反应详情

The product of step (a) (1.75 g), and diethyl oxalate (4.38 g) dissolved in dry ethanol (50 mls) was added to sodium ethoxide solution (prepared by the addition of sodium (0.35 g), to dry ethanol (50 mls) with stirring. The reaction mixture was stirred under reflux for 1 hr, cooled, poured into ethyl acetate and dilute hydrochloric acid and the organic layer separated, washed well with water and dried. The solvent was evaporated and the residue treated with ethanol saturated with hydrogen chloride gas (100 mls) and refluxed for 10 mins. The reaction mixture was cooled, poured into water, and the precipitated product collected by filtration, washed well with water and dried to give 2.5 g of product. A recrystallisation from ethanol gave 1.25 g, mp 168°-171°.

1. stirringThe reaction mixture was stirred
2. temperatureunder reflux for 1 hr
3. temperaturecooled
4. customthe organic layer separated
5. washwashed well with water
6. customdried
7. customThe solvent was evaporated
8. additionthe residue treated with ethanol saturated with hydrogen chloride gas (100 mls)
9. temperaturerefluxed for 10 mins
10. temperatureThe reaction mixture was cooled
11. additionpoured into water
12. filtrationthe precipitated product collected by filtration
13. washwashed well with water
14. customdried