SYNTHESIS AND REACTIONS OF 4-(ARYLHYDRAZINO)COUMARINS

Abstract

The interaction of 4-hydroxycoumarin with phenyl-, 2-chlorophenyl-  and 4-bromophenyhydrazine hydrochlorides in the presence of triethylamine led in all cases to the corresponding 4-(arylhydrazino)coumarins and 1-aryl-3-(2-hydroxyphenyl)-2H-pyrazolin-5-ones. 4-(Arylhydrazino)coumarins reacted with 4-chlorobenzaldehyde in the presence of piperidine acetate to give the corresponding 2-aryl-3-(4-chlorophenyl)[1]benzopyrano[4,3-b]pyrazol-4-ones. The reaction of 4-(4-bromophenylhydrazino)-coumarin with 4-chlorobenzaldehyde in the presence of piperidine acetate and an excess of piperidine gave 2-(4-bromophenyl)-5-(4-chlorophenyl)-3-(2-hydroxyphenyl)-4-(piperidinocarbonyl)pyrazole, but the reaction of phenyl- and 4-(2-chlorophenylhydrazino)coumarins with 4-chlorobenzaldehyde gave 1-aryl-5-(4-chlorophenyl)-3-(2-hydroxyphenyl)-4-(1-piperidino)carbonyl-4,5-dihydropyrazoles.

How to Cite
Strakova, I.; Strakovs, A.; Petrova, M.; Belyakov, S. Chem. Heterocycl. Compd. 2009, 45, 1319.[Khim. Geterotsikl. Soedin. 2009, 1319.]

For this article in the English edition see DOI 10.1007/s10593-010-0428-y