反应详情

58.0 g (167.8 mmol) of 2-chloro-4-methylsulfonyl-3-(3a,4,5,6a-tetrahydrofuro[3,2-d]isoxazol-3-yl)-benzoate are dissolved in 600 ml of dichloromethane, and 31.94 g (251.6 mmol) of oxalyl chloride and three drops of dimethylformamide are added at room temperature. After the evolution of gas has ceased (approx. 2 hours), the mixture is refluxed for a further hour. It is subsequently concentrated, and redissolved in 300 ml of dichloromethane. At 0-5° C., a mixture of 19.5 g (173.9 mmol) of 1,3-cyclohexanedione and 17.6 g (173.9 mmol) of triethylamine in 200 ml of dichlormethane is added dropwise. The mixture is stirred for 2 hours and then washed in succession with sodium carbonate solution and sodium chloride solution, and the organic phase is then dried over magnesium sulfate. After removal of the solvent, 64.5 g (87% of theory) of crude 3-oxocyclohex-1-enyl 2-chloro-4-methyl-sulfonyl-3-(3a,4,5,6a-tetrahydrofuro[3,2-d]isoxazol-3-yl)benzoate are obtained.

1. custom(approx. 2 hours)
2. temperaturethe mixture is refluxed for a further hour
3. concentrationIt is subsequently concentrated
4. dissolutionredissolved in 300 ml of dichloromethane
5. additionis added dropwise
6. washwashed in succession with sodium carbonate solution and sodium chloride solution
7. dry with materialthe organic phase is then dried over magnesium sulfate
8. customAfter removal of the solvent, 64.5 g (87% of theory) of crude 3-oxocyclohex-1-enyl 2-chloro-4-methyl-sulfonyl-3-(3a,4,5,6a-tetrahydrofuro[3,2-d]isoxazol-3-yl)benzoate
9. customare obtained