反应详情

温度

170 °C

To a solution of 3-cyclohexylaminobut-2-enoic acid methyl ester (1.12 g, 5.72 mmol) in bromobenzene (20 mL) was added 2-methylmalonic acid bis-(2,4,6-trichloro-phenyl)ester (2.71 g, 5.72 mmol) and the reaction mixture was heated at 170° C. for 3 h. The reaction mixture was cooled to room temperature, and concentrated under reduced pressure. Purification by flash column chromatography (silica, eluent methylene chloride to 94:6 methylene chloride/MeOH) and recrystallization from hot MeOH provided methyl 1-cyclohexyl-4-hydroxy-2,5-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxylate as pale yellow crystals (0.34 g, 21%): 1H NMR (500 MHz, DMSO-d6) δ 9.82 (s, 1H), 4.00-3.90 (m, 1H), 3.76 (s, 3H), 2.75-2.60 (m, 2H), 2.31 (s, 3H), 1.81 (s, 3H), 1.80-1.70 (m, 2H), 1.65-1.50 (m, 3H), 1.40-1.20 (m, 2H), 1.15-1.05 (m, 1H).

1. temperatureThe reaction mixture was cooled to room temperature
2. concentrationconcentrated under reduced pressure
3. customPurification
4. customby flash column chromatography (silica, eluent methylene chloride to 94:6 methylene chloride/MeOH) and recrystallization from hot MeOH