Abstract The substituted vinylphosphonium salt (E)-MeSCH= C (CN) P+ Ph 3 I− readily cyclizes under the action of benzamidine and 3-amino-s-triazole, but it does not enter cyclocondensation with 2-aminopyridine. The structure of the cyclization product with 3- amino-s-triazole was confirmed by its transformation to 7-imino-6-( triphenylphosphoranylidene)-6, 7-dihydro-s-triazolo [1, 5] pyrimidine which was identified ...
