反应详情

A mixture of the product of step (b) (1.6 g; 4.8426 mmole) and diethyl oxalate (5.7 g; 39.041 mmole; 5.3 ml) in dry dimethylformamide (60 ml) was added slowly to a stirring suspension of ether washed sodium hydride (0.29 g; 12.0808 mmole) in dry dimethylformamide (10 ml) under nitrogen. After the addition, the mixture was allowed to stir for 7 hours. The reaction mixture was poured onto ice and was then acidified with dilute hydrochloric acid. The pH of the mixture was adjusted to about 6 before being extracted into chloroform. This was washed with water, dried and evaporated to give a yellow solid. The solid was taken up in ethanolic hydrogen chloride (50 ml) and heated to reflux on the steambath for 3 hours. The solution was cooled, treated with water and then concentrated. The pH of the mixture was adjusted to about 7 and then extracted into chloroform. The extract was washed with water, dried and evaporated, to give a brown solid.

1. additionAfter the addition
2. additionThe reaction mixture was poured onto ice
3. extractionbefore being extracted into chloroform
4. washThis was washed with water
5. customdried
6. customevaporated
7. customto give a yellow solid
8. temperatureheated
9. temperatureto reflux on the steambath for 3 hours
10. temperatureThe solution was cooled
11. concentrationconcentrated
12. extractionextracted into chloroform
13. washThe extract was washed with water
14. customdried
15. customevaporated
16. customto give a brown solid