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), solution of NaHCO3 (20 mL) was added at 0° C. and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 40% EtOAc-Hexane) to get the desired product (0.8 g, 57%). The corresponding cyano derivative was also prepared by the same general method.

To the solution of [4-(4-Chloro-phenyl)-thiazol-2-yl]-methanol (0.80 g, 3.55 mmol) in 10 ml of toluene was added PBr3 (0.51 ml, 5.33 mmol) and the reaction mixture was heated at 120° C. for 20 min under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.17 g, 17%). The corresponding cyano derivative was also prepared by the same general method.

The compounds of Examples 271-276 were synthesised according to the following general procedure: To a solution of reactant (A) in anhydrous DMF was added reactant (B) and potassium carbonate (C). The reaction mixture was stirred at 25° C. for 24 h under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane as the eluent to provide the product compound.

TABLE O

Reaction scheme

Reaction scheme

Reaction scheme

Reaction scheme

Reaction scheme

Reaction scheme

The mixture of thioacetamide (16.0 g, 213 mmol) and 2-bromo-1-(4-methoxy-phenyl)-ethanone (4.0 g, 17.5 mmol) was heated at 140° C. for 24 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (100 mL) was added and extracted with ethyl acetate (3×100 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 1% EtOAc-Hexane) to get the desired product (2.5 g, 69%).

To the solution 4-(4-Methoxy-phenyl)-2-methyl-thiazole (5.0, 24.3 mmol) in CCl4 (20 mL) was added NBS (7.43 g, 41.74 mmol) and the reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400 M) using 1% ethyl acetate/hexane to give the desired product (3.0 g, 34%).

To a solution of 5-Bromo-2-bromomethyl-4-(4-methoxy-phenyl)-thiazole (0.50 g, 1.37 mmol) in 5 ml of anhydrous DMF was added 2,6-Difluoro-3-hydroxy-benzamide (0.23 g, 1.37 mmol) and potassium carbonate (0.75 g, 5.43 mmol). The reaction mixture was stirred at 25° C. for 24 h under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (30:70) as the eluent to provide the title compound (0.30 g, 48%).

The compounds of Examples 277-287 were synthesised according to the following general procedure: To a solution of 3-[5-bromo-4-(4-methoxy-phenyl)-thiazol-2-ylmethoxy]-2,6-difluoro-benzamide (A) in 5 ml of anhydrous DMF and water (2.5 ml) was added reactant (B) and potassium phosphate (C). The reaction mixture was degassed for 10 minutes followed by addition of dichlorobis(triphenyl phosphine) palladium (II) (D). The reaction mixture was heated at 120° C. for 12 h under the nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (45% EtOAc-Hexane) to get the desired product compound.

TABLE P

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
60-120 M

Reaction scheme

Silica gel
230-400 M

Reaction scheme

Silica gel
230-400 M

To a solution of 3-[5-bromo-4-(4-methoxy-phenyl)-thiazol-2-ylmethoxy]-2,6-difluoro-benzamide (2.0 g, 4.37 mmol) in the 50 ml of acetic acid was added Zn dust (2.0 g). The reaction mixture was heated at 120° C. for 1 h. After the completion of the reaction mixture (TLC monitoring), water (100 mL) was added and pH was adjusted to 8-9 with NaOH solution and extracted with ethyl acetate (3×150 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.8 g, 50%) as a white solid.

The compound was prepared following the general method as described in the preparation of 4-(4-Methoxy-phenyl)-2-methyl-thiazole (Scheme 31).

The compound was prepared following the general method as described in the preparation of 5-Bromo-2-bromomethyl-4-(4-methoxy-phenyl)-thiazole (Scheme 31).

To a solution of 4-Trifluoromethoxybenzonitrile (1.0 g, 5.0 mmol) in EtOH (20 mL) was added hydroxylamine hydrochloride (0.365 g, 5.0 mmol) and NaOH (0.212 g, 5.0 mmol). The resulting reaction mixture was refluxed for 15 h. After the completion of the reaction (TLC monitoring), the mixture was concentrated, added EtOH and filtered. The filtrate was evaporated in vacuo and used as such for the next step (crude yield 12.0 g, 66%).

Bromoacetyl bromide (2.0 mL, 23.12 mmol) was added to trifluoromethoxy-N-hydroxy-benzamide (0.40 g, 5.86 mmol) and K2CO3 (0.87 g, 6.0 mmol). The reaction mixture was heated at 100° C. for 15 min. After the completion of the reaction mixture (TLC monitoring), water (100 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 3% EtOAc-Hexane) to get the desired product (0.25 g, 43%) as a white solid.

To a solution of 1,3 dichloroacetone (0.504 g, 3.90 mmol) in toluene (5 ml) was added 4-methoxy benzamide (0.30 g, 1.90 mmol). The reaction mixture was heated at 120° C. for 1 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified over silica gel (230-400 M, 15% EtOAc-Hexane) to get the desired product (0.37 g, 83%).

