Hydrogen Bromide → 1-(3-bromopropyl)-5,6-dichloro-1,3-dihydro-2H-benzimidazol-2-one
Reaction equation
[Cl:1][C:2]1[C:15]([Cl:16])=[CH:14][C:5]2[N:6]([CH2:10][CH2:11][CH2:12]O)[C:7](=[O:9])[NH:8][C:4]=2[CH:3]=1.[BrH:17]>O>[Br:17][CH2:12][CH2:11][CH2:10][N:6]1[C:5]2[CH:14]=[C:15]([Cl:16])[C:2]([Cl:1])=[CH:3][C:4]=2[NH:8][C:7]1=[O:9]Participants
4
Procedure
A mixture of 57.5 parts of 5,6-dichloro-1,3-dihydro-1-(3-hydroxypropyl)-2H-benzimidazol-2-one and 450 parts of a hydrobromic acid solution 48% in water is stirred and refluxed for 2.50 hours. The reaction mixture is cooled and water is added. The precipitated product is filtered off, stirred in 700 parts of water, filtered off again and dried in vacuo, yielding 59 parts (81%) of 1-(3-bromopropyl)-5,6-dichloro-1,3-dihydro-2H-benzimidazol-2-one; mp. 198.1° C.