反应详情

157 g (174 mmol) of the compound from Example 64A (alternative synthesis) are dissolved in 1.44 l of dichloromethane. At 15-20° C., 453 ml (5.32 mol) of concentrated hydrochloric acid are added dropwise, and the mixture is stirred at room temperature for 1 h. The phases are separated, the organic phase is discarded. The aqueous phase is washed twice with dichloromethane. Dichloromethane is then added to the aqueous phase, and the mixture is adjusted with cooling to pH=10 using 1:1 dilute aqueous sodium hydroxide solution. The phases are separated, and the organic phase is washed twice with water and then dried over sodium sulphate. After filtration, the filtrate is concentrated to dryness under reduced pressure. The residue is triturated with acetone, cooled to 10° C., filtered off at this temperature and washed with cold acetone. Drying gives 75 g (85% of theory) of the desired product.

1. customThe phases are separated
2. washThe aqueous phase is washed twice with dichloromethane
3. additionDichloromethane is then added to the aqueous phase
4. temperaturewith cooling to pH=10
5. customThe phases are separated
6. washthe organic phase is washed twice with water
7. dry with materialdried over sodium sulphate
8. filtrationAfter filtration
9. concentrationthe filtrate is concentrated to dryness under reduced pressure
10. customThe residue is triturated with acetone
11. temperaturecooled to 10° C.
12. filtrationfiltered off at this temperature
13. washwashed with cold acetone
14. customDrying