A mixture of 3-Chloro-2-butanone (2.1 g, 10.0 mmol) and 4-methoxybenzamide (0.30 g, 1.0 mmol) was heated at 115° C. for 15 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified over silica gel (230-400 M, 20% EtOAc-Hexane) to get the desired product (0.17 g, 42%) as a white solid. The corresponding chloro derivative was also prepared by the same general method.

To the solution of 4-Bromomethyl-2-(4-methoxy-phenyl)-5-methyl-oxazole (0.17 g, 0.80 mmol) in acetonitrile (4.0 mL) was added NBS (7.43 g, 41.74 mmol). The reaction mixture was stirred at 25° C. for 1 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was cooled to 0° C. and 2 ml of water was added. The resulting precipitate was filtered and dried to give the desired product (0.11 g, 46%). The corresponding chloro derivative was also prepared by the same general method.

To a solution of 5-Bromo-3-nitro-pyridin-2-ol (10.0 g, 45.66 mmol) in 70 ml of toluene and 7 ml of DMF was added PBr3 (6.60 ml, 68.49 mmol) and the reaction mixture was heated at 120° C. for 20 min under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (100 mL) was added and extracted with ethyl acetate (3×200 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (10.30 g, 80.03%).

To the solution of 2,5-Dibromo-3-nitro-pyridine (10.30 g, 35.47 mmol) in the 100 ml of ethanol was added SnCl2 (24.0 g, 106.42 mmol) slowly. The reaction mixture was heated at 80° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. Water (250 mL) was added, white solid separated out, then, basified the reaction mixture with NaOH Solution. To this added the 250 ml of ethyl acetate. Filtered it and washed the residue with ethyl acetate, layers are separated, dried (Na2SO4), filtered, concentrated to give the desired product (6.20 g, 67.39%).

To the solution of 2,5-Dibromo-pyridin-3-ylamine (8.6 g, 34.12 mmol) in 50 ml of DCM was added triethylamine (5.3 ml, 37.53 mmol). Cooled the reaction mixture to 0° C. To this added the solution of 2-benzyloxy acetyl chloride (7.45 g, 40.95 mmol) in 35 ml of DCM. The reaction mixture was stirred at 25° C. for 12 hr. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (10:90) as the eluent to provide the title compound (3.2 g, 24.17%).

To the solution of 2-Benzyloxy-N-(2,5-dibromo-pyridin-3-yl)-acetamide (2.5 g, 6.248 mmol) in 30 ml of toluene was added Lawesson's reagent (1.51 g, 3.74 mmol). The reaction mixture was heated at 120° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (5:95) as the eluent to provide the title compound (1.60 g, 76.5%).

A solution of 2-Benzyloxymethyl-5-bromo-thiazolo[5,4-b]pyridine (1.60 g, 4.77 mmol) DCM (15 mL) was cooled to −78° C. followed by addition of BBr3 (2.27 ml, 23.86 mmol). The reaction mixture was stirred at 25° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), solution of NaHCO3 (20 mL) was added at 0° C. and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (2.0 g, Crude yield).

To a solution of 3-(5-bromo-thiazolo[5,4-b]pyridin-2-ylmethoxy)-2,6-difluoro-benzamide (0.15 g, 0.37 mmol) in 5 ml of anhydrous DMF was added allyl tributyltin (0.26 ml, 0.86 mmol) and degassed the reaction mixture for the 10 minutes. Tetrakis(triphenylphosphine) palladium (0) (0.007 g, 0.0056 mmol) was then added and the reaction mixture was heated at 120° C. for 1 h under the nitrogen atmosphere. Then reaction mixture was cooled to room temperature added water (25 mL) and extracted the compound with ethyl acetate. The combined organic layers were dried over anhydrous Na2SO4, and evaporated to dryness under reduced pressure. The compound was purified by column chromatography on silica (100-200 M) using ethyl acetate/Hexane (60:40) as the eluent to provide the title compound (0.10 g, 75%).

To a solution of 3-(5-bromo-thiazolo[5,4-b]pyridin-2-ylmethoxy)-2,6-difluoro-benzamide (0.10 g, 0.24 mmol) in 5 ml of anhydrous DMF was added 1-methyl-2-tributylstannanyl-1H-imidazole (0.120 g, 0.32 mmol) and degassed the reaction mixture for the 10 minutes. Tetrakis(triphenylphosphine) palladium (0) (0.004 g, 0.0037 mmol) was then added and the reaction mixture was heated at 120° C. for 12 h under the nitrogen atmosphere. The reaction mixture was then cooled to room temperature, added water (25 mL) and extracted the compound with ethyl acetate. The combined organic layers were dried over anhydrous Na2SO4, and evaporated to dryness under reduced pressure. The compound was purified by column chromatography on silica (230-400 M) using ethyl acetate/hexane (40:60) as the eluent to provide the title compound as brick red solid (0.020 g, 20%). 1H NMR (DMSO-d6, 400 MHz): δ 3.14 (s, 3H), 5.67 (s, 2H), 7.07 (m, 1H), 7.28-7.37 (m, 2H), 7.87 (m, 2H), 8.28 (s, 1H), 8.53 (s, 1H) and 8.75 (br s, 1H). MS ES+ (402.22), HPLC (method I) Rt=12.05 min.

