Reaction of 2-formyl-1,3-cyclohexanediones with cyanoacetamide

Chemistry of Heterocyclic Compounds -     

Synthesis,properties, and X-ray diffraction study of 4-trifluoromethyl-6-phenyl-2-chloro-3-cyanopyridine

4-Trifluoromethyl-6-phenyl-2-chloro-3-cyanopyridine was synthesized, and its molecular-crystal structure was established. The chlorine atom was replaced by amino, mercapto, thiocyanato, and azido groups. The possibility of the direct amination of 4-trifluoromethyl-6-phenyl-3-cyano-2-pyridone by the action of hexamethylphosphoric triamide (HMPT) was demonstrated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1233–1237, September, 1987.     

Synthesis of 2-oxooxazolo[5,4-b]pyridines and their reactions with amines

Riga Technical University, Riga, LV-1658. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 271–272, February, 1995. Original article submitted December 29, 1994.     

Synthesis of heterocyclic compounds on the basis of cyclohexane-1,3-diones (review)

The literature data for the period 1973–1985 on the synthesis, on the basis of cyclohexane-1,3-diones and their derivatives, of heterocyclic compounds that contain a 3-oxocyclohexene structural fragment or are formed as a result of a change in the cyclohexane ring are examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 723–738, June, 1988.     

Reaction of α,α-dimethyl-γ-(1-phe nyl-3-methyl-4-pyrazolyl)- β , γ-butenolide with primary amines and ammonia

The conditions for the formation of amides of 4-keto acids, 2-oxo-5-hydroxypyrrolidlnes, 2-oxo-2,3-dihydropyrroles, or 2-oxo-5-aminotetrahydrofurans by reaction of a Δβ,γ-butenolide with primary amines were determined. The reaction with primary aliphatic amines — benzylamine and methylamine — in ethanol gives 2-oxo-5-hydroxypyrrolidines, while reaction with benzylamine in benzene gives the amide of a 4-keto acid. 2-Oxo-5-anilinotetrahydrofuran is formed in the reaction with aniline.     

Synthesis of heterocyclic compounds from cyclohexane-1,3-diones (review)

The literature data on the synthesis of partially hydrogenated heterocyclic compounds containing a 3-oxocyclohexene structural fragment condensed with five-, six-, or seven-membered oxygen-, nitrogen-, and sulfur-containing heterorings from cyclohexane-1,3-diones and their derivatives are examined in this review.     

4-Bromo-5-(4′-hydroxymethyltriazolyl)pyridazin-3-one and its derivatives

4-Bromo-5-(4-hydroxymethyltriazolyl)pyridazin-3-ones have been obtained for the first time by the reaction of 5-azido-4-bromopyridazin-3-ones with propargyl alcohol. They have been converted into 4-bromo-5-(4-halogenomethyltriazolyl)pyridazin-3-ones.     

α,β-Butenolides

,-Dibromo--('-carbethoxyacetony)-^,-butenolide (I) reacts with amines in diethyl ether solution to give -bromo-amino--('-carbethoxyacetony)-^,-butenolides. Compounds n are converted to -bromo-amino--('-carbethoxyacetony)-^,-butenolides on reaction with amines. The corresponding arylhydrazones (VI and VII) are obtained by the reaction of I and II with p-nitro- and 2,4-dinitrophenylhydrazines. Compound I reacts with phenylhydrazine to give furopyridazine VIII.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 867–871, July, 1972.     

Alkylation of 4-oxo-3-methyl-4,5,6,7-tetrahydroindazoles

The alkylation of 4-oxo-3,6,6-trimethyl-4,5,6,7-tetrahydroindazole with alkyl halides forms mixtures of 1-alkyl and 2-alkyl derivatives which have been separated by fractional crystallization from n-hexane. The 4-oxo-1-alkyl-,-1-aryl-, and -1-acyl-4,5,6,7-tetrahydroindazoles have characteristic frequencies in their IR spectra at 1540-1530 cm^–1, and the corresponding 2-substituted derivatives have frequencies at 1565-1555 cm^–1. The introduction of an alkyl substituent at a nitrogen atom decreases the basicity of 4,5,6,7-tetrahydroindazole by 0.6 orders of magnitude, the 1-alkyl isomers being somewhat stronger bases than the 2-alkyl isomers.     

2-Oxooxazolopyridines. 1. Synthesis of alkyl N-(2-oxo-3-pyridyl)carbamates

A convenient method is proposed for the synthesis of new derivatives of the pyridine series, alkyl N-(2-oxo-3-pyridyl)carbamates (IIa-i, IVa-j), in the reaction of 7-trifluoromethyl-5-phenyl-2-oxooxazolo[5,4-b]pyridines (I, IIIa-j) with alcohols.Riga Technical University, Riga LV-1048. Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 241–249, February, 1997.