1,2,4-Triazolo[4,3-c]pyrimidines from 4-acylhydrazinopyrimidines.

COCCO MT;CONGIU, CENZO;MACCIONI A;ONNIS, VALENTINA

1992-01-01

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Abstract

The reaction of N1-acetylacetamidrazones 1 with N-[bis(methylthio)methylene]cyanamide (2) at room temperature in the presence of potassium carbonate in dimethyl sulfoxide affords good yields of ethyl 4-acylhydrazino-2-amino-6-methylthio-5-pyrimidine carboxylate 3. By briefly refluxing compounds 3 in dimethyl sulfoxide, 1,2,4-triazolo[4,3-c]pyrimidine derivatives 4 were obtained. When equimolecular amounts of N1-acylacetamidrazones and compounds 2 were refluxed in dimethyl sulfoxide/toluene, compounds 4 were obtained directly.