To a solution of 1,3 dichloroacetone (0.84 g, 6.62 mmol) in toluene (5 ml) was added 4-methylthiobenzamide (0.50 g, 3.31 mmol) and the reaction mixture was heated at 120° C. for 1 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified over silica gel (230-400 M, 15% EtOAc-Hexane) to get the desired product (0.49 g, 67%). The other derivatives were also prepared by the same general method.

To a solution of 1,3 dichloroacetone (0.42 g, 3.26 mmol) in toluene (5 mL) was added 3-hydroxythiobenzamide (0.25 g, 1.63 mmol) and the reaction mixture was heated at 120° C. for 1 h. After completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness, added water and extracted with EtOAc (×3). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 10% EtOAc-Hexane) to get the desired product (0.14 g, 38%).

To a solution of 2-Benzyloxy-acetamide (1.40 g, 8.56 mmol) in 4 ml of DMF was added 2-Bromo-1-(4-chloro-phenyl)-ethanone (2.0 g, 8.56 mmol) and the reaction mixture was heated at 130° C. for 6 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 10% EtOAc-Hexane) to get the desired product (1.1 g, 44%).

A solution of 2-Benzyloxymethyl-4-(4-chloro-phenyl)-oxazole (1.10 g, 3.6 mmol) in 10 ml of DCM was cooled to −78° C. followed by addition of BBr3 (1.76 ml, 18.0 mmol). The reaction mixture was stirred at 25° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), solution of NaHCO3 (20 mL) was added at 0° C. and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.5 g, 49%, crude).

The compounds of Examples 303-310 were synthesised according to the following general procedure: To a solution of reactant (A) in 2 ml of anhydrous DMF was added 2,6-Difluoro-3-hydroxy-benzamide (B) and potassium carbonate (C). The reaction mixture was stirred at 25° C. for 24 h under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (50:50) as the eluent to provide the product compound.

TABLE Q

Reaction scheme

phenol

Reactant scheme

Reactant scheme

Reaction scheme

Prepared as per the method mentioned in Scheme 31.

Prepared as per the method mentioned in Scheme 31.

Prepared as per the method mentioned in Scheme 31.

A mixture of thioacetamide (16.0 g, 213 mmol) and 2-Bromo-1-(4-methoxy-phenyl)-ethanone (4.0 g, 17.5 mmol) was heated at 140° C. for 24 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 1% EtOAc-Hexane) to get the desired product (2.5 g, 69%).

To the solution of 5-Bromo-2-bromomethyl-4-(4-methoxy-phenyl)-thiazole (5.0 g, 24.3 mmol) in the 20 ml of CCl4 was added NBS (4.32 g, 24.3 mmol) and AIBN (0.4 g, 2.43 mmol). The reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400 M) using 1% ethyl acetate/hexane eluent to give the desired product (4.0 g, 58%).

To a solution of 5-Bromo-4-(4-methoxy-phenyl)-2-methyl-thiazole (2.0 g, 7.0 mmol) in 15 ml of pyridine was added CuCN (3.10 g, 35.2 mmol) and the reaction mixture was heated to 150° C. in microwave for 2 h. After the completion of the reaction pH was adjusted to 3-4 with 1 N HCl solution and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 12% EtOAc-Hexane) to get the desired product (1.5 g, 92%) as a white solid.

To a solution of 4-(4-Methoxy-phenyl)-2-methyl-thiazole-5-carbonitrile (0.50 g, 2.1 mmol) in 15 ml of methanol was passed dry HCl gas for 1 h at 0° C. The reaction mixture was stirred at 25° C. for 24 h. After the completion of the reaction mixture (TLC monitoring), The reaction mixture was evaporated to dryness under reduced pressure. Water (50 ml) was added and pH was adjusted to 7-8 with NaHCO3 solution and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.25 g, 44%) as a white solid.

To the solution of 4-(4-Methoxy-phenyl)-2-methyl-thiazole-5-carboxylic acid methyl ester (0.25 g, 0.94 mmol) in the 20 ml of CCl4 was added NBS (0.16 g, 0.94 mmol) and AIBN (0.015 g, 0.094 mmol). The reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400 M) using 10% ethyl acetate/hexane as a eluent to give the desired product (0.078 g, 24%).

To a solution of cyclohexanone (5.0 g, 51 mmol) in the 80 ml of DCM was added pyridine (4.48 ml, 56.0 mmol) and the resulting reaction mixture was cooled to −78° C. To the reaction mixture the solution of triflic anhydride (7.40 ml, 56.0 mmol) in 30 ml of DCM was added over the period of 1 h. Reaction mixture was stirred at 25° C. for 24 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was triturated with n-pentane and decanted the organic layer, dried (Na2SO4), filtered and concentrated to give the desired product (5.0 g, 42%).

