Oxalyl chloride → 6-Chloro-5-fluoro-2-(2-fluoro-4-trimethylsilanyl-phenylamino)-nicotinic acid methyl ester

Participants

Reaction Steps

To a suspension of 6-chloro-5-fluoro-2-(2-fluoro-4-trimethylsilanyl-phenylamino)-nicotinic acid (7.6 g, 21.3 mmol) in dichloromethane (100 mL) and DMF (1 mL) was added oxalyl chloride (9.1 mL, 106.4 mmol) dropwise over 20 minutes. The reaction mixture was stirred at reflux for 18 hours and then concentrated in vacuo and the residue azeotroped with toluene. The resultant residue was taken up in cold (0° C.) methanol (100 mL). The resultant solution was heated at reflux for 1 hour, then cooled to room temperature and filtered. The precipitate was washed with cold methanol and dried under vacuum at 45° C. to give the title compound as a yellow solid (7.3 g, 92%). LCMS (method B): RT=5.38 min, [M+H]+=371.

Provenance & Evidence