bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aziridinyl ketones XVII. The hydrogenation of 2‐phenyl‐3‐aroylaziridines to aziridinylcarbinols
Authors: Wall Donald K. , Imbach Jean‐Louis , Pohland Albert E. , Badger Robert C. , Cromwell Norman H. 
Published: April 2009

AbstractThe sodium borohydride reduction of both cis and trans‐1‐cyclohexyl‐2‐phenyl‐3‐aroylaziridines provides in each case the corresponding carbinol as a mixture of the two possible diastereoisomeric racemates, whereas reduction of these ketones with lithium aluminum hydride or with lithium diisopropylamide provides only the racemate resulting from attack on the carbonyl group from the least hindered side. Catalytic hydrogenation of a cis aziridinyl ketone cleaved the aziridine ring and provided an amino carbinol.
The synthesis of oximes containing the ferroin group
Authors: Case Francis H. , Mcmenamin Patrick J. 
Published: April 2009

AbstractA series of oximes of substituted 2‐pyridylmethyl and phenyl ketones has been prepared. These all contain the ferroin group (NCCN). The 4‐substituted pyridyl‐syn‐methyl and phenyl ketoximes form chelates with Fe(II).
Ring closure reactions with nitriles. I. Formation of pyrrolo [2,1‐c] [1,2,4] benzothiadiazines and pyrrolo[1,2‐a] quinazolines
Authors: Bell Stanley C. , Conklin George 
Published: April 2009

AbstractPyrrolo[2,1‐c][1,2,4]benzothiadiazines have been prepared from the reactions of o‐amino‐benzenesulfonamides with γ‐cyanopropionaldehydes. Pyrrolo[1,2‐a]quinazolines have been prepared from the reaction of anthranilamides with either γ‐cyanopropionaldehyde or succinic anhydride. The cyclization of a 4‐oxo‐2‐quinazolinepropionic acid has produced a pyrrolo‐[1,2‐a]quinazoline and the isomeric pyrrolo[2,1‐b]quinazoline.
Pyrazoles. II. Reactions of 1‐methyl‐5‐amino‐4‐pyrazolecarboxamide and nitrous acid introduction of a nitro group at position 5 in the payrazole ring
Authors: Cheng C. C. 
Published: April 2009

AbstractAddition of sodium nitrite to a mixture of hydrochloric acid and 1‐methyl‐5‐amino‐4‐pyrazolecarboxamide, at either high or low temperature, yielded 1‐methyl‐4‐hydroxypyrazolo‐[3,4‐d]‐v‐triazine. On the other hand, addition of hydrochloric acid to an aqueous mixture of sodium nitrite and 1‐methyl‐5‐amino‐4‐pyrazolecarboxamide gave, at high temperature (˜ 100°), 1‐methyl‐5‐nitro‐4‐pyrazolecarboxylic acid and at low temperature (˜ 0°), 1‐methyl‐5‐nitrosamino‐4‐pyrazolecarboxylic acid.
Picrylamino‐substituted heterocycles. III. 1,2,4‐triazoles
Authors: Coburn Michael D. , Jackson Thomas E. 
Published: April 2009

AbstractThis paper describes the synthesis of various picryl‐and picrylamino‐substituted 1,2,4‐triazoles and 3,3′‐bi‐1,2,4‐triazolyls. These compounds were prepared by condensing the appropriate 1,2,4‐triazole or amino‐1,2,4‐triazole with a picryl halide. The proton n.m.r. spectra, crystal densities, thermal stabilities, and drop‐weight impact sensitivities of the resulting compounds were determined.
Enazine chemistry II. The mechanism of formation of 1‐(cis‐3‐phenylpropenyl)‐5‐phenylpyrazole from the pyrolysis of cinnamaldehyde azine
Authors: Stern Robert L. , Krause Josef G. 
Published: April 2009

AbstractThe mechanism of pyrazole formation from the thermolysis of α,β‐unsaturated azines has been examined by both kinetic and non‐kinetic methods. The reaction exhibits a large negative entropy of activation, a large primary isotope effect and a positive slope in a Hammett study on cinnamaldehyde derivatives. The reaction was shown to be cleanly intramolecular and was also unaffected by radical traps. A mechanism involving intramolecular 1‐5 abstraction of a proton is presented, which accounts for all of the experimental data.
Thiazolo‐N‐hydroxyuracils
Authors: Bauer Ludwig , Mahajanshetti C. S. 
Published: April 2009