To a solution of cyclopentanone (5.0 g, 59 mmol) in the 80 ml of DCM was added pyridine (5.2 ml, 65.0 mmol) and the resulting reaction mixture was cooled to −78° C. To the reaction mixture the solution of triflic anhydride (9.2 ml, 65.0 mmol) in 30 ml of DCM was added over the period of 1 h. Reaction mixture was stirred at 25° C. for 24 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was triturated with n-pentane and decanted the organic layer, dried (Na2SO4), filtered and concentrated to give the desired product (2.4 g, 22%).

Examples 318 to 333

To the solution of ethyl oxamate (10.0 g, 85.30 mmol) in 120 ml of toluene was added Lawesson's reagent (24.15 g, 59.7 mmol) and the reaction mixture was heated at 120° C. for 12 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica (230-400 M) using ethyl acetate/hexane (5:95) as the eluent to provide the title compound (1.8 g, 16%).

To the solution of 2-Bromo-1-(4-trifluoromethyl-phenyl)-ethanone (0.50 g, 0.80 mmol) in 7 ml of ethanol was added ethyl thio-oxamate (0.15 g, 1.14 mmol). The reaction mixture was heated at 80° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was concentrated under reduced pressure, water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 2% EtOAc-Hexane) to get the desired product (0.21 g, 76%). The other derivatives were also prepared by the same general method.

To an ice-cold suspension of LAH (0.056 g, 1.40 mmol) the 8 ml of anhydrous THE was added dropwise a solution of 4-(4-Trifluoromethyl-phenyl)-thiazole-2-carboxylic acid ethyl ester (0.21 g, 0.71 mmol) in the 5 ml of THF. The reaction mixture was stirred at 25° C. for 1 h. After the completion of the reaction mixture (TLC monitoring), cooled the reaction mixture to 0° C. and quenched with 2.5 ml of water followed by the addition of 15% NaOH solution (2 mL) and finally 4 ml of water. The resulting solution was filtered through celite bed and the filtrate was concentrated under reduced pressure. Water (50 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to give the desired product (0.13 g, 70%). The other derivatives were also prepared by the same general method.

To the solution of [4-(4-Trifluoromethyl-phenyl)-thiazol-2-yl]-methanol (0.13 g, 0.50 mmol) in 2 ml of toluene was added PBr3 (0.072 ml, 0.752 mmol) and the reaction mixture was heated at 120° C. for 20 min under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 1% EtOAc-Hexane) to get the desired product (0.04 g, 25%). The other derivatives were also prepared by the same general method.

To a Solution of 4-chloro-3-nitrobenzoic acid (5.0 g, 24.81 mmol) in 50 ml of methanol was added H2SO4 (2 ml, 37.02 mmol) and the reaction mixture was heated at 70° C. for 5 h. After completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. Water (50 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was, dried (Na2SO4), filtered and concentrated to give the desired product (5.04 g, 94%).

To a solution of 4-Chloro-3-nitro-benzoic acid methyl ester (5.0 g, 23.19 mmol) in 100 ml of ethanol was added SnCl2.2H2O (26.0 g, 115.96 mmol) and the reaction mixture was heated at 80° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. Water (100 mL) was added, basified the reaction mixture with NaOH solution and extracted with hot EtOAc (3×250 mL). The combined organics was dried over Na2SO4, filtered and concentrated to give the desired product (3.0 g, 69%).

A solution of carbonic acid monobenzyl ester (3.50 g, 21.0 mmol) in the 50 ml of DCM and 0.50 ml of DMF was cooled to −78° C. followed by addition of oxalyl chloride (11.79 ml, 105 mmol). The resulting reaction mixture was stirred at room temperature for 1 h. After the completion of the reaction mixture (TLC monitoring), concentrated it to give 2-benzyloxyacetyl chloride (3.0 g, 96%). To an ice cold solution of 3-amino-4-chloro-benzoic acid methyl ester in 10 ml of DCM was added triethylamine (2.47 ml, 17.78 mmol) followed by addition of 2-benzyloxyacetyl chloride (3.0 g, 17.78 mmol) in 10 ml of DCM. The reaction mixture was stirred at 25° C. for 12 hr. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (5:95) as the eluent to provide the title compound (1.70 g, 31%).

To the solution of 3-(2-Benzyloxy-acetylamino)-4-chloro-benzoic acid methyl ester (1.70 g, 5.10 mmol) in 20 ml of toluene was added Lawesson's reagent (1.03 g, 2.50 mmol) and the reaction mixture was heated at 120° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (5:95) as the eluent to provide the title compound (1.20 g, 67%).

