Potassium cyanate → 5,6-dichloro-1,3-dihydro-1-(3-hydroxypropyl)-2H-benzimidazol-2-one

Participants

Reaction Steps

To a stirred mixture of 31.2 parts of 3-[(2-amino-4,5-dichlorophenyl)amino]-1-propanol hydrochloride in 200 parts of water is added dropwise, during a 15 minutes-period, a solution of 10.6 parts of potassium cyanate in 50 parts of water at a temperature between 15° and 20° C. Upon completion, stirring is continued first for 20 minutes at room temperature and further for 20 hours at reflux. The reaction mixture is allowed to cool over week-end to room temperature. The precipitated product is filtered off and boiled in trichloromethane. The undissolved part is filtered off and boiled in 4 -methyl-2-pentanone. After cooling, the product is filtered off and dried, yielding 14.5 parts (48%) of 5,6-dichloro-1,3-dihydro-1-(3-hydroxypropyl)-2H-benzimidazol-2-one; mp. 174.7° C.

Provenance & Evidence