反应详情

Racemic 19 (62.7 g, 314.4 mmol) is dissolved in EtOAc (300 ml) and a solution of L-(−)-O,O′-Dibenzoyl tartaric acid (56.3 g, 157.2 mmol) in EtOAc (450 ml) is added. The formed solid is filtered off, washed with cold EtOAc and dried. It is then re-crystallized from hot methanol (400 ml). The crystals are collected and the free base is liberated by treatment with 1N—NaOH and extraction with ether.

1. filtrationThe formed solid is filtered off
2. washwashed with cold EtOAc
3. customdried
4. customIt is then re-crystallized from hot methanol (400 ml)
5. customThe crystals are collected
6. extractionthe free base is liberated by treatment with 1N—NaOH and extraction with ether