Transcyclization of benzoxazoles

The reaction of benzoxazoles with aromatic and aliphatic acids, which gives transcyclization products — 2-substituted benzoxazoles — was studied. The reaction of 2-hydroxyacetanilide with aliphatic acids gives a mixture of 2-substituted benzoxazoles. Under similar conditions, 2-methylbenzothiazole, 2-alkyl-²-oxazolines, and 2-alkyl-²-thiazolines do not undergo transcyclization, but ring opening is observed in the latter two cases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1480–1482, November, 1972.