反应详情

A solution of 1.19 g (2.6 mmol) trans-{4-[methyl-(4-trifluoromethyl-benzenesulfonyl)-amino]-cyclohexyloxy}-acetic acid tert-butyl ester in 20 ml of anhydrous THF was cooled to −78° and treated dropwise with a 1M solution of lithium bis-(trimethylsilyl)-amide in THF (6.2 ml, 2.5 eq). The mixture was allowed to reach RT within ca. 1 h and cooled again to −78°. A solution of 0.18 ml (2.9 mmol, 1.1 eq) of iodomethane in 2.5 ml of THF was added and the mixture allowed reach RT within ca. 1 h. After addition of ice, the mixture was extracted with EtOAc, dried over Na2SO4, and the solvent evaporated. Column chromatography on silica gel gave 600 mg (49%) of trans-2-{4-[methyl-(4-trifluoromethyl-benzenesulfonyl)-amino]-cyclohexyloxy}-propionic acid tert-butyl ester as a colorless solid, MS: 483 (M+NH4+).

1. temperaturecooled again to −78°
2. waitthe mixture allowed reach RT within ca. 1 h
3. additionAfter addition of ice
4. extractionthe mixture was extracted with EtOAc
5. dry with materialdried over Na2SO4
6. customthe solvent evaporated