AbstractThe partial Lossen degradation of the hydroxamic acid group at C‐4 or C‐5 of sodium 4,5‐thiazoledicarbohydroxamate (IIIb) and its 2‐methyl analog (IIIe) initiated a multicoursed reaction which furnished a mixture of thiazolo[4,5‐d]‐ and thiazolo[5,4‐d]‐N‐hydroxyuracils. The isomer distribution was sensitive to the solvent systems in which these reactions were carried out. The structure of the isomers so obtained was established by chemical and spectral methods.
Friedel crafts reactions of three‐member ileterocycles II: Alkylation of aromatic compounds with aziridines
Authors: Milstein Norman 
Published: April 2009

AbstractThe Friedel Crafts reaction of propylenimine with symmetrical arenes in the presence of aluminum chloride was investigated. Electron donating substituents increase the α‐methyl‐β‐phenethylamine/ β‐methyl‐β‐phenethylaimine ratio, while increasing the temperature has the opposite effect. In the reaction of chlorobenzene or toluene with aziridine, the nature of the substituent has little effect on the ortho/para ratio.
Synthesis of pyridazine derivatives. XXI. Tetrazolo‐azido transformations in some fused azolopyridazines
Authors: Kovačič A. , Stanovnik B. , Tišler M. 
Published: April 2009

Abstract6‐Azidotetrazolo[1,5‐b]pyridazine (III) has been prepared by two different routes and is easily transformed into the 6‐amino derivative (IV). The attempted cyclization of 6‐hydrazinotetrazolo[1,5‐b] pyridazine (II) into the postulated tricycle has been shown to result in the formation of 6‐azido‐s‐triazolo [4,3‐b]pyridazine (VI), obtained also in a separate experiment from VII. The azido structure of VI has been confirmed from spectroscopic data and from its conversion into 6‐amino‐s‐triazolo [4,3‐b]pyridazine (VIII), obtained in another experiment from VII. Similarly, cyclization of II with cyanogen bromide resulted in the simultaneous formation of the s‐triazolo ring and ring opening of the fused tetrazolo ring, giving IX. For 6‐azido‐2‐phenylimidazo[1,2‐b]pyridazine (XII) the expected azide structure proved to be correct.
4‐Thiazoline‐2‐thiones. V. Kineticvs.thermodynamic control of the conjugate addition at theS‐ vs. N‐positions to acrylonitrile and methyl acrylate
Authors: Humphlett W. J. 
Published: April 2009

AbstractThe basic catalyzed conjugate addition of the title system in methanol was found to occur at either theS‐orN‐atoms, or concurrently at theS‐andN‐atoms, of themagnified imagemoiety of the heterocycle. Evidence indicates that the formation of the two types of adducts depends on an equilibrium between the reactions of conjugate addition and reversal. Certain choice of isolation of the two types of products is allowed by control of the reaction conditions.
The synthesis of some ethyl 3‐(1,2‐dialkylhydrazino)propanoates and their cyclization to 1,2‐dialkyl‐3‐yrazolidinones
Authors: Kornet Milton J. , Ie Tan Sip 
Published: April 2009

AbstractThe preparation of several ethyl 3‐(1,2‐dialkylhydrazino)propanoates (III) by the reaction of 1,2‐dialkylhydrazines with acrylates is described. Compound III is accompanied by small amounts of the bis addition products (V) in the reactions of ethyl acrylate with a few of the hydrazines. Cyclization of III to 1,2‐dialkyl‐3‐pyrazolidinones (IV) was achieved with sodium methoxide. 1,2‐Dialkyl‐5‐methyl‐3‐pyrazolidinones were obtained directly from 1,2‐dialkylhydrazines and ethyl crotonate. A procedure for the preparation of 1,2‐di‐(2‐ethoxycarbonylethyl)hydrazines is also given.
Stereochemistry of epimeric 1‐hydroxy‐N‐methylquinolizidinium iodides
Authors: Temple Davis , Sam Joseph 
Published: April 2009

AbstractThe methiodides of epimeric 1‐hydroxy, 1‐hydroxy‐1‐phenyl, and 1‐hydroxy‐1‐methylquinolizidines were prepared from their respective bases. The previously described but not separated epimeric 1‐hydroxy‐1‐methylquinolizidines were prepared and their configurations elucidated by the use of nuclear magnetic resonance (NMR) and infrared data. Structural assignments of the quinolizidinium iodides were made on the basis of NMR data.
Studies in alkylation. I. Synthesis and reactions of spiro[oxirane‐2,4‐piperidines]
Authors: Fishman Morris , Cruickshank Philip A. 
Published: April 2009