To a solution of 3-(2-Benzyloxy-thioacetylamino)-4-chloro-benzoic acid methyl ester (1.20 g, 3.40 mmol) in the 8 ml of NMP was added NaH (0.12 g, 5.10 mmol) portion wise. The reaction mixture was heated at 160° C. for 3 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was poured into 150 ml of ice-cold water and extracted with ethyl acetate (3×150 mL). The combined organics was dried (Na2SO4), filtered and concentrated to give the desired product. (1.07 g, 56%).

A solution of 2-Benzyloxymethyl-benzothiazole-6-carboxylic acid methyl ester (0.10 g, 0.32 mmol) in 2 ml of DCM was cooled to −78° C. followed by addition of BBr3 (0.06 ml, 0.64 mmol). The reaction mixture was stirred at 25° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), solution of NaHCO3 (20 mL) was added at 0° C. and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.08 g, Crude yield).

To a solution of 2-Hydroxymethyl-benzothiazole-6-carboxylic acid methyl ester (0.08 g, 0.40 mmol) in 5 ml of toluene and 1 ml of DMF was added PBr3 (0.06 ml, 0.60 mmol). The reaction mixture was heated at 120° C. for 20 min under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.044 g, 36%).

To a solution of 3,4 Dihydroxy benzonitrile (5.0 g, 37.0 mmol) in 20 ml of DMF was added dibromomethane (19.25 g, 110.0 mmol) and potassium carbonate (25.50 g, 184.90 mmol). The reaction mixture was heated at 120° C. for 2 h under the nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), reaction mixture was cooled to room temperature. Water (50 ml) was added to the reaction mixture and extracted the compound with ethyl acetate (3×100 mL). The combined organic layers were dried over anhydrous Na2SO4, and evaporated to dryness under reduced pressure to give the title compound as yellow solid (5.16 g, 94.8%).

To a solution of Benzo[1,3]dioxole-5-carbonitrile (5.0 g, 33.9 mmol) in EtOH (100 mL) was added hydroxylamine hydrochloride (4.68 g, 67.90 mmol) and NaOH (2.71 g, 67.9 mmol). The resulting reaction mixture was refluxed for 12 h. After the completion of the reaction (TLC monitoring), the mixture was concentrated, added EtOH and filtered. The filtrate was evaporated under reduced pressure and used as such for the next step (crude yield 4.8 g, 78.68%).

Bromoacetyl bromide (0.22 g, 1.10 mmol) was added to N-Hydroxy-benzo[1,3]dioxole-5-carboxamidine (0.40 g, 0.55 mmol) and K2CO3 (0.38 g, 0.78 mmol). The reaction mixture was heated at 100° C. for 15 min. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 5% EtOAc-Hexane) to get the desired product (0.05 g, 31%).

To an ice-cold solution of 4-methoxy-thiobenzamide (0.50 g, 2.98 mmol) in ethanol (25 ml) was added triethylamine (0.41 ml, 2.98 mmol) followed by dropwise addition of ethyl bromopyruvate (0.56 ml, 4.40 mmol). The reaction mixture was heated at 65° C. for 12 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure, water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 10% EtOAc-Hexane) to get the desired product (0.38 g, 48%).

To an ice-cold suspension of LAH (0.08 g, 2.07 mmol) in 10 ml of anhydrous THE was added a solution of 2-(4-Methoxy-phenyl)-thiazole-4-carboxylic acid ethyl ester (0.26 g, 0.98 mmol) in 5 ml of THF. The reaction mixture was heated up to 60° C. for 1 h. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was cooled to 0° C., water (2.0 ml) was added followed by the addition of 15% NaOH solution (2 mL) and finally 4 ml of water. The resulting solution was filtered through celite bed and concentrated under reduced pressure; water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to give the desired product (0.14 g, 64%).

To a solution of [2-(4-Methoxy-phenyl)-thiazol-4-yl]-methanol (0.12 g, 0.50 mmol) in 3 ml of toluene was added PBr3 (0.078 ml, 0.813 mmol) and the reaction mixture was heated at 120° C. for 20 min under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.13 g, 84%).

Propionic anhydride (0.75 mL, 5.79 mmol) was added to 4-Chloro-N-hydroxy-benzamide (0.50 g, 2.89 mmol) and K2CO3 (2.0 g, 14.48 mmol). The reaction mixture was heated at 100° C. for 30 min. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was cooled to 0° C., added water (25 mL) and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (60-120 M, 5% EtOAc-Hexane) to get the desired product (0.29 g, 48%).

To a solution of 3-(4-Chloro-phenyl)-5-ethyl-[1,2,4]oxadiazole (0.29 g, 1.38 mmol) in CCl4 (10 mL) was added NBS (0.24 g, 1.38 mmol) and AIBN (0.02 g, 0.0001 mmol). The reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400 M) using 1% ethyl acetate/hexane as eluent to give the desired product (0.12 g, 30%).

