反应详情

温度

50 °C

The product of Example 1A (1.0 g, 4.90 mmole) was weighed into a 100 ml round bottom flask and pyridium p-toluenesulfonate (0.37 g, 1.47 mmole) was added. The flask was placed on high vacuum overnight. Para-xylene (50 ml) was added followed by triethylamine (0.68 ml, 4.9 mmole). The mixture was rapidly stirred at 50° C. to give an almost clear solution. A solution of 3-methylene-cyclobutanecarbonyl chloride (0.64 g, 4.9 mmole) (prepared according to literature procedure, JACS, 1959, 81, 2723-2728) in 10 ml xylene was then added dropwise over 15 minutes. The temperature was raised to 140° C. for 7 hours. The mixture was cooled to room temperature, followed by the addition of ethyl acetate (100 ml). The resulting solution was washed with saturated sodium bicarbonate, and the organic layer was dried (Na2SO4), and concentrated to give an oil. The crude product was purified by chromatography (20% hexane in dichloromethane) to give the title compound (1.03 g, 75%). 1H NMR (300 MHz, CDCl3) δ ppm 7.98 (d, J=2.03 Hz, 1H), 7.83 (d, J=8.82 Hz, 1H), 7.55 (dd, J=8.82, 2.03 Hz, 1H), 4.83-4.98 (m, 2H), 3.83-4.04 (m, 1H), 3.10-3.35 (m, 4H). MS: (M+H)+=279/281.

1. customwas placed on high vacuum overnight
2. customto give an almost clear solution
3. temperatureThe temperature was raised to 140° C. for 7 hours
4. temperatureThe mixture was cooled to room temperature
5. washThe resulting solution was washed with saturated sodium bicarbonate
6. dry with materialthe organic layer was dried (Na2SO4)
7. concentrationconcentrated
8. customto give an oil
9. customThe crude product was purified by chromatography (20% hexane in dichloromethane)