N-methyl-2-pyrrolidone → t-Butyl 4-(5-chloro-1-(2-fluoro-4-(methylsulfonyl)phenyl)-2-oxo-1,2-dihydropyridin-4-yloxy)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A two liter round bottom flask was charged with tetrabutylammonium 4-(1-(t-butoxycarbonyl)piperidin-4-yloxy)-5-chloropyridin-2-olate (90 g, 158 mmol), NMP (500 mL), and 1,2-difluoro-4-(methylsulfonyl)benzene (30.3 g, 158 mmol). The mixture was heated to 80° C. under nitrogen for 12 hours. After cooling to room temperature, the reaction was diluted with ethyl acetate (500 mL) and distilled water (500 mL). The organic layer was separated, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. To the residue was added 500 mL of 20% ethyl acetate in diethyl ether and the mixture was stirred for 12 hours at room temperature. The slurry was then cooled to 4° C. and stirring was continued for additional 1 hour. The solid was collected by filtration and dried under vacuum for 4 hours at 45° C. to yield t-butyl 4-(5-chloro-1-(2-fluoro-4-(methylsulfonyl)phenyl)-2-oxo-1,2-dihydropyridin-4-yloxy)piperidine-1-carboxylate (58 g, 70% yield) as a white solid. 1H-NMR (CDCl3, 400 MHz) δ 7.85-7.89 (m, 1H), 7.61-7.64 (m, 1H), 7.32 (s, 1H), 6.02 (s, 1H), 4.57-4.63 (m, 1H), 3.59-3.69 (m, 2H), 3.44-3.55 (m, 2H), 3.11 (s, 3H), 1.83-2.05 (m, 4H), 1.48 (s, 9H); MS m/e 501.2 (M+H+).

Provenance & Evidence