反应详情

温度

115 °C

0.64 g (0.92 mmol) of bistriphenylphosphinepalladium dichloride, 4.4ml (46 mmol) of 3-methyl-3-buten-1-yne and 24ml of triethylamine are added under nitrogen to a solution of 15.0 g (46 mmol) of 2,2-dimethyl-5-trifluoromethylsulfonyloxy-4H(1,3)benzodioxin-4-one in 150 ml of dimethylformamide. The mixture is heated at 115° C. for 0.5 h, a further 6.6 ml of 3-methyl-3-buten-1-yne are then added at this temperature in the course of 1 h and the reaction solution is subsequently stirred for 15 min. After cooling, it is poured into 500 ml of water containing phosphoric acid (pH 3) at 0° C. and extracted with methyl tert-butyl ether, and the combined organic phases are carefully washed with water and saturated sodium chloride solution, dried over sodium sulfate and concentrated. 14 g of a dark oil remain, which is chromatographed on silica gel using n-hexane/ethyl acetate. 7.0 g of colorless crystals are obtained, m.p. 60° C. (cf. Table 1, No. 1.009).

1. temperatureAfter cooling
2. extractionextracted with methyl tert-butyl ether
3. washthe combined organic phases are carefully washed with water and saturated sodium chloride solution
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated
6. customwhich is chromatographed on silica gel