Cc. Lockhart et Jw. Sowell, SYNTHESIS OF SUBSTITUTED FURO[3,2-E][1,2,4]TRIAZOLO[4,3-C]PYRIMIDINESAND FURO[3,2-E]TETRAZOLO[1,5-C]PYRIMIDINES, Journal of heterocyclic chemistry, 33(3), 1996, pp. 659-661
A series of substituted furo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines a
nd furo[3,2-e]tetrazolo[1,5-c]pyrimidines were obtained from reactions
of substituted 2-dimethylamino-4-hydrazinofuro[2,3-d]pyrimidines with
orthoesters or sodium nitrite in acetic acid, respectively.