反应详情

The product of stage (b) (32.2 g) was boiled under reflux in ethanol (200 ml) containing sulphuric acid (7 drops) for 2 hours. The solution was cooled, neutralised with triethylamine and reduced to half volume under vacuum. Addition to water and isolation through diethyl ether gave 34.4 g of crude title product as a yellow oil. This was dissolved in petroleum ether bp 40°-60° C. containing 5% diethyl ether, then filtered through a bed of aluminium oxide followed by elution with the same solvent mixture. This yielded 30.5 g of the pure product as a colourless oil.

1. temperatureThe solution was cooled