Hydrochloric Acid → 1,3-dihydro-1-(3-hydroxypropyl)-5-methyl-2H-benzimidazol-2-one

Participants

Reaction Steps

To a stirred and cooled solution of 54 parts of 3-[(2-amino-4-methylphenyl)amino]-1-propanol in 30 parts of hydrochloric acid solution 10% and 200 parts of water is added dropwise a solution of 28 parts of potassium cyanate in 50 parts of water at a temperature below 10° C. Upon completion, stirring is continued first for 1 hour at room temperature and further for 24 hours at reflux temperature. After cooling to room temperature, the product is extracted with trichloromethane. The extract is washed with a hydrochloric acid solution 5%, dried, filtered and evaporated. The residue is crystallized from 4-methyl-2-pentanone, yielding 19.5 parts (31%) of 1,3-dihydro-1-(3-hydroxypropyl)-5-methyl-2H-benzimidazol-2-one; mp. 114.1° C.

Provenance & Evidence