New spiro derivative of dihydro-1,2,3-triazolo[1,5-a]pyrimidine as a product of multicomponent reaction

Abstract

[Figure not available: see fulltext.] A new spiro derivative of dihydro-1,2,3-triazolo[1,5-a]pyrimidine – 5'-amino-6'-cyano-4'H-spiro[cyclohexane-1,7'-[1,2,3]triazolo[1,5-a]-pyrimidine]-3'-carboxamide – was prepared by three-component reaction of 5-amino-1,2,3-triazole-4-carboxamide with malononitrile and cyclohexanone; the structure of product was established by X-ray analysis. Microwave activation and conventional heating showed the formation of single product and the same direction of heterocyclization. Available literature data concerning similar reactions using 3-amino-1,2,4-triazole or 2-aminobenzimidazole were reinvestigated experimentally with consideration of alternative structures; structures of products were studied by NMR including NOE experiments.