Fumaric Acid → 1H-Benzimidazole, 2-((4-methyl-1-piperazinyl)methyl)-1-(2-propoxyethyl)-, (E)-2-butenedioate (1:2)
Reaction equation
[CH2:1]([O:4][CH2:5][CH2:6][N:7]1[C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=2[N:9]=[C:8]1[CH2:16][N:17]1[CH2:22][CH2:21][N:20]([CH3:23])[CH2:19][CH2:18]1)[CH2:2][CH3:3].[C:24]([OH:31])(=[O:30])/[CH:25]=[CH:26]/[C:27]([OH:29])=[O:28]>>[C:24]([OH:31])(=[O:30])/[CH:25]=[CH:26]/[C:27]([OH:29])=[O:28].[C:24]([OH:31])(=[O:30])/[CH:25]=[CH:26]/[C:27]([OH:29])=[O:28].[CH2:1]([O:4][CH2:5][CH2:6][N:7]1[C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=2[N:9]=[C:8]1[CH2:16][N:17]1[CH2:22][CH2:21][N:20]([CH3:23])[CH2:19][CH2:18]1)[CH2:2][CH3:3]Participants
3
Procedure
The above-obtained pale yellow solid [i.e. 1-(2-n-propoxyethyl)-2-(4-methyl-1-piperazinyl)methylbenzimidazole] (3.5 g) is treated with fumaric acid (2.57 g), and the crude crystal thus obtained is recrystallized from ethyl acetate-ethanol to give 1-(2-n-propoxyethyl)-2-(4-methyl-1-piperaziny)methylbenzimidazole difumarate (3.49 g) as colorless crystals, m.p. 160.5°-161.5° C.
Workup
- customthe crude crystal thus obtained
- customis recrystallized from ethyl acetate-ethanol