methyl 1,4-dimethyl-1H-benzimidazole-5-carboxylate → 1,4-dimethyl-1H-benzimidazole-5-carboxylic acid

Temperature

60 °C

A mixture of the methyl 1,4-dimethyl-1H-benzimidazole-5-carboxylate (78 mg, 0.38 mmol) in methanol (2 mL) and 5% aqueous sodium hydroxide solution (2 mL) was stirred at 60° C. for one hour. The reaction mixture was concentrated, diluted with water (10 mL) and the pH adjusted to 4 then saturated with solid sodium chloride. The aqueous mixture was extracted ethyl acetate (3×10 mL) and the combined extract was washed with water (15 mL), brine (15 mL), dried over sodium sulfate, filtered and concentrated to give 1,4-dimethyl-1H-benzimidazole-5-carboxylic acid (46 mg, 63% yield), MS (EI) for C10H10N2O2: 191 (MH+).

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with water (10 mL)
3. extractionThe aqueous mixture was extracted ethyl acetate (3×10 mL)
4. extractionthe combined extract
5. washwas washed with water (15 mL), brine (15 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-cfd0813acb6a4e5ca95f026da5ebcd78

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08012956B2