Synthesis and IR spectra of some 2-aminobenzoxazole derivatives

A large number of 5-nitro-, 6-nitro-, 5-chloro-, and 6-bromo-2-aminobenzoxazoles were synthesized by the reaction of benzoxazoline-2-thiones with various amines. It was shown by IR spectroscopy that all of the compounds exist in the amino form in solution, whereas the 5-substituted compounds exist in the imino form in the solid state, and the 6-substituted compounds exist simultaneously in the two forms.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 604–607, May, 1981.The authors thank T. Dukhova, P. Braikov, I. Nachev, and T. Georgieva for their assistance in carrying out several of the experiments.