反应详情

温度

20 °C

The procedure is as in Example 4, starting with ethyl 6-(3,4-dihydroxyphenyl)-2-dimethylamino-5-methylthio-6-oxo-2,4-hexadienoate (1.9 g) and 1N aqueous hydrochloric acid solution (10.8 cc) in ethanol (10.8 cc). The mixture is heated to boiling for 5 minutes, and then cooled to a temperature in the region of 20° C. After purification by crystallization in isopropyl ether (100 cc), ethyl 6-(3,4-dihydroxyphenyl)-2-hydroxy-5-methylthio-6-oxo-2,4-hexadienoate (0.6 g), m.p. 156° C., is obtained.

1. temperatureThe mixture is heated
2. customAfter purification
3. customby crystallization in isopropyl ether (100 cc)