Method for treating tuberculosis with 2-(2-substituted-phenyl)-2-oxazolines and related 5-membered heterocycles represented by the formula ##STR1## Y.sub.1 is e.g. an ester or amide forming group, and X is O, S, or NH; and pharmaceutically acceptable formulations useful therein are provided. A preferred method comprises administering (S)-benzyl2-[2-(benzyloxy)phenyl]-2-oxazoline-4-carboxylate in a suitable formulation. The compounds of the above formula are prepared by known methods, e.g. the oxazolines are obtained by coupling a substituted benzoic acid with a serine ester or threonine ester and cyclizing the coupled product.