To a solution of (5-Methyl-2-phenyl-2H-[1,2,3]triazol-4-yl)-methanol (0.25 g, 1.30 mmol) in 10 ml of toluene was added PBr3 (0.53 g, 1.90 mmol) and the reaction mixture was heated at 120° C. for 20 min under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.30 g, 90%) as a yellow solid.

To a solution of 2-bromothiazole (1.0 g, 6.09 mmol) in 4 ml of pyridine was added CuCN (1.09 g, 12.19 mmol). The reaction mixture was heated to 150° C. for 3 h. After the completion of the reaction, pH was adjusted to 3-4 with 1N HCl solution and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.42 g, 63%).

To a solution of thiazole-2-carbonitrile (0.42 g, 3.80 mmol) in EtOH (20 mL) was added hydroxylamine hydrochloride (0.53 g, 7.60 mmol) and pyridine (0.27 g, 3.40 mmol). The resulting reaction mixture was refluxed for 15 h. After the completion of the reaction (TLC monitoring), the mixture was concentrated, added EtOH and filtered. The filtrate was evaporated under reduced pressure and used as such for the next step (crude yield 0.50 g, 91% crude yield).

Chloroacetyl Chloride (5.0 mL, 44.5 mmol) was added to N-Hydroxy-thiazole-2-carboxamidine (0.50 g, 3.49 mmol) and K2CO3 (1.0 g, 7.20 mmol). The reaction mixture was heated at 100° C. for 15 min. After the completion of the reaction mixture (TLC monitoring), water (25 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 10% EtOAc-Hexane) to get the desired product (0.18 g, 25%) as a white solid.

To an ice-cold solution of 4-phenoxy-phenylamine (1.0 g, 5.39 mmol) in 10 ml of DCM was added triethylamine (0.90 ml, 5.93 mmol) followed by acetyl chloride (0.50 g, 6.47 mmol). The reaction mixture was stirred at 25° C. for 2 h. After the completion of the reaction mixture (TLC monitoring), water was added extracted with DCM (3×50 mL). The combined organics was dried (Na2SO4), filtered and concentrated to get the desired product (1.20 g, crude yield).

To a solution of N-(4-phenoxy-phenyl)-acetamide (1.20 g, 5.28 mmol) in 10 ml of toluene was added Lawesson's reagent (1.50 g, 3.70 mmol). The reaction mixture was heated at 120° C. for 2 h. After the completion of the reaction (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure. The residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (5:95) as the eluent to provide the title compound (0.78 g, 60.7%).

To an ice-cold solution of N-(4-phenoxy-phenyl)-thioacetamide (0.78 g, 3.20 mmol) in 10 ml of DCM was added Br2 (0.32 ml, 6.40 mmol) dropwise. The reaction mixture was heated at 45° C. for 2 h. After the completion of the reaction (TLC monitoring), the reaction mixture was evaporated under reduced pressure. The residue was basified with NH4OH solution and extracted with ethyl acetate. The combined organics were, dried, (Na2SO4), filtered and concentrated. The residue was purified by column chromatography on silica (230-400 M) using ethyl acetate/hexane (3:97) as the eluent to provide the title compound (0.08 g, 10.3%).

To a solution of 2-methyl-6-phenoxy-benzothiazole (0.06 g, 0.24 mmol) in 5 ml of CCl4 was added NBS (0.039 g, 0.22 mmol) and AIBN (0.004 g, 0.024 mmol). The reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400M) using 1% ethyl acetate/hexane eluent to give the desired product (0.005 g, 6.3%).

To a solution of 7-methylquinoline (0.10 g, 0.70 mmol) in 5 ml of CCl4 was added NBS (0.14 g, 0.77 mmol) and AIBN (0.025 g, 0.15 mmol). The reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After the completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400M) using 1% ethyl acetate/hexane eluent to give the desired product (0.090 g, 58%).

The compounds of Examples 318-333 were synthesised according to the following general procedure: To a solution of reactant (A) in anhydrous DMF was added 2,6-Difluoro-3-hydroxy-benzamide (B) and potassium carbonate (C). The reaction mixture was stirred at 25° C. for 24 h under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica using ethyl acetate/hexane as the eluent to provide the product compound.

TABLE R

Reaction scheme

ane ratio

Reaction scheme

thiazole
acid methyl ester

ane ratio

Reaction scheme

ane ratio

Reaction scheme

ane ratio

Reaction scheme

ane ratio

Reaction scheme

ane ratio

Reaction scheme

ane ratio

Reaction scheme

ane ratio

A mixture of thioacetamide (8.0 g, 106.0 mmol) and 2-bromo-1-(3-methoxy-phenyl)-ethanone (2.0 g, 8.81 mmol) was heated at 140° C. for 6 h under nitrogen atmosphere. After completion of the reaction mixture (TLC monitoring), water (50 mL) was added and extracted with ethyl acetate (3×50 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated. The crude residue was purified over silica gel (230-400 M, 2% EtOAc-Hexane) to get the desired product (1.5 g, 83%).

