反应详情

The procedure is as in Example 4 for the preparation of ethyl 6-phenyl-6-oxo-5-methylthio-2-dimethylamino-2,4-hexadienoate, starting with N-(3-dimethylamino-3-ethoxycarbonylpropenylidene)-N-methylmethanaminium tetrafluoroborate (11.4 g), a 2M ethanolic solution of sodium ethylate (60 cc) and 4-[2-(methylthio)acetyl]pyrocatechol (7.9 g) in ethanol (60 cc). After purification on a silica column with a mixture of cyclohexane and ethyl acetate (50:50 by volume) as eluent, ethyl 6-(3,4-dihydroxyphenyl)-2-dimethylamino-5-methylthio-6-oxo-2,4-hexadienoate (2.4 g), m.p. 144° C., is obtained.

1. customAfter purification on a silica column
2. additionwith a mixture of cyclohexane and ethyl acetate (50:50 by volume) as eluent