Isopropanol → 3-Bromo-1-phenyl-5-(pyridin-2-yl)-1,2-dihydropyridin-2-one

Participants

Reaction Conditions

Reaction Steps

5-(2-Pyridyl)-1-phenyl-1,2-dihydropyridine-2-one (300 g), N-bromosuccinimide (236.5 g) and N,N-dimethylformamide (1.8 L) were placed in a 10-L reactor, and the reaction mixture was stirred at 30° C. (external temperature) in a nitrogen stream for 3 hours and 15 minutes. 2-Propanol (4.2 L) was added dropwise to the reaction mixture over a period of 9 minutes, followed by adding thereto water (2.1 L) over a period of 7 minutes. The resulting mixture was heated at 85° C. (external temperature) with stifling. After confirming the dissolution of the contents, the resulting solution was stirred at an external temperature of 55° C. for 1 hour. Thereafter, the solution was stirred at 40° C. (external temperature) for another 22 minutes, at 30° C. (external temperature) for further another 23 minutes, and then at 10° C. (external temperature) for still another 15 hours and 15 minutes. The reaction mixture was filtered and the precipitate was washed with 50% 2-propanol-water (2.4 L) and then dried under reduced pressure (60° C., 6 hours) to obtain 341.45 g of 3-bromo-5-(2-pyridyl)-1-phenyl-1,2-dihydropyridine-2-one. Yield: 86.4%. 1H NMR (400 MHz, CDCl3) δ 8.59-8.56 (m, 1H), 8.50 (d, 1H), 8.18 (d, 1H), 7.72 (td, 1H), 7.53-7.41 (m, 6H), 7.20 (ddd, 1H).

Provenance & Evidence