To a solution 4-(3-methoxy-phenyl)-2-methyl-thiazole (1.50, 7.30 mmol) in the 20 ml of CCl4 was added NBS (2.60 g, 14.60 mmol) and AIBN (0.12 g, 0.73 mmol). The reaction mixture was heated at 100° C. for 2 h under nitrogen atmosphere. After completion of the reaction mixture (TLC monitoring), the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (230-400 M) using 2% ethyl acetate/hexane as a eluent to give the desired product (1.20 g, 45%).

To a solution of 5-Bromo-2-bromomethyl-4-(3-methoxy-phenyl)-thiazole (0.80 g, 2.20 mmol) in 5 ml of anhydrous DMF was added 2,6-Difluoro-3-hydroxy-benzamide (0.38 g, 2.20 mmol) and potassium carbonate (1.06 g, 7.70 mmol). The reaction mixture was stirred at 25° C. for 24 h under nitrogen atmosphere. The reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by column chromatography on silica (60-120 M) using ethyl acetate/hexane (50:50) as the eluent to provide the title compound as white solid (0.50 g, 49%).

To the solution of 3-[5-bromo-4-(3-methoxy-phenyl)-thiazol-2-ylmethoxy]-2,6-difluoro-benzamide (0.50 g, 1.10 mmol) in the 10 ml of acetic acid was added Zn dust (0.50 g, w/w). The reaction mixture was heated at 120° C. for 1 h. After the completion of the reaction mixture (TLC monitoring), water (50 mL) was added and pH was adjusted to 8-9 with NaOH solution and extracted with ethyl acetate (3×100 mL). The combined organics was washed with water, brine, dried (Na2SO4), filtered and concentrated to get the desired product (0.22 g, 53%).

Minimum Inhibitory Concentration (MIC) Testing

Compounds of this invention were tested for antimicrobial activity by susceptibility testing in liquid media. MICs for compounds against each strain were determined by a broth microdilution method according to the National Committee for Clinical Laboratory Standards (NCCLS) guidelines. (NCCLS. 2000. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically-fifth edition. Approved standard M7-A5. NCCLS, Wayne, Pa.)

Briefly, test compounds are prepared in 100 μl of 1.6% DMSO solution in multiwell plates. Several bacterial colonies from a freshly streaked plate are transferred to an appropriate rich broth, such as Mueller Hinton. The cell suspension is adjusted to an optical density of 0.09 and further diluted 1:100 with warm 2× broth. This cell suspension is dispensed into the wells containing compound solution so that the final volume is 200 μl. The plates are incubated overnight (16-20 hours) at 37° C. and turbidity is scored by eye and quantified spectrophotometrically. The MIC is defined as the lowest concentration inhibiting visible growth.

Compounds of the current invention were found to have antimicrobial activity in the MIC assay described above.

Results

Table 1 shows the Minimal Inhibitory Concentration (MIC) of the Examples against Bacillus subtilis 168cA. Activities were scored as ‘A’ if the MIC was ≤8 micrograms/ml, ‘B’ if the MIC was 16 to 64 micrograms/ml and ‘C’ if the MIC was greater than 64 micrograms/ml.

Bacillus subtilis MICs

Example
Activity

100
A

102
A

103
A

104
A

105
A

106
A

107
A

109
A

110
A

111
A

112
A

113
A

114
A

117
A

118
A

119
A

120
A

121
A

122
A

123
A

124
A

125
A

126
A

127
A

128
A

129
C

130
A

132
A

133
A

135
A

136
A

138
C

139
A

140
C

141
A

142
A

143
C

144
C

146
A

148
A

149
A

150
A

151
A

153
A

154
A

155
A

156
A

157
A

158
A

159
A

160
A

161
A

162
A

163
A

164
A

165
A

166
C

168
C

169
C

170
C

172
C

173
C

175
A

176
A

177
A

179
C

180
A

181
A

182
C

185
C

186
A

189
C

192
C

194
C

195
A

196
A

199
C

200
A

201
A

202
A

203
C

205
A

206
A

207
A

208
A

210
A

211
A

212
A

213
A

215
A

216
A

217
A

218
A

219
A

220
A

221
A

222
A

223
A

225
C

227
A

228
A

229
A

230
A

231
A

233
A

234
A

235
A

236
A

240
A

241
A

242
A

243
A

245
A

246
A

247
A

248
A

249
A

250
A

252
A

254
A

255
A

256
A

257
A

258
A

259
A

260
A

263
A

265
A

267
A

268
A

269
A

270
A

271
A

272
A

273
A

274
A

276
A

277
A

278
A

279
A

280
A

281
A

282
A

283
A

284
A

285
A

286
A

287
A

288
A

289
A

290
A

291
A

292
A

293
A

294
A

295
A

296
A

297
A

298
A

299
A

301
A

302
A

303
A

304
A

305
A

306
A

307
A

308
A

309
A

310
A

311
A

313
A

314
A

315
A

316
A

317
A

318
A

319
A

320
A

321
A

322
A

323
A

324
A

325
A

327
A

328
A

329
A

331
A

333
A

Some of the compounds of the Examples were also tested for activity against the pathogenic organism Staphylococcus aureus ATCC29213. Table 2 shows the MICs of the Examples against Staphylococcus aureus. Activities were again scored as ‘A’ if the MIC was 8 micrograms/mi, ‘B’ if the MIC was 16 to 64 micrograms/ml and ‘C’ if the MIC was greater than 64 micrograms/ml.

