反应详情

温度

0 °C

N-Iodosuccinimide (3.52 g, 15.6 mmol) was added portionwise to a solution of methyl 4-cyclobutyl-2-methylbenzoate (compound 152.2, 3.2 g, 15.6 mmol) in concentrated sulfuric acid (25 ml) at 0° C. The mixture was stiffed at 0° C. for 30 min and at RT for 2 hours. The mixture turned very thick. The mixture was cooled to 0° C. again and MeOH (30 ml) was added. The mixture was heated at 60° C. for 2 hours. The methanol was removed under reduced pressure and the residue was poured into ice water (100 ml). The mixture was extracted with EtOAc (2×). The combined organic layers were washed with brine, then aq. 1N NaHCO3 (note-significant gas evolution), dried (Na2SO4) and concentrated. The residue was purified using column (silica gel) chromatography (hexanes:EtOAc 30:1 to 20:1). Yield: 4.17 g, light yellow oil, 81%. 1H NMR (400 MHz, Chloroform-d) δ 8.33 (s, 1H), 7.14 (s, 1H), 3.87 (s, 3H), 3.67-3.54 (m, 1H), 2.57 (s, 3H), 2.51-2.40 (m, 2H), 2.14-1.97 (m, 3H), 1.82-1.79 (m, 1H).

1. temperatureThe mixture was heated at 60° C. for 2 hours
2. customThe methanol was removed under reduced pressure
3. additionthe residue was poured into ice water (100 ml)
4. extractionThe mixture was extracted with EtOAc (2×)
5. washThe combined organic layers were washed with brine
6. dry with materialaq. 1N NaHCO3 (note-significant gas evolution), dried (Na2SO4)
7. concentrationconcentrated
8. customThe residue was purified