Research in the field of furopyridines. 2. Synthesis and steric structure of 6-methyl-1-hetarylidene-3,4-dioxo[3,4-c]pyridines

By condensation of 6-methyl-3,4-dioxo-1H-furo[3,4-c]pyridine with heteroaromatic aldehydes, furfurylidene- and thenylidenefuropyridinediones have been obtained. By means of ¹H NMR spectrometry using the nuclear Overhauser effect, it has been established that these compounds have the cis-s-cis and cis-s-trans conformations, respectively.For Communication 1, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 29, No. 5, pp. 633–638, May, 1993.     

Synthesis and reactivity of thieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridine-2,3-diamines

It has been established that the interaction of N¹-(2-hydroxyphenylmethylthieno[2,3-b]pyrid-3-yl)arylamides with hydrazine hydrate leads to thieno[2,3-b]pyridine-2,3-diamines. It was shown that the reaction of the latter with acetylacetone and acetoacetic ester occurs regioselectively at the amino group in position 3 of the thiophene ring. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1400–1408, September, 2007.     

Synthesis of substituted benzoxazinylthieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridines by the reaction of (3-cyanopyridin-2-ylthio)acetic acids or their amides with <Emphasis Type="Italic">o</Emphasis>-aminophenyl(diphenyl)carbinol

A general method for the synthesis of 3-amino-2-(4,4-diphenyl-4H-3,1-benzoxazin-2-yl)thieno[2,3-b]pyridines was proposed. The method involves reactions of (3-cyanopyridin-2-ylthio)acetic acids or their amides with o-aminophenyl(diphenyl)carbinol in nitromethane in the presence of perchloric acid followed by neutralization of the resulting salts.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2759–2762, December, 2004.     

Asymmetric catalytic synthesis of lysine by hydrogenation of α-nitrocaprolactam

Conclusions The enantioselective hydrogenation of-nitrocaprolactam (I) is effected on a chiral Pd complex, obtainedin situ in the presence of S--phenylethylamine, to give S--aminocaprolactam (II), hydrolysis of which gives S-lysine. The optical yield varies from 1 to 13% according to the solvent and concentration of chiral ligand. On a Pd complex with S-N-isopropyl--phenylethylamine, enantioselective hydrogenation of (I) gives an excess of the S-enantiomer of (II) (2%). On a Pd complex with S-phenylalaninol, hydrogenation of (I) leads to the R configuration of (II) with EE 7.2%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1597–1600, July, 1987.     

Asymmetrical synthesis of lysine derivatives

Conclusions The stereoselective aminolysis of the azlactone of DL-diacetyllysine by the action of S--phenylethylamine in t-BuOH leads to an excess of the SS-diastereomer of the -phenylethylamine or diaceyllysine. Crystallization of the mixture of diastereomeric amides gave the optically pure S--phenylethylamide of S-diacetyllysine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 925–927, April, 1986.     

Synthesis and Properties of Substituted Isoxazolo[3',4':4,5]thieno[2,3-b]pyridines

We synthesized derivatives of a novel heterocyclic system, isoxazolo[3',4':4,5]thieno[2,3-b]pyridine by sequential conversions in three steps: isomerization of 2-(2-R-ethylthio-2-oxo)-3-pyridyl cyanides obtained by alkylation from substituted 3-cyano-2(1H)-pyridinethiones by -halomethyl ketones in alkaline medium, to form 3-aminothieno[2,3-b]pyridines; diazotization of the amino group followed by nucleophilic substitution of the diazonium group by an azido group, bypassing the step of isolating the diazonium salts; and thermolysis of the azides formed.     

Electrochemical synthesis and studies of substituted 2-thiopyridines

A series of substituted 2-alkyl(aryl-, hetaryl-)thiopyridines was prepared by cathodic electrolysis of thiols in the presence of 2-chloro-3-cyano-4-methoxymethyl-6-methylpyridine or 4-chloro-6-methyl-3-oxo-1H-furo[3,4-c]pyridine. The reaction of 3-cyano-4-methoxymethyl-6-methyl-2(1H)-thiopyridone with alkyl halides in the presence of KOH is regioselective and leads toS-alkyl derivatives. The advantages of electrosynthesis for the preparation of 2-alkylthiopyridines fused with 2(5H)-furanone and of 3-aminothieno [2,3-b]pyridines is demonstrated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2215–2219, December, 1994.     

Catalytic asymmetric synthesis of lysine α-phenylethylamide by diastereoselective hydrogenation

Conclusions The catalyzed asymmetric synthesis of R-lysine S--phenylethylamide has been carried out by the diastereoselective hydrogenation of 5-cyano-2-hydroxyiminovaleric acid S--phenylethylamide over a skeletal nickel catalyst in a solvent containing -phenylethylamine, at raised pressures. The excess of the RS-diastereoisomer was 6–12%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 849–852, April, 1987.