反应详情

温度

65 °C

To a solution of (Z)-2-(2-t-butoxycarbonylaminothiazol-4-yl)-2-pentenoic acid methyl ester (425 mg: 1.4 mMol.) in isopropanol (1.3 ml) and water (3.7 ml) is added sodium hydroxide (163 mg: 4.1 mMol.), and the mixture is stirred at 65° C. for 90 minutes. The reaction mixture is adjusted to pH 4.7 with 35% hydrochloric acid and kept at 20° C. for 1 hour. The separating crystals are collected by filtration, washed with isopropanol, and dried to give (Z)-2-(2-t-butoxycarbonylaminothiazol-4-yl)-2-pentenoic acid (325 mg). Yield: 86%. mp. 187° C. (decomposition). NMR δ(CDCl3) ppm: 1.09(t, J=7.6 Hz, 3H), 1.55(s, 9H) 2.64(qd, J=7.6 Hz, 2H), 6.69(t, J=7.6 Hz, 1H), 6.96(s, 1H). IR ν(CHCl3) cm-1 : 3160, 2548br, 1721, 1685, 1556, 1252, 1156.

1. waitkept at 20° C. for 1 hour
2. filtrationThe separating crystals are collected by filtration
3. washwashed with isopropanol
4. customdried