Synthesis of 2-aminobenzoxazoles and 2-iminobenzoxazolines

The cyclization of sulfonamide derivatives of alkylated 2-hydroxyphenylthioureas in the presence of an ammoniacal solution of silver oxide gives 2-alkylaminobenzoxazole-5-sulfonamides or the corresponding 3-alkyl-2-alkyliminobenzoxazolines. Alkyl-substituted 2-aminobenzoxazole-5-sulfonamides were also obtained by the reaction of benzoxazolylthione with secondary amines and aniline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 173–174, February, 1976.