Hydrochloric Acid → HCID 20385586, compound

Participants

Reaction Steps

A solution of 7 parts of 5-chloro-1-[1-{3-[1,3-dihydro-3-(1-methylethenyl)-2-oxo-2H-benzimidazol-1-yl]-2-methylpropyl}-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one in 120 parts of ethanol is acidified with 2-propanol, previously saturated with gaseous hydrogen chloride. The whole is boiled for 5 minutes. The reaction mixture is evaporated and the residue is taken up in water. The mixture is alkalized with a concentrated ammonium hydroxide solution. The product is extracted with trichloromethane. The extract is dried, filtered and evaporated. The residue is crystallized from a mixture of 4-methyl-2-pentanone and ethanol. The product is filtered off and dried, yielding 1.3 parts (19.7%) of 5-chloro-1-{1-[3-(1,3-dihydro-2-oxo-2H-benzimidazol-1-yl)-2-methylpropyl]-4-piperidinyl}-1,3-dihydro-2H-benzimidazol-2-one; mp. 244° C.

Provenance & Evidence