じゅずだま属植物成分の研究 (第3報)

Coixol及び関連化合物の合成

抄録

Coixol was synthesized starting with 5-methoxy-2-aminophenol or its hydrochloride by (1) pyrolysis of its phenylurea derivative, (2) pyrolysis of its phenylurethan derivative, (3) application of phosgene, or by (4) preparation of 6-methoxy-2-thio-benzoxazole (colorless needles, m. p. 173.5-174°), from it to 6-methoxy-2-chloro-benzoxazole (colorless needles, m.p. 63-65°), and hydrolysis of the latter. Isomers of coixol with a methoxyl in the different position and a few of its derivatives were prepared by fusion of the corresponding aminophenol hydrochloride with urea. 4-Methoxybenzoxazolone, colorless needles, m.p. 194-195° (acetate, m.p. 122-124°; benzoate, m. p. 142°; ethoxycarbonyl derivative, m.p. 60°); 5-Methoxybenzoxazolone, colorless needles, m. p. 169-170° (acetate, m.p. 101-102°; benzoate, m.p. 135°; ethoxycarbonyl derivative, m.p. 82-83°); 7-methoxybenzoxazolone, colorless needles, m.p. 148-150° (acetate, m.p. 119-122°; benzoate, m.p. 187-188°; ethoxycarbonyl derivative, m.p. 114-115.5°). These benzoxazolones exhibited an absorption of strong intensity at around 5.65μ due to C=C stretching vibration.