Dimethylformamide → 5-Bromo-2-chloro-3-pyridinecarbonyl chloride

Participants

Reaction Conditions

Reaction Steps

5-Bromo-2-chloro-N-methoxy-N-methylnicotinamide. To a mixture of 5-bromo-2-chloronicotinic acid (6 g, 25.5 mmol) in thionyl chloride (30 mL) was added a drop of N,N-dimethylformamide, and the reaction mixture was heated at 80° C. for 2 h. The mixture was cooled to room temperature, and concentrated to give crude 5-bromo-2-chloronicotinoyl chloride. A solution of O,N-dimethyl-hydroxylamine hydrochloride salt (3.45 g, 35.6 mmol) and triethylamine (7.48 g, 74.1 mmol) in dichloromethane (80 mL), and a solution of the above 5-bromo-2-chloronicotinoyl chloride in dichloromethane (20 mL) were added, and the reaction mixture was stirred overnight. The mixture was poured into water, and extracted with dichloromethane (50 mL×3). The combined organic layer was concentrated under reduced pressure, and purified on silica gel column (eluting with 5-10% ethyl acetate in petroleum ether) to give 5-bromo-2-chloro-N-methoxy-N-methylnicotinamide as a solid (6.2 g, 71.4% yield). 1H NMR (400 MHz, DMSO-d6) δ (ppm) 8.65 (s, 1H), 8.39 (s, 1H), 3.49 (s, 3H), 3.30 (s, 3H).

Provenance & Evidence