1,2-Dibromoethane → 3,4-Dihydro-7-(4-methyl-1H-imidazol-1-yl)pyrido[2,1-c][1,4]oxazine-1,6-dione

Participants

Reaction Conditions

Reaction Steps

N,N-Dimethylformamide (850 mL) was added to a mixture of 5-(4-methyl-1H-imidazol-1-yl)-6-oxo-1,6-dihydropyridine-2-carboxylic acid hydrochloride salt (C3) (65 g, 250 mmol), 1,2-dibromoethane (52.5 g, 280 mmol) and cesium carbonate (124 g, 381 mmol), and the reaction mixture was heated to 90° C. for 6 hours. After allowing the reaction to cool to room temperature, the mixture was filtered through Celite, and the filtrate was concentrated in vacuo. The residue was dissolved in dichloromethane (500 mL), washed with saturated aqueous sodium chloride solution (100 mL), washed with water (50 mL), dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting solid was washed with acetonitrile to provide the product. Yield: 46.5 g, 190 mmol, 76%. 1H NMR (400 MHz, CDCl3) δ 2.30 (d, J=0.8 Hz, 3H), 4.38-4.42 (m, 2H), 4.66-4.70 (m, 2H), 7.15-7.17 (m, 1H), 7.43 (AB quartet, JAB=7.7 Hz, ΔνAB=33.4 Hz, 2H), 8.33 (d, J=1.4 Hz, 1H).

Provenance & Evidence