反应详情

A solution of the compound obtained in Step A (0.244 mol) and SnCl2.2H2O (1.0 mol) in ethanol (300 ml) is stirred at reflux for 20 minutes. The solution is brought to 0° C. and made alkaline at pH=10-12 with aqueous sodium hydroxide solution; 500 ml of DCM are added and the emulsion obtained is filtered over Celite. The filtrate is then extracted with DCM (2×300 ml); the organic phases are combined. The organic phase obtained is washed with water and with saturated aqueous NaCl solution, dried over sodium sulphate and then filtered. The filtrate obtained is evaporated to dryness to yield the title product, which is used directly in the next Step.

1. temperatureat reflux for 20 minutes
2. customis brought to 0° C.
3. customthe emulsion obtained
4. filtrationis filtered over Celite
5. extractionThe filtrate is then extracted with DCM (2×300 ml)
6. customThe organic phase obtained
7. washis washed with water and with saturated aqueous NaCl solution
8. dry with materialdried over sodium sulphate
9. filtrationfiltered
10. customThe filtrate obtained
11. customis evaporated to dryness