反应详情

温度

72.5 °C

To a solution of 3-benzyloxy-6-methyl-4-oxo-4H-pyran-2-carboxylic acid cyclohexylamide (1.40 g, 4.1 mmol) in 5 ml of methanol, methylamine solution (9 ml of 2M solution in methanol, 16 mmol) was added. The resulting solution was stirred at 70 to 75° C. for overnight under the pressure in a sealed tube. The solvent was removed under reduced pressure gave light yellow solid as a crude product. The material was purified by column chromatography (elution gradient: 100% ethyl acetate to 25% methanol in ethyl acetate) to give the titled compound as white solid (1.20 g, 83.0%). M.p. 258-260° C.; 1H-NMR (CDCl3, 400 MHz) δ 1.26-1.45 (m, 6H, cyclohexyl-H), 1.79 (m, 2H, cyclohexyl-H), 1.95 (m, 2H, cyclohexyl-H), 2.41 (s, 3H, CH3), 3.82 (s, 3H, NCH3), 3.95 (m, 1H, CH), 5.13 (s, 2H, CH2), 7.19 (s, 1H, CH), 7.36 (m, 3H, ArH), 7.43 (m, 2H, ArH), 8.50 (br, 1H, NH); MS (m/z) 355 (M++1).

1. customThe solvent was removed under reduced pressure
2. customgave light yellow solid as a crude product
3. customThe material was purified by column chromatography (elution gradient: 100% ethyl acetate to 25% methanol in ethyl acetate)