AbstractSpiro[oxirane‐2, 4′‐piperidines] have been prepared by the action of dimethyloxosulfonium methylide on 4‐piperidones. The spiro[oxirane‐2,4′‐piperidines] act as alkylating agents to introduce (4‐hydroxy‐4‐piperidyl) methyl moieties onto heteroaromatic compounds such as 4(3H)‐quinazolone.
The reaction of certain heterocyclic azides with triphenylphosphine
Authors: Vanallan J. A. , Reynolds G. A. 
Published: April 2009

AbstractAzidobenzothiazole and azidobenzimidazole and certain of its derivatives react with triphenyl‐phosphine to give isolatable adducts which decompose thermally to give the corresponding phosphinimines. 2‐Azidobenzoxazole gives an adduct which loses nitrogen at 15–20° and gives the phosphinimine directly. Methylation of the phosphinimines occurs at the hetero nitrogen, whereas benzoylation occurs at the exo nitrogen atom. The structures of the alkylation and aroylation products of the phosphinimines were established.
The synthesis of 2‐chloro‐1‐(β‐D‐ribofuranosyl)benzimidazole and certain related derivatives
Authors: Revankar Ganapathi R. , Townsend Leroy B. 
Published: April 2009

AbstractThe synthesis of 2‐chloro‐1‐(β‐D‐ribofuranosyl)benzimidazole (4b) has been accomplished by a condensation of 2‐chloro‐1‐trimethylsilylbenzimidazole (1) with 2,3,5‐tri‐O‐acetyl‐D‐ribofuranosyl bromide (2) followed by subsequent deacetylation. Nucleophilic displacement of the 2‐chloro group has furnished several interesting 2‐substituted‐1‐(β‐D‐ribofuranosyl)benzimidazoles. 1‐(β‐D‐Ribofuranosyl)benzimidazole (5) and 1‐(β‐D‐ribofuranosyl)benzimidazole‐2‐thione (6) were prepared from 4b and 6 was also prepared by condensation of 2 with silylated benzimidazole‐ 2‐thione (3). Alkylation of 6 furnished certain 2‐alkylthio‐1‐(β‐D‐ribofuranosyl)benzimidazoles and oxidation of 6 with alkaline hydrogen peroxide produced 1‐(β‐D‐ribofuranosyl)benzimidazole‐2‐one (9). The assignment of anomeric configuration for all nucleosides reported is discussed.
1,2,4‐Triazoles. XX. Pyrolytic decomposition of ketone hydrazones derived from pyrid‐2‐ylhydrazine and related bases. Some further examples of the s‐triazolo[4, 3‐α]pyrazine and s‐triazolo[4, 3‐a]quinoxaline series
Authors: Potts K. T. , Schneller S. W. 
Published: April 2009

AbstractPyrolytic decomposition of ketone 2‐heterylhydrazones has been shown to be unsatisfactory for the preparation of fused s‐triazole derivatives. The introduction of more diversified substituents into the s‐triazolo[4, 3‐a]pyrazine and s‐triazolo[4,3‐a]quinoxaline systems has been accomplished and some reactions and spectral characteristics of these ring systems are reported. Isomerization of the s‐triazolo[4, 3‐a]pyrazine system to the s‐triazolo[1,5‐a]pyrazine system is described.
Heterocyclic tautomerisms. II. An investigation of the 2‐arylbenzothiazoline 2‐(benzylideneamino)thiophenol tautomerism. Part 2
Authors: Goetz Frederick J. 
Published: April 2009

AbstractThe reaction between 4‐mercaptoaniline and various aromatic aldehydes was studied as a model system in order to determine which type of substitution on the aryl group in 2‐arylbenzothiazolines (1) might give rise to the greatest possible stabilization of the hypothetical 2‐(benzylideneamino)thiophenol tautomer (II). Regardless of electronic effect of substituents, most aldehydes reacted with 4‐mercaptoaniline to form poly[4‐(benzylideneamino)thiophenols] (III). Aromatic aldehydes substituted in the 2 position with the hydroxyl function reacted to form the stable, monomeric 4‐(benzylideneamino)thiophenols (IV). This stabilization in the monomeric state is presumed to be due to the hydrogen‐bonded nature of these compounds (V). Both monomeric and polymeric compounds reacted with benzalacetophenone in the presence of a basic catalyst in the manner to be expected of the 4‐(benzylideneamino)thiophenol structure (IV) yielding correspondingly substituted 1,3‐diphenyl‐1‐[4‐(benzylideneamino)phenylthio]‐3‐propanones (VI).
The synthesis of pyrimido[4,5‐c]pyridazines and pyrimido[5,4‐c]pyridazines
Authors: Nakagome Takenari , Castle Raymond N. , Murakami Hirotaka 
Published: April 2009

