反应详情

To a suspension of 15.0 g (57 mmol) of trans-(4-hydroxy-cyclohexyl)-methyl-carbamic acid benzyl ester in 230 mL of toluene were added 16.8 mL (114 mmol, 2 eq) of bromo-acetic acid tert-butyl ester and 1.93 g (5.7 mmol, 0.1 eq) of tetra-n-butylammonium hydrogensulfate and 400 mL of 50% aqueous NaOH. The mixture was stirred at RT for 4 h, additional 1.93 g (5.7 mmol, 0.1 eq) of tetra-n-butyl-ammoniumhydrogensulfate and 4.2 mL of bromo-acetic acid tert-butyl ester were added, and stirring was continued over night. The solution was concentated and acidified by adding 400 mL of 37% HCl. The solution was extracted with EtOAc, the organic phase was washed with brine and dried over Na2SO4. The solvent was removed to yield 18.2 g (quantitative) trans-[4-(benzyloxycarbonyl-methyl-amino)-cyclohexyloxy]-acetic acid as white solid, MS: 320 (M−H)−.

1. stirringstirring
2. waitwas continued over night
3. extractionThe solution was extracted with EtOAc
4. washthe organic phase was washed with brine
5. dry with materialdried over Na2SO4
6. customThe solvent was removed