Dichloromethane → 1,3-dihydro-1-(3-hydroxypropyl)-5-methyl-2H-benzimidazol-2-one methanesulfonate

Participants

Reaction Steps

To a stirred solution of 18.5 parts of 1,3-dihydro-1-(3-hydroxypropyl)-5-methyl-2H-benzimidazol-2-one in 325 parts of dichloromethane are added 11.9 parts of N,N-diethylethanamine. Then there are added dropwise (slowly) 11.5 parts of methanesulfonyl chloride. Upon completion, stirring is continued for 1 hour at reflux temperature. After cooling, the reaction mixture is washed with water, dried, filtered and evaporated. The solid residue is crystallized from 4-methyl-2-pentanone, yielding 15 parts (58%) of 1,3-dihydro-1-(3-hydroxypropyl)-5-methyl-2H-benzimidazol-2-one methanesulfonate; mp. 125° C.

Provenance & Evidence