Hydrochloric Acid → 4-(2,3-Difluoro-phenylcarbamoyl)-1-methanesulfonyl-1H-pyrrole-2-carboxylic acid methyl ester

Participants

Reaction Steps

To a solution of 1-methanesulfonyl-1H-pyrrole-2,4-dicarboxylic acid 2-methyl ester (290 mg, 1.17 mmol) in dry CH2Cl2 (5 mL) and DMF (2 drops) was added oxalyl chloride (220 mg, 1.73 mmol) at room temperature. The mixture was stirred for 1 hour and evaporated. The residue was dried on the vacuum pump for 4 hours and then dissolved in dry CH2Cl2 (5 mL). To this solution was added 2,3-difluoro-phenylamine (300 mg, 2.32 mmol) and triethylamine (240 mg, 2.37 mmol). The reaction mixture was stirred for another 1 hour then poured into 2N HCl solution. The aqueous solution was extracted with EtOAc and the combined organic layers were dried over MgSO4. After removal of solvent by evaporation, the residue was purified by flash column eluting with 20% EtOAc/hexanes to afford the title compound as a yellow solid (410 mg, 98%). MS (ES+): m/e=359.1 (M+H); LC/Method A/3.31 min.

Provenance & Evidence