Methane → Domperidone

Participants

Reaction Steps

10.2 parts of 5-chloro-1-{1-[3-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)propyl]-4-piperidinyl}-1,3-dihydro-2H-benzimidazol-2-one are converted into the (+)-2,3-dihydroxybutanedioate salt in 100 parts of water at reflux temperature. The solution is treated for 10 minutes with a mixture of 0.5 parts of activated charcoal and 0.2 parts of hyflo. The latter is filtered off over hyflo and the filtrate is cooled till an oily precipitate is formed. The oily product solidifies upon heating for a while. The whole is allowed to cool to room temperature and stirred for 3 hours at this temperature. The product is filtered off, washed with water and dried in vacuo for 18 hours at 60° C, yielding 10.24 parts (85.3%) of 5-chloro-1-{1-[3-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)propyl]-4-piperidinyl}-1,3-dihydro-2H-benzimidazol-2-one hemi-[R-(R*,R*)](+)-2,3-dihydroxybutanedioate hydrate; mp. 184.1° C; [α] = + 5.13° (c = 1% CH3OH).

Provenance & Evidence