A Facile Synthesis of New 3-(1-Methyl benzimidazol-2-yl) Pyrazolopyrimidine and Pyrimido[2, 1-b][1,3]benzothiazole Derivatives of Potential Biosignificant Interest

A simple route for the synthesis of pyrazolo[1,5-a]pyrimidine derivatives was described through the reaction of readily accessible 4-(1-methyl benzimidazol-2-yl)-3-(methylthio)-1H-pyrazol-5-amine (3) with different reagents is described. Also 2-amino benzothiazole in N, N/-dimethyl formamide and anhydrous potassium carbonate reacted with 2-(1-methyl benzimidazol-2-yl)-3,3-bis(methylthio)acrylonitrile (2) to yield pyrimido[2,1-b]benzo-thiazole (21). The latter was further reacted with selected N-, O- and C- nucleophiles such as aryl amines, hetaryl amines, substituted phenols and compounds with an active methylene group. The in vitro antimicrobial activity of some synthesized compounds was examined. Most of the tested compounds proved to be active as antibacterial and antifungal agents.