Synthesis of various fused pyrimidine rings with their pharmacological and antimicrobial evaluation

Various fused pyrimidine such as furo[2,3-d]pyrimidine, triazolo[1,5-a]pyrimidine, tetrazolo[1,5-a]pyrimidine were synthesized from the reactions of thioxopyrimidine-6(1H)-ones with ethyl chloroacetate (under different reaction conditions), thiourea, and sodium nitrite. Pyrimidine thiones reacted with POCl3/PCl5 to give the chloro derivatives which reacted with sodium azide, and thiourea to give the tetrazolo[1,5-c]pyrimidine, pyrimido pyrimidine. Thioxopyrimidine-6(1H)-ones reacted with benzyl amine to give pyrrolo[2,3-d]pyrimidinethione. Theoretical calculation using MIDO/3, Fukui indices and the heat of formation of some compounds were carried out. The pharmacological and antimicrobial activities of some of the synthesized products were also evaluated