反应详情

温度

0 °C

18 g of the product of Step A and 400 ml of dichloromethane were mixed together under nitrogen and the mixture was cooled to 0° C. 150 ml of a molar solution of boron tribromide in dichloromethane were added and the mixture stood for one night at ambient temperature. It was concentrated, cooled again to 0° C. and 250 ml of a normal solution of hydrochloric acid were added. The crystallized product was separated out, washed with water, dried then crystallized from an isopropanol--water mixture (1-2) to obtain 12 g of the expected product.

1. waitthe mixture stood for one night at ambient temperature
2. concentrationIt was concentrated
3. temperaturecooled again to 0° C.
4. addition250 ml of a normal solution of hydrochloric acid were added
5. customThe crystallized product was separated out
6. washwashed with water
7. customdried
8. customthen crystallized from an isopropanol