Synthesis of Novel Heterocycle Systems: 6,8-Dimethyl-2-(Methylsulfanyl)-4-Amino-Substituted Pyrimido[4′,5′:3,4]Pyrazolo[1,5-a]Pyrimidine and 9,11-Dimethyl-5-(Methylsulfanyl)Pyrimido[2′,1′:5,1]Pyrazolo[4,3-e][1,2,4] Triazolo[4,3-c]Pyrimidine

Abstract

Synthesis of novel heterocycle systems: 6,8-dimethyl-2-(methylsulfanyl)-4-amino-substituted pyrimido[4′,5′:3,4]pyrazolo[1,5-a]pyrimidine and 9,11-dimethyl-5-(methylsulfanyl)pyrimido[2′,1′:5,1]pyrazolo[4,3-e][1,2,4] triazolo[4,3-c]pyrimidineThe novel heterocyclic pyrimidopyrazolopyrimidine system was synthesised through cyclisation of 4-hydrazinyl-2,6bis(methylthio)pyrimidine-5-carbonitrile with acetylacetone in high yield. Also, two other tetracyclic systems were synthesised through cyclisation of 4-hydrazinyl-6,8-dimethyl-2-(methylsulfanyl)pyrimido[4′,5′:3,4]pyrazolo[1,5-a]pyrimidine with triethyl orthoformate and sodium nitrite to obtain the pyrimidopyrazolotriazolo pyrimidine and pyrimidopyrazolotetrazolopyrimidine respectively.