反应详情

温度

0 °C

A solution of 21.6 g of the compound of Step A above in 48 ml of Claisen's alkali solution (solution of 21 g of KOH in 15 ml of water, made up to 60 ml with methanol) is heated at reflux for 4 hours. The reaction mixture is then diluted with 50 ml of water and poured into 75 ml of 15.5% hydrochloric acid solution cooled to 0° C. with stirring. The white precipitate formed is then filtered off over a Buchner funnel and then washed with water and dried under a phosphoric vacuum. The dry residue obtained is dissolved in a solution of ethanol and water (80:20, v/v) at boiling. After cooling to 0° C., 13.7 g of the expected product are obtained.

1. temperatureis heated
2. temperatureat reflux for 4 hours
3. customThe white precipitate formed
4. filtrationis then filtered off over a Buchner funnel
5. washwashed with water
6. customdried under a phosphoric vacuum
7. customThe dry residue obtained
8. temperatureAfter cooling to 0° C.