AbstractThe Hofmann reaction on 6‐methylpyridazine‐3,4‐dicarboxamide (1) gave a mixture of 3‐methylpyrimido[4,5‐c]pyridazine‐5,7‐dione (2), 3‐methylpyrimido[5,4‐c]pyridazine‐6,8‐dione (3) and an acid (4) of unknown structure. The Hofmann reaction on pyridazine‐3,4‐dicarboxamide (9) gave a mixture of pyrimido[4,5‐c]pyridazine‐5,7‐dione (10) and an acid (11) of unknown structure. The reaction of 3‐amino‐6‐methylpyridazine‐4‐carboxamide (18) with ethyl orthoformate gave 3‐methylpyrimido[4,5‐c]pyridazin‐5‐one (21). 4‐Aminopyridazine‐3‐carboxamide (36) upon fusion with urea gave pyrimido[5,4‐c]pyridazine‐6,8‐dione (37) while with ethyl orthoformate 36 gave pyrimido[5,4‐c]pyridazin‐8‐one (38). Pyrimido[5,4‐c]‐pyridazine‐8‐thione (39) was obtained by the action of phosphorus pentasulfide on 38. 4‐Amino‐3‐cyanopyridazine (16) when treated with formamide produced 8‐aminopyrimido[5,4‐c]‐pyridazine (41). The synthesis of 4‐aminopyridazine‐3‐carboxamide (36) and 4‐amino‐3‐cyanopyridazine (16), both key intermediates in the synthesis of the novel pyrimido[5,4‐c]pyridazine ring system was accomplished by the Reissert reaction of 4‐aminopyridazine‐2‐oxides and subsequent conversion of the nitrile to the amide.
Tautomeric forms of Oxy‐ and Oxo‐derivatives of 1,3,5‐Triazine. Part VI. Isomerization mechanism and thermal stability of the methyl esters of cyanuric acid
Authors: Paoloni L. , Tosato M. L. , Cignitti M. 
Published: April 2009

AbstractPrevious investigations of the kinetics and the mechanism of the thermal isomerization C3N3(OMe)3 → C3(NMe)3O3 have been continued with a study of the isomerization mechanism of the mixed O,O,N‐ and O,N,N‐trimethyl esters of cyanuric acid. A full discussion of the overall process is given, in which it is assumed that the above mixed esters are intermediates.It is shown that the tautomeric transformation occurs as the consequence of the attack of Me+ cations on the ring nitrogen of the neutral molecules. The presence of such cations in the melt was established by ionic exchange with the H+ of the molten acids. It is also shown that the tautomeric transformation in solution proceeds with the same mechanism.An explanation is proposed for the thermal instability of the mixed esters (which isomerize even in the solid state, more than 20° below their melting point), which is based on the high polarity of these molecules. This property is discussed in terms of electronic structure calculations carried out with the Pariser‐Parr‐Pople approximation of the A.S.M.O., S.C.F., method.
Phthalonimides (1,3,4‐trioxo‐1,2,3,4‐tetrahydroisoquinolines) of potential biological interest
Authors: Buu‐Hoï N. P. , Saint‐Ruf G. , Bourgeade J. C. 
Published: April 2009

AbstractA new simple method for the preparation of phthalonimides (1,3,4‐trioxo‐1,2,3,4‐tetrahydroisoquinolines), consisting of the selenium dioxide‐oxidation of the appropriate homophthalimides, has been devised; the thiosemicarbazones and other derivatives of phthalonimides of possible biological interest (as potential antibacterial, antiviral, or immunosuppressive agents) have been synthesized.
Crystal and molecular structure of 1‐benzyl‐1,2,2‐trimethyl azetidinium bromide
Authors: Moret C. L. , Trefonas L. M. 
Published: April 2009

