Synthesis and antimicrobial evaluation of some new thienopyrimidine derivatives

Reaction of heteroaromatic o-aminonitrile with ethyl N-[bis(methylthio)methylene]amino acetate resulted in annelation of a thieno[3,2-e]imidazo[1,2-c]pyrimidine moiety in a one step process. [1,2,4]Triazolo[4,3-c]thieno- [3,2-e]pyrimidine derivatives were prepared by initial treatment of o-aminonitrile with carbon disulfide, followed by methylation with methyl iodide and subsequent reaction with benzhydrazide and thiosemicarbazide, respectively. Hydrazinothieno[2,3-d]pyrimidine was prepared by cyclization of heteroaromatic o-aminoester with formamide, followed by chlorination and subsequent displacement with hydrazine. Treatment of the hydrazino derivative with acetylacetone, benzaldehyde and acetic anhydride afforded pyrazolylpyrimidine, benzylidenehydrazonopyrimidine and triazolopyrimidine derivatives, respectively. Some of these derivatives exhibited pronounced antimicrobial activity.