2-Trihalogenomethylbenzazoles. Part IV. Reactions with difunctional nucleophiles. Formation of heterocyclic rings on the 2-position of benzazoles

摘要: The reaction of selected 2-trihalogenomethylbenzimidazoles with 1,2-difunctional amines, amino-alcohols, and amino-thiols formed benzimidazoles substituted on the 2-position 2-imidazolin-2-yl, 2-oxazolin-2-yl, 2-thiazolin-2-yl rings. This high-yield method was extended to formation six- seven-membered-ring analogues by trihalogenomethyl group 1,3- 1,4-difunctional nucleophiles. Similarly, aromatic ortho-disubstituted nucleophiles yielded corresponding azole derivatives. Other heterocyclic rings benzimidazole were in reactions semicarbazide mercaptoethanol. nature activation groups these cyclisations is discussed, some cyclisation products are also reported.