V. P. Khilya

CHEMISTRY OF 3-HETARYLCOUMARINS. 1. 3-(2-BENZAZOLYL)COUMARINS

The reaction of substituted salicylaldehydes with 2-benzimidazolyl- and 2-benzothiazolylacetonitriles gives the corresponding 3-hetarylcoumarins. The alkylation, acylation, and aminomethylation reactions of these 7-hydroxy-substituted hetero isoflavonoid analogs has been studied.

Chemistry of modified flavonoids

Abstract2,4-Dihydroxyphenoxyacetophenones were obtained by the reaction of resorcinol with phenoxyacetonitrile under the conditions of the Houben-Hoesch reaction. Their cyclization under the conditions of acid and alkaline catalysis gave new derivatives of 3-phenoxychromone.

Chemistry of 3-hetarylcoumarins 3*. Synthesis and aminomethylation of 7′-hydroxy-3,4′- bicoumarins

An improved procedure for the synthesis of 7′-hydroxy-3,4′-bicoumarins has been developed. Their 8′-aminomethyl derivatives were obtained by interaction with aminals.

CONDENSATION OF 2-(4-CHLOROPHENYL)-1-(2,4-DIHYDROXYPHENYL)ETHANONE WITH N , N -DIMETHYLFORMAMIDE DIMETHYL ACETAL: AN EFFECTIVE APPROACH TO 3-(4-CHLOROPHENYL)-7-METHOXY-4 H -CHROMEN-4-ONE, N,O- AND N,N-HETEROCYCLES

A convenient sequence for the preparation of 2-(4-chlorophenyl)-1-(2,4-dimetoxyphenyl)-3-(dimethylamino)prop-2-en-1-one has been developed. It has been demonstrated that the use of 1-(2,4-dihydroxyphenyl)ethanone or 1-(2-hydroxy-4-methoxyphenyl)ethanone in a condensation reaction with N,N-dimethylformamide dimethyl acetal leads to their heterocyclization to give an isoflavone. Reactions of the enamino ketone with N,O- and N,N-binucleophiles have been studied; as the result, 4,5-diarylisoxazole, 4,5-diarylpyrazoles, and 4,5-diaryl-substituted 2-aminopyrimidine have been obtained in good yields.

Synthesis of 6-alkyl-4-[5-dialkylaminomethyl-4-(4-methyl-1,3-thiazol-2-yl)-1H-pyrazol-3-yl]-1,3-benzenediols

6-Alkyl-2-dialkylaminomethyl-7-hydroxy-3-(4-methyl-1,3-thiazol-2-yl)-4H-chromen-4-ones recyclized into 6-alkyl-4-[5-dialkylaminomethyl-4-(4-methyl-1,3-thiazol-2-yl)-1H-pyrazol-3-yl]-1,3-benzenediols under the influence of hydrazine hydrate.

2-R-7-Hydroxy-8-methyl-3-(2-quinolyl)chromones

By condensation of 2-methyl resorcinol with 2-quinolyl acetonitrile, we have synthesized α-(2-quinolyl)-2,4-dihydroxy-3-methylacetophenone, which when reacted with carboxylic acid anhydrides followed by hydrolysis yields 2-R-7-hydroxy-8-methyl-3-(2-quinolyl)chromones.

Chemistry of the hetero analogs of isoflavones. 22. Mannich reaction in the benzimidazole and benzothiazole analogs of isoflavones

New 3-(2-benzothiazolyl)chromones were obtained by the reaction of 2-(2,4-dihydroxy-5-ethylphenacyl)-benzothiazole with triethyl orthoformate or carboxylic acid anhydrides. Aminomethylation of the chromones and also of familiar 3-(2-benzimidazolyl)chromones by substituted 1,1-diaminomethanes gave Mannich bases.

Features of the α-azolyl-2-hydroxy-acetophenones reaction with chloroacetyl chloride

The patent [1] reports the synthesis of 2-chloromethyl-7-hydroxyisoflavones by condensation of -aryl2-hydroxyacetophenones with chloroacetic acid anhydride and subsequent acid hydrolysis of the 7-acyloxy group. In our study of the reactivity of -hetaryl-2-hydroxyacetophenones of type 1 we have shown that chloroacetyl chloride acylation of the derivative with a 5-phenyl-1,3,4-thiadiazol-2-yl substituent gives a 2-chloromethylchromone of type 2 [2], while both the -(2-pyridyl)and -(2-quinolyl) derivatives form the products of subsequent intramolecular cyclization with annelation of indolizine or pyrroloquinoline ring to the chromone ring [3, 4].

Reduction of 3-(carboxyaryl)isocoumarins with sodium borohydride

Reduction of 3-(carboxyaryl)isocoumarins with sodium borohydride proceeds with formation of corresponding 3-carboxyaryl-3,4-dihydroisocoumarins or isomeric dihydrophthalides, 3-(2-carb-oxybenzyl)-2-benzofuran-1(3H)-ones. Derivatives at the carboxyl group of 3-carboxyaryl-3,4-dihydro-isocoumarins and 3-(2-carboxybenzyl)-2-benzofuran-1(3H)-ones have been obtained.

Synthesis of 6-alkyl-2-dialkylaminomethyl-7-hydroxy-3-(4-methylthiazol-2-yl)-4H-chromen-4-ones

Amination of 6-alkyl-2-chloromethyl-7-hydroxy-3-(4-methylthiazol-2-yl)-4H-chromen-4-ones by secon-dary cyclic amines gives the corresponding 2-dialkylaminomethyl derivatives.