AbstractThe structure of the compound, 1‐benzyl‐1,2,2‐trimethyl azetidinium bromide has been determined by a single crystal x‐ray diffraction study. The compound crystallizes in the space group Pnam with four formula weights in a unit cell of dimensions a = 14.36, b = 13.73, c = 6.906 Å. The compound is partially disordered with the benzyl part ordered and the remainder of the ring disordered about the mirror plane. The azetidinium ring bears a close resemblance in bond distances, bond angles and conformation to the β‐lactam ring found in penicillin. The disordering is discussed in detail and a comparison of the effects of fusing a second ring to the azetidinium moiety are explored. A final value of R = 0.094 for the 432 independent reflections was obtained.
A study of the synthesis and some reactions of perimidines
Authors: Paragamian V. , Baker M. B. , Puma B. M. , Reale J. 
Published: April 2009

AbstractA study of the preparation of perimidines from 1,8‐diaminonaphthalene and carbonyl compounds is presented. The optimum conditions for the reaction of the above diamine with carboxylic acids and esters, acid chlorides, anhydrides and aldehydes are defined.The chemical behavior and a number of previously unreported reactions of perimidines are presented. The latter includeN‐alkylations, reductions, oxidations and acylations.
Mass spectral and NMR studies of some cinnolines
Authors: Elkins John Rush , Brown Ellis V. 
Published: April 2009

AbstractFragmentation upon electron impact of cinnoline (1) occurs with the consecutive loss of N2 and C2H2. Fragmentation of 4,4′‐dicinnolyl (2) and 4‐styrylcinnoline (4) gives a series of ions leading to the “dibenzoladderene” ion (3) and the 1‐phenylbenzodibutylene ion (5) respectively. Fragmentation of 4‐styrylquinoline (6) also leads to 5, but of more interest is the loss of H. during ring rearrangement to give the highly resonance stabilized 3‐styrylbenzocyclo‐pentadieneoneimine ion (7) which then loses N. Fragmentation of various other substituted cinnolines follow different pathways: 4‐methylcinnoline (8) apparently fragments through the “1,2‐diazatropylium” ion (9); nitrocinnolines fragment with initial loss of the nitro substituent; aminocinnolines fragment with initial loss of N2; and 4‐cinnolone (17) fragments with the consecutive loss of two HCN's and CO.The NMR spectra of cinnolines generally show the following order of deshielding: 3‐proton > 8‐proton > 4‐proton. The spectra of cinnolinum chloride (18) is interpreted in terms of protonation at N‐1 of 1, and the spectrum of 17 is interpreted in terms of strong intermolecular hydrogen bonding.
Electron‐impact induced fragmentation of 2‐substituted pyridines and picolines
Authors: Keller G. H. , Bauer L. , Bell C. L. 
Published: April 2009

AbstractThe fragmentation patterns obtained upon electron impact on 2‐nitro‐, 2‐chloro, and 2‐aminopyridines, as well as those of the corresponding 3‐, 4‐, 5‐ and 6‐picolines were examined. There was considerable departure from those patterns reported for the corresponding benzenoid derivatives. Although the molecular ion from 2‐nitro‐3‐picoline did not show fragment ions attributable to an “ortho‐effect” (unlike o‐nitrotoluene), those from 2‐chloro‐ and 2‐amino‐3‐picolines did show a loss of HCl and NH3, respectively. Quite unexpectedly the ions from 2‐chloro‐ and 2‐amino‐6‐picolines also lost HCl and NH3. Such meta‐eliminations for the 2‐substituted‐6‐picolines are postulated to be preceeded by either hydrogen or methyl migration. The mass spectra of 2‐pyridone, 2‐pyridthione and their respective 3‐, 4‐, 5‐ and 6‐methyl analogs were also studied. The primary fragmentations of the 2‐pyridones were as expected from those reported in the literature. The ions from 3‐ and 6‐methyl‐2‐pyridones lost water also, the former being another example of an “ortho‐effect” observed in this series. Of the thiones, the fragmentations of 3‐methyl‐2‐pyridthione proved most unique since its molecular ion showed besides the loss of HS, the pronounced elimination of H2S, the latter presumably due to an “ortho‐effect.” Figures are presented to illustrate the patterns and metastable ions are indicated when found for the transitions discussed.
Solvent‐free fluorination of partially‐chlorinated heterocyclics: Synthesis of 2,6‐difluoropyridine from 2,6‐dichloropyridine
Authors: Boudakian Max M. 
Published: April 2009

