反应详情

0.2 g of tetrabutylammonium fluoride and 5.6 g of potassium hydroxide powder are added to a solution of 6.9 g of 4-hydroxy-pyrazolidine-N,N'-dicarboxylic acid di-tert-butyl ester in 60 ml of tetrahydrofuran. At a maximum of 45° C., 8.0 g of chlorodifluoromethane are introduced. The reaction solution is then filtered, concentrated and purified by means of column chromatography to yield 2.7 g of the desired product, 4-difluoromethoxy-pyrazolidine-N,N'-dicarboxylic acid di-tert-butyl ester, in the form of a yellow oil.

1. filtrationThe reaction solution is then filtered
2. concentrationconcentrated
3. custompurified by means of column chromatography