Methane → Oxatomide monohydrate

Participants

Reaction Steps

50 Parts of 1-{3-[4-(diphenylmethyl)-1-piperazinyl]propyl}-1,3-dihydro-2H-benzimidazol-2-one are dissolved in 200 of 2-propanol while stirring and heating. The solution is stirred with 2.5 parts of activated charcoal. The latter is filtered off and upon cooling to room temperature, the product is crystallized. It is filtered off and converted into the hydrochloride salt in 2-propanol. The salt is filtered off, washed twice with 2-propanol and dried overnight in vacuo at 60° C. It is dissolved in 320 parts of methanol and the free base is liberated in the conventional manner with a sodium hydroxide solution 5N. The whole is concentrated to a volume of about 150 parts. The precipitated product is filtered off, washed with 500 parts of water and dissolved in 120 parts of 2-propanol. The solution is stirred and heated with 1 part of activated charcoal. The latter is filtered off over hyflo while hot. The filtrate is cooled to room temperature while stirring. The precipitated product is filtered off and dried over week-end in vacuo at 60° C., yielding 21.49 parts of 1-{3-[4-(diphenylmethyl)-1-piperazinyl]propyl}-1,3-dihydro-2H-benzimidazol-2-one hydrate; mp. 156.6° C.

Provenance & Evidence