Phosphorus oxychloride → 2-Chloro-7-(2,5-dimethyl-1H-pyrrol-1-yl)-1-methyl-1H-benzimidazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 239 mg (0.991 mmol) of 7-(2,5-dimethyl-1H-pyrrol-1-yl)-1-methyl-1,3-dihydro-2H-benzimidazol-2-one in 2 mL of phosphorus oxychloride was stirred at 85° C. for 4 hours. After cooling, phosphorus oxychloride was evaporated in vacuo. The residue was diluted with ice and neutralized by aqueous sodium hydroxide. The aqueous suspension was extracted with ethyl acetate (X2). The combined organic layer was washed with water (X1) and brine (X1), dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 10-20% ethylacetate/n-hexane gradient mixture to give 185 mg (72%) of the title compound.

Provenance & Evidence