反应详情

A solution of 6.57 g of 2-[1-(2,4-dimethoxyphenyl)hexyl]malonic acid [prepared as described in step (i) above] in 60 ml of xylene was heated under reflux for 3 hours. At the end of this time, the solvent was removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through 100 g of silica gel, using a gradient elution method, with mixtures of methylene chloride and methanol ranging from 1:0 to 10:1 by volume as the eluent, to give 4.55 g (a total yield of 74% over the two steps) of the title compound as crystals, melting at 52-53° C. (from hexane).

1. temperatureunder reflux for 3 hours
2. customAt the end of this time, the solvent was removed by distillation under reduced pressure
3. customthe resulting residue was purified by column chromatography through 100 g of silica gel
4. washa gradient elution method