反应详情

To a 0° C. suspension of 4-(4-bromophenoxy)benzene sulfonyl chloride (1.10 g, 3.16 mmol) in 20 mL of dichloromethane was added a solution of diisoproylethylamine (1.10 mL, 6.3 mmol) and D-valine tert-butyl ester (660 mg, 3.8 mol) in 11 mL of dichloromethane. The ice bath was removed, and the reaction was stirred for 3 h, diluted with 30 mL dichloromethane, and 30 ml of 1 M HCl was added. The layers were separated, and the aqueous layer was washed with 30 mL of dichloromethane. The combined dichloromethane fractions were washed with brine, dried over MgSO4, and concentrated. The residue was chromatographed on silica, eluting with 25% ethyl acetate in hexane, to give 980 mg (64%) of N-[4-(4-bromophenoxy)benzenesulfