Thionyl Chloride → 1-(2-chloroethyl)-1,3-dihydro-5-methyl-2H-benzimidazol-2-one

Participants

Reaction Steps

To a stirred mixture of 26 parts of 1,3-dihydro-1-(2-hydroxyethyl)-5-methyl-2H-benzimidazol-2-one and 390 parts of trichloromethane are added dropwise 48 parts of sulfinyl chloride at room temperature. Upon completion, stirring is continued for 5 hours at reflux. The reaction mixture is evaporated. The oily residue is heated with 2,2'-oxybispropane and a small amount of 2-propanol and the whole is stirred with activated charcoal. The latter is filtered off and the filtrate is stirred at room temperature till all the product is precipitated. It is filtered off and dried, yielding 12 parts (42%) of 1-(2-chloroethyl)-1,3-dihydro-5-methyl-2H-benzimidazol-2-one; mp. 120° C.

Provenance & Evidence