反应详情

41.3 g (0.13 mol) of the compound from Example IV are dissolved in 325 ml of toluene and heated to reflux with 33.4 g (156 mmol) of diphenyl carbonate and 21.7 g (143 mmol) of 1,8-diazabicyclo-[5.4.0]-undec-7-ene for 30 min. The mixture is cooled and treated with 300 ml of water and 150 ml of ethyl acetate. The aqueous phase is extracted with 300 ml of ethyl acetate and the combined organic phases are washed twice with 200 ml of 0.1M NaOH and once with 200 ml of saturated sodium chloride solution, dried using sodium sulphate and concentrated in vacuo. The residue which remains is chromatographed in a column (φ 20 cm) on 1.6 kg of silica gel 230-400 mesh using a mixture of petroleum ether/ethyl acetate (3:1) to (1:1).

1. temperatureheated
2. temperatureThe mixture is cooled
3. extractionThe aqueous phase is extracted with 300 ml of ethyl acetate
4. washthe combined organic phases are washed twice with 200 ml of 0.1M NaOH and once with 200 ml of saturated sodium chloride solution
5. customdried
6. concentrationconcentrated in vacuo
7. customThe residue which remains is chromatographed in a column (φ 20 cm) on 1.6 kg of silica gel 230-400 mesh
8. additiona mixture of petroleum ether/ethyl acetate (3:1) to (1:1)