AbstractPrevious studies on the solvent‐free fluorination of partially‐chlorinated heterocyclics such as 2‐chloropyridine, 2,3,4,6‐ and 2,3,5,6‐tetrachloropyridine, and 2,4,6‐trichloropyrimidine with alkali metal fluorides or hifluorides revealed an inconsistent product pattern: degradation, partial or complete halogen exchange could occur. The present study concerned application of the solvent‐free halogen exchange technique (potassium fluoride) to 2,6‐dichloropyridine (I). The latter, as well as its fluorination products, exhibited good stability at 400° to provide an 80% yield of 2,6‐difluoropyridine (III). Moderation of fluorination conditions also permitted isolation of the precursor, 2‐chloro‐6‐fluoropyridine (II), a new compound. The above solvent‐free process to III is superior to the previously‐reported halogen‐exchange route in dimethyl sulfone solvent on the basis of yield, reaction time and number of processing steps.
The synthesis of oxygen analogs of cepham. A new bicyclic system
Authors: Sheehan John C. , Dadiac Miroslav 
Published: April 2009

AbstractThe synthesis of a new bicyclic system has been reported. Three substituted 5,6‐dihydro‐1,3‐oxazines have been condensed to a fused β‐lactam ring system by use of phthaloylglycyl chloride. The resulting phthalimido compounds were dephthaloylated to the corresponding oxygen analogs of cepham (2).
A convenient synthesis of certain 1‐(β‐D‐ribofuranosyl)benzotriazoles
Authors: Revankar Ganapathi R. , Townsend Leroy B. 
Published: April 2009

AbstractThe synthesis of 5,6‐dichloro‐1‐(β‐D‐ribofuranosyl)benzotriazole (4a), 5,6‐dimethyl‐1‐(β‐D‐ribofuranosyl)benzotriazole (4b) and 1‐(β‐D‐ribofuranosyl)benzotriazole (4c) in good yield has been accomplished by the condensation of the appropriate 1‐trimethylsilylbenzotriazole (1a, 1b, and 1c) with 2,3,5‐tri‐O‐acetyl‐D‐ribofuranosyl bromide (2) followed by subsequent deacetylation of the reaction products. The assignment of anomeric configuration and site of glycosidation for all nucleosides reported is discussed.
The synthesis of polymethylquinolines and 1,10‐phenanthrolines
Authors: Case Francis H. , Wisneski Harris H. 
Published: April 2009

AbstractSeveral polymethyl‐1,10‐phenanthrolines were synthesized by the use of 3‐methyl‐3‐penten‐2‐one in Skraup reactions. The behavior of this ketone as well as that of 4‐hydroxy‐2‐pentanone and 4‐hydroxy‐3‐methyl‐2‐bulanone with various substituted anilines was studied.
The conversion of azobenzenes to phenazines: A new molecular rearrangement
Authors: Abramovitch R. A. , Davis B. A. 
Published: April 2009

AbstractWhen azobenzenes arc heated with ferrous oxalate or with a fused mixture of aluminum chloride and sodium chloride the corresponding phenazines are formed in low yield. Azobenzene itself is exceptional in giving benz[c]cinnoline with AlCl3‐NaCl. Azoxybenzenes and ferrous oxalate give azobenzenes and some phenazines, while azoxybenzene itself also gives 2‐hydroxyazobenzene via a Wallach‐type rearrangement. The rearrangements are thought to occur at the surfaces of the reagent. No rearrangement to the phenazines occurs in the absence of the reagent.
Studies on the syntheses of heterocyclic compounds. Part CCLXXIII. Synthesis of C‐nordihydrocorynantheol and its related compounds
Authors: Kametani T. , Ihara M. , Suzuki T. , Shima K. 
Published: April 2009

AbstractMannich reaction of tryptamine with 3,3,4‐triethoxycarbonylhexaldehyde (IV) gave the cyclized product (VIII), whose hydrolysis, followed by decarboxylation, afforded the acid (IX). After esterification of IX, reduction of ester (X) with lithium aluminum hydride gave the C‐nordihydrocorynantheol (II). The syntheses of IV and XV were also described. Furthermore, the Mannich reaction of L‐N‐benzyl‐1‐methyltryptophan methyl ester (XV) with IV was also examined. This reaction gave the ester (XVII), which was hydrolyzed and decarboxylated to give the acid (XVIII). Esterification of XVIII, followed by catalytic hydrogenation, gave the lactam (III).
An improved synthesis of various racemic polyphenolic tetrahydroisoquinoline alkaloids
Authors: Teitel S. , Brossi A. 
Published: April 2009

AbstractAn improved and straightforward synthesis of (±)‐coclaurine (Va), (±)‐isococlaurine (Vb), (±)‐reticuline (VIIIa) as well as an alternate route to an intermediate in the synthesis of (±)‐multifloramine, the (±)‐diphenol (VIIIb), is described.