Methanesulfonic Acid → 2-(2-Bromophenyl)-1H-benzimidazole
Reaction equation
CS(O)(=O)=O.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[C:20]1([NH2:27])[CH:25]=[CH:24][CH:23]=[CH:22][C:21]=1[NH2:26].[Br:28][C:29]1[CH:37]=[CH:36][CH:35]=[CH:34][C:30]=1[C:31](O)=O.C(=O)([O-])[O-].[Na+].[Na+]>>[Br:28][C:29]1[CH:37]=[CH:36][CH:35]=[CH:34][C:30]=1[C:31]1[NH:27][C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][C:21]=2[N:26]=1Participants
6
Procedure
To a flask were added 80 g methanesulfonic acid and 8 g phosphorus pentoxide and the mixture was heated to 60 C under nitrogen until the solids had completely dissolved. To this solution was added 2.7 g 1,2-phenylene diamine and 5.0 g 2-bromobenzoic acid and the mixture was heated to 100 C for 30 minutes. The mixture was poured onto 300 ml ice water and basified with the addition of small portions of sodium carbonate. Following filtration of the solid and washing with water, the crude product was dissolved in 85 ml hot ethanol, filtered and 9 ml of water was added. After cooling to 5 C, the product was filtered and washed with 50% ethanol and dried, giving 3.85 g off-white solid.
Workup
- temperaturethe mixture was heated to 60 C under nitrogen until the solids
- dissolutionhad completely dissolved
- temperaturethe mixture was heated to 100 C for 30 minutes
- filtrationfiltration of the solid
- washwashing with water
- dissolutionthe crude product was dissolved in 85 ml hot ethanol
- filtrationfiltered
- addition9 ml of water was added
- temperatureAfter cooling to 5 C
- filtrationthe product was filtered
- washwashed with 50% ethanol
- customdried
Sources & evidence
- ORD record
- ord-cad03073d814444c874cd627afa7b4e7
- Source dataset
- uspto-grants-2011_09
- Patent number
- US08018639B2
Reaction notes
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