2-Chlorophenyl-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)acetamide → (S)-2-(2-chloro-phenyl)(4,5,6,7-tetrahydrothieno[3,2-c]pyrid-5-yl)acetamide (+)-camphor sulfonic acid salt

Participants

Reaction Steps

A solution of 5 g (16.31 mmol) of (±)-(2-chloro-phenyl)-(6,7-dihydro-4H-thieno[3,2-c]pyrid-5-yl) acetamide (prepared as given in Examples 10-15) and 4.15 g (16.2 mmol) (1S)-(+)-camphor-10-sulphonic acid monohydrate in 100 mL acetone was kept warm for 20 hrs followed by storing it in temperature below 10° C. A few crystals appeared, the mother liquor was concentrated further and repeated recrystallization, followed by storage in cold condition for few days gave 3.1 g (70% yield) of (S)-2-(2-chloro-phenyl)-(4,5,6,7-tetrahydrothieno[3,2-c]pyrid-5-yl)acetamide (+)-camphor sulfonic acid salt. The salt was further purified by recrystallization in acetone, until constant specific optical rotation was obtained.

Provenance & Evidence