反应详情

1.58 g of 4-[3-chloro-4-(ethoxycarbonylmethoxy)phenyl]-4-oxobutyric acid [prepared as described in step (a) above] was dissolved in 10 ml of ethanol and 0.31 g of 80% v/v aqueous hydrazine hydrate was added thereto, whilst ice-cooling. The mixture was stirred, with ice-cooling, for 5 minutes, and then heated under reflux for 3 hours, after which ethyl acetate was added thereto. The mixture was then cooled to room temperature and the resulting precipitate was recrystallized from a mixture of ethyl acetate and hexane, to give 1.49 g of the title compound, having the same characteristics as the product of Example 1.

1. temperaturewhilst ice-cooling
2. temperaturecooling, for 5 minutes
3. temperatureheated
4. temperatureunder reflux for 3 hours
5. customthe resulting precipitate was recrystallized from a mixture of ethyl acetate and hexane