Synthesis of 1,3,5-triazineselones from imidoyl isoselenocyanates and amidines

Abstract

Whereas the reaction of N-phenylbenzimidoyl isoselenocyanate (1a) with N-phenylbenzamidine (5a) at room temperature gave the corresponding 1,3,5-triazine-2(1H)-selone (6a), the analogous reaction with the unsubstituted benzamidine (5b) led to di-1,3,5-triazin-2-yl diselenide (7b) via oxidative dimerization of the intermediate 1,3,5-triazine-2-selenol. In a similar manner, 1 and 2-amino-3,4,5,6-tetrahydropyridine (8) yielded the cyclohexa-1,3,5-triazine- 4-selone (9), which, in the presence of a strong base, reacted with a second molecule of isoselenocyanate to give the tricyclic 1,3,5-triazineselone (10). Finally, 2-amino-4,5-dihydro-1,3-thiazole (11) underwent the reaction with various isoselenocyanates (1) to yield 1,3-thiazolo[3,2-a][1,3,5]triazine-4-selones (12).