Phosphorus oxychloride → 2-chloro-6-(trifluoromethyl)-1H-benzimidazole
Reaction equation
[F:1][C:2]([F:14])([F:13])[C:3]1[CH:12]=[CH:11][C:6]2[NH:7][C:8](=O)[NH:9][C:5]=2[CH:4]=1.O=P(Cl)(Cl)[Cl:17]>>[Cl:17][C:8]1[NH:9][C:5]2[CH:4]=[C:3]([C:2]([F:14])([F:13])[F:1])[CH:12]=[CH:11][C:6]=2[N:7]=1Participants
3
Procedure
A solution of the dihydrobenzoimidazol-2-one from step (b) above (2.02 g, 10 mmol) in POCl3 (30 mL) was heated at 95° C. for 16 h. The reaction mixture was cooled to room temperature, the solvent was removed in vacuo and the resulting oily residue subjected to azeotropic distillation with toluene (3×50 mL) at 50° C. The crude product was dissolved in EtOAc (50 mL), washed with brine (10 mL) then dried over Na2SO4 and filtered. The solvent was removed in vacuo and the residue was recrystallized from EtOAc/hexane to give the title compound.
Workup
- customthe solvent was removed in vacuo
- distillationthe resulting oily residue subjected to azeotropic distillation with toluene (3×50 mL) at 50° C
- dissolutionThe crude product was dissolved in EtOAc (50 mL)
- washwashed with brine (10 mL)
- dry with materialthen dried over Na2SO4
- filtrationfiltered
- customThe solvent was removed in vacuo
- customthe residue was recrystallized from EtOAc/hexane
Sources & evidence
- ORD record
- ord-5c21a7033d1d4fd2aedf69f95dde0f89
- Source dataset
- uspto-grants-2011_09
- Patent number
- US08026241B2
Reaction notes
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