Studies on the Constituents of Coix Species. II

On the Chemical Structure of Coixol

Abstract

Coixol, C₈H₇O₃N, was isolated as colorless needles, m.p. 151-152°, from the portion soluble in alkali hydroxides, of the root of Coix Lachryma-Jobi L. var. frumentaced Makino. Decomposition of coixol with conc. hydrochloric acid, in the presence of stannous chloride, yielded 5-methoxy-2-aminophenol hydrochloride, m.p. 214°. Therefore, coixol was assumed to be 6-methoxybenzoxazolone and was confirmed by synthesis. Following coixol derivatives were prepared: N-Acetylcoixol, colorless needles, m.p. 147.5°. N-Benzoylcoixol, colorless needles, m.p. 162-162.5°. N-Ethoxycarbonylcoixol, colorless plates, m.p. 107°.