Synthesis, isomerization, and antimicrobial evaluation of some pyrazolopyranotriazolopyrimidine derivatives

Abstract

6-Amino-5-imino-pyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidine derivative 4 and pyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidin-5- ylhydrazine derivative 5 were prepared starting from 6-amino-3-methyl-4-(p- nitrophenyl)-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile 1. The synthesis and structure characterization of 9,11-dihydropyrazolo[4′,3′:5,6] pyrano[3,2-e][1,2,4]triazolo[4,3-c]pyrimidine derivatives 7 and 9 and their isomerization to 9,11-dihydropyrazolo[4′,3′:5,6]pyrano[3,2-e] [1,2,4]triazolo[1,5-c]pyrimidine derivatives 6 and 8, respectively, under different suitable reaction conditions are reported. Moreover, the synthesis of 9,11-dihydropyrazolo[4′,3′:5,6]pyrano[3,2-e] tetrazolo[1,5-c] pyrimidine derivative 14 and N9-acyclic nucleoside 15 are described. Some of the prepared products showed potent antimicrobial activity. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.