Synthesis and Antimicrobial Activities of Some New Thieno and Furopyrimidine Derivatives

Abstract

Fused pyrimidines, 8,9-dimethyl[1,2,4]triazolo[4,3-c]thieno[3,2-e]pyrimidine 5, 3,8,9-trimethyl[1,2,4]triazolo[4,3-c]thieno[3,2-e]pyrimidine 6, 4-benzylidinehydrazono-5,6  dimethylthieno[2,3-d]pyrimidine 7, 4-[4^/-hydroxybenzylidine]hydrazono-5,6-dimethylthi-eno[2,3-d]pyrimidine 8, 4-[4^/-tolylidin]hydrazono-5,6-dimethylthieno[2,3-d]pyrimidine 9, 4-[4^/-nitrobenzylidine]hydrazono-5-ethyl-6-methylthieno[2,3-d]pyrimidine 10 and 4-[4^/-chlorobenzylidine]hydrazono-5-ethyl-6-methylthieno[2,3-d]pyrimidine 11 are prepared in good yield by an initial treatment of 2-amino-4,5-dimethylthiophene-3-carbonitrile 1 with formic acid, affording 5,6-dimethylthieno[2,3-d]pyrimidin-4(3H)-one 2, which is chlorinated with thionyl chloride and then hydrazinated with hydrazine hydrate. Finally hydrazino compound 4 is reacted with formic acid, acetic anhydrate, benzaldehyde, p-hydroxybenzaldehyde, p-toluayldehyde, p-nitrobenzaldehyde and p-chlorobenzaldehyde to give thienotriazolopyrimidines 5-6 and thienopyrimidines 7-11 respectively. All the compounds have been screened for their antimicrobial activity.

Keywords: Fused pyrimidines; Hydrazino compound; Thienotriazolopyrmidines; Thienopyrimidines; Antimicrobial activity.

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DOI: 10.3329/jsr.v1i2.2299