SYNTHESIS OF 1,3,4-THIADIAZOLO[3,2-A]PYRIMIDINES AND IMIDAZO[2,1-B]-1,3,4-THIADIAZOLES AS LEISHMANICIDES

Various 2-alkylthio-5-imino-7H-1, 3, 4-thiadiazolo[3, 2-a]pyrimidin-7- ones (3a-f) have been prepared by the base-catalysed condensation-cycl ization of 2a-f and ethyl cyanoacetate. Several tricyclic compounds (5 a-e) have also been synthesized from the interaction of 2a-d with cycl ic beta-ketoesters (4a,b). Reaction of 2c-f with omega-bromoacetopheno ne has led to the formation of 6a-d. Some of the synthesized compounds have been screened for their in vivo leishmanicidal activity against L. donovani.