Abstract
Compactsized, multifunctional 2- (N-cyanoimino) thiazolidine (NCT) (1) derivatives exhibited wide range reactivities depending on the N (3) -substituent and the reagents used. 3-Acyl-NCTs (4) were proved to be excellent acylating reagents for amines, alcohols, and thiols. NCT derivatives were converted to various heterocyclic compounds, e.g.., imidazo [2, 1-b] thiazoles (7), 2-aminothiazolo [3, 2-b] -1, 2, 4-triazole (8), triazoles (12, 13), 2, 4-diamino-s-triazines (17, 18, 21), and 1, 2, 4-thiadiazin-3-ones (25). In addition, the regioselectivity of hydride reduction of 5 could be controlled by changing the reagents. Other interesting alkyl or acyl migrations were also observed in the reaction of 5 and 6, and a new synthetic pathway to an anti-ulcer agent, cimetidine (43), was developed utilizing an alkyl migration reaction.