Staphylococcus aureus MICs

Example
Activity

100
A

102
A

103
A

104
A

105
A

106
A

107
A

111
A

114
A

115
A

117
A

118
A

119
A

120
A

121
A

122
A

123
A

124
A

125
A

126
A

127
A

130
A

132
A

133
A

135
A

136
A

138
C

139
A

140
A

141
A

143
A

144
C

145
C

148
A

153
A

155
A

156
A

157
A

158
A

159
A

161
A

162
A

163
A

164
A

165
A

166
C

168
C

169
C

170
C

172
C

173
C

175
A

177
A

179
C

182
C

185
C

189
C

192
C

194
C

205
A

206
C

208
A

209
C

210
A

215
A

216
A

217
A

218
A

219
A

220
A

221
A

222
A

223
A

224
C

225
C

227
A

229
A

230
A

231
A

232
A

233
A

235
A

236
A

240
A

241
A

242
A

243
A

245
A

246
A

247
A

248
A

249
A

250
A

252
A

257
A

260
A

267
A

269
A

270
A

271
A

272
A

273
A

274
A

276
A

277
A

278
A

279
A

280
A

281
A

282
A

283
A

284
A

285
A

286
A

287
A

288
A

289
A

290
A

291
A

292
A

293
A

294
A

295
A

296
A

297
A

298
A

299
A

302
A

303
A

304
A

305
A

306
A

307
A

309
A

311
A

312
A

313
A

315
A

316
A

317
A

318
A

319
A

320
A

321
A

322
A

323
A

324
A

327
A

333
A

334
A

Some of the Examples were also tested for activity against other bacterial species. Table 3 shows the MICs of the Examples against various bacterial species. Activities were again scored as ‘A’ if the MIC was 8 micrograms/ml, ‘B’ if the MIC was 16 to 64 micrograms/ml and ‘C’ if the MIC was greater than 64 micrograms/ml.

MICs against various bacteria

Activity

Bacillus
Staphylococcus
Staphylococcus
Staphylococcus

ATCC
ATCC
ATCC
ATCC

217
A
A

218
A
A
A
A

236
A

208
A

114
A

106
A
A
A
A

246
A
A
A
A

Some of the Examples were also tested for activity against staphylococcal clinical isolates. Table 4 shows the MICs of the examples against various clinical isolates. Activities were again scored as ‘A’ if the MIC was 8 micrograms/ml, ‘B’ if the MIC was 16 to 64 micrograms/ml and ‘C’ if the MIC was greater than 64 micrograms/ml.

MICs against clinical isolates

Oxacillin
Antibiotic
Other
Example - Activity

ATCC 29213
A
A
A

1134
S

Hospital
A
A
A

753
S

Hospital
A
A
A

1662
S

Hospital
A
A
A

1015
R
Van-S, LZD-S
Hospital
A
A
A

1135
R
Van-S, LZD-S
Hospital
A
A
A

2012
R
Van-I, LZD-S
Hospital
A
A
A

2018
R
Van-I, LZD-S
Hospital
A
A
A

1651
R
Van-S, LZD-R
Hospital
A
A
A

1652
R
Van-S, LZD-R
Hospital
A
A
A

1725
R
Van-S, LZD-R
Hospital
A
A
A

2011
R
Tet-R, MI-S
Hospital (tetK)
A
A
A

757
R
Tet-R, MI-R
Hospital
A
A
A

1729
R
Tet-R, MI-R
Hospital
A
A
A

2147
R
CC-S, SXT-S
Community
A
A
A

2142
R
CC-S, SXT-S
Community
A
A
A

2158
R
CC-R, Doxy-I
Community
A
A
A

2150
R
CC-R, SXT-S
Community
A
A
A

2149
R
CC-R (iMLS),
Community
A
A
A

2175
R
TMP-R
Community
A
A
A

2143
R
Rif-R
Community
A
A
A

A
A
A

1139
S

A
A
A

A
A
A

A
A
A

A
A
A

Some of the Examples were also tested for activity in a mouse Staphylococcus aureus septicaemia model of infection. Table 5 shows the survival at day 7 of infected mice treated with a single intraperitoneal dose of 100 mg/kg of each Example at 1 hour after intraperitoneal inoculation with a lethal dose of Staphylococcus aureus.

Murine Survival

Example
Percent survival

Vehicle control
0