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-butylammonium hydrogensulfate and 4.2 mL of bromo-acetic acid tert-butyl ester were added and stirring was continued over night. The solution was concentrated and acidified by addition of 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) of trans-[4-(benzyloxycarbonyl-methyl-amino)-cyclohexyloxy]-acetic acid as white solid, MS: 320 (M−H)−.

1. stirringstirring
2. waitwas continued over night
3. concentrationThe solution was concentrated
4. additionacidified by addition of 400 mL of 37% HCl
5. extractionThe solution was extracted with EtOAc
6. washthe organic phase was washed with brine
7. dry with materialdried over Na2SO4
8. customThe solvent was removed