反应详情

2,2-dimethylpropionamidine hydrochloride (0.14 g), prepared according to Example 1, was added to a solution of a 4:3 mixture of ethyl (RS)-4-dimethylamino-3-formyl-2-(1-methylethyl)-3-butenoate and ethyl (RS)-4-ethoxy-3-formyl- 2-(1-methylethyl)-3-butenoate (0.2 g), prepared according to the method of Example 10, in ethanol (2 cm3). A solution of sodium methoxide (0.06 g) in ethanol (1 cm3) was added to the stirred mixture, which was then heated at the reflux temperature for 2 hours. After cooling, the ethanol was evaporated under reduced pressure. The residual oil was purified by column chromatography on a silica gel support (Merck 7729), using dichloromethane, followed by dichloromethane containing 2% by volume ethyl acetate, as eluent, to give ethyl (RS)-2-[2-(2-methylprop-2-yl)pyrimidin-5-yl]-3-methylbutyrate (0.068 g) as a pale yellow oil.

1. customprepared
2. temperaturewas then heated at the reflux temperature for 2 hours
3. temperatureAfter cooling
4. customthe ethanol was evaporated under reduced pressure
5. customThe residual oil was purified by column chromatography on a silica gel support (Merck 7729)