反应详情

温度

-78 °C

830 mg (1.70 mmol) of the compound from Example 71A are dissolved in 50 ml of anhydrous dichloromethane and cooled to −78° C. At this temperature, 3.40 ml (3.40 mmol) of a 1 normal boron tribromide solution in dichloromethane are added dropwise such that the temperature does not exceed −65° C. The mixture is stirred at −78° C. for 2 h and then at RT for 2.5 h and kept at −20° C. for 15 h. At room temperature, the solution is carefully added to a saturated aqueous sodium bicarbonate solution. After phase separation, the aqueous phase is extracted three times with dichloromethane, and the combined organic phases are washed with saturated sodium chloride solution, dried over sodium sulphate, filtered and evaporated to dryness under reduced pressure. This gives 907 mg (69% of theory, purity according to LC-MS 61%) of the desired compound.

1. customdoes not exceed −65° C
2. waitat RT for 2.5 h
3. waitkept at −20° C. for 15 h
4. customAfter phase separation
5. extractionthe aqueous phase is extracted three times with dichloromethane
6. washthe combined organic phases are washed with saturated sodium chloride solution
7. dry with materialdried over sodium sulphate
8. filtrationfiltered
9. customevaporated to dryness under reduced pressure