Novel Reactions of Tropylium Salts with Heterocyclic Diamines

The reactions of tropylium salts with 2,5-diamino-1,3,4-thiadiazol, 3,5-diamino-1,2,4-thiadiazol, and 2,6-diaminopyridine have given novel products of substitution of hydrogen atoms of two amino groups in thiadiazols and of hydrogen atoms at С3 and С5 positions in 2,6-diaminopyridine.