Synthesis of 1,2,3-thiadiazolo[5,4-d]pyrimidines

We have obtained a series of 1,2,3-thiadiazolo[5,4-d]pyrimidines by condensation of 5-(R-amino)-substituted-1, 2, 3-thiadiazoie-4-N-R-(thio)carboxamides with ortho esters.Department of the Technology of Organic Synthesis, Urals State Technical University, S. M. Kirov Urals Polytechnical Institute, Ekaterinburg. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1124–1127, August, 1996. Original article submitted May 24, 1996.