Molecular crystal structure and chemical properties of 4-phenyl-3,5-diethoxycarbonyl-1,2,6-trimethyl-1,2-dihydropyridine

The molecular crystal structure of 4-phenyl-3,5-diethoxycarbonyl-1,2,6-trimethyl-1,2-dihydropyridine has been investigated by x-ray structural analysis. The three-dimensional structural properties of the molecule have been compared against the large observed reactivity of the 3-ethoxycarbonyl group with respect to nucleophilic substitution reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1236–1239, September, 1991.     

Structure and properties of 2,4a-dimethyl-4-phenyl-3-ethoxycarbonyl-5-oxo-4a,5-dihydro-4H-indeno[1,2-b]pyridine

The molecular and crystal structure of 2,3a-dimethyl-4-phenyl-3-ethoxycarbony-5-oxo-4a,5-dihydro-4H-indeno[1,2-b]pyridine has been determined, and its reduction and alkaline and acid hydrolysis reactions have been studied.Translated from Khimiya Geterotsiklicheskikh Soedineii, No. 10, pp. 1388–1392, October, 1984.     

Synthesis and properties of derivatives of 1,4-dihydropyrimidine-5-carboxylic acid

1,4-Dihydropyrimidines were synthesized by reductive dethionation of the corresponding 2-thiono-4-aryl-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid derivatives, and some of their properties were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1223–1227, September, 1986.     

Synthesis of N-unsubstituted and N-methyl derivatives of 4-aryl-2,6-dimethyl-1,2-dihydropyridine-3,5-dicarbonitriles

In the reduction of 2,6-dimethyl-4-arylpyridine-3,5-dicarbonitriles or their N-oxides by sodium borohydride, a mixture of 1,2- and 1,4-dihydropyridine-3,5-dicarbonitriles is formed. 1,2,6-Trimethyl-4-aryl-1,2-dihydropyridine-3,5-dicarbonitriles were obtained by reducing the corresponding pyridinium perchlorates or by alkylating 4-aryl-2,6-dimethyl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives by methyl iodide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 81–85, January, 1987.     

Synthesis of ethoxycarbonyl-1,4- and -1,2-dihydropyridinecarboxylic acid amides

3-Carbamoyl derivatives of 4-phenyl-5-ethoxycarbonyl-2,6-dimethyl-1,4-dihydropyridine were obtained by cyclocondensation of 2-benzylideneacetoacetic ester with -aminocrotonic acid amide or anilides. In the alkylation of 4-phenyl-5-ethoxycarbonyl-2,6-dimethyl-1,4-dihydropyridine-3-carboxylic acid anilides the amido group is initially alkylated, after which the ring NH group is alkylated, while the thiocarbamoyl group is converted to a cyano group. Reduction of the pyridinium salts gave 3- and 5-carbamoyl derivatives of 4-phenyl-1,2,6-trimethyl-1,2-dihydropyridine-5- and -3-carboxylic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1665–1673, December, 1991.     

New derivatives of 4-aryl-2,6-dimethyl-3,5-diacetyl-1,4- and 1,2-dihydropyridines

4-Aryl-1,2,6-trimethyl-3,5-diacetyl-1,4-dihydropyridines and the corresponding pyridinium salts, which upon reduction with NaBH₄ form 4-aryl-1,2,6-trimethyl-3,5-diacetyl-1,2-dihydropyridines, were synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 508–513, April, 1983.     

Recyclization of 3,5-diacetyl- and 3,5-dicyanopyridinium salts under the influence of bases

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 848–849, June, 1990.     

Preparation of 3-substituted isocoumarins in the reactions of homophthalic anhydride and its derivatives

Acetylation of 4-nitrohomophthalic anhydride gave 4-acetyl-7-nitroisochroman-1,3-dione, which was converted to 3-methyl-7-nitroisocoumarin. 3-Benzylisocoumarin derivatives were synthesized by reaction of homophthalic anhydrides with arylacetic acids in acetic anhydride and triethylamine.Communication XXVIII from the series Condensation of Dicarboxylic Acid Anhydrides with Compounds Containing Active Methylene Groups. See [1] for communication XXVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1487–1489, November, 1977.     

Synthesis of 5-oxoindeno[1,2-b]pyridinium salts

When N-methylated 4-aryl-5-oxo-4,5-dihydroindeno[1,2-b]pyridines are oxidized with hydrogen peroxide in the presence of perchloric acid, in addition to the formation of the indenopyridinium perchlorates, cleavage of the dihydropyridine ring occurs, giving the 2-arylideneindan-1,3-dione.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 88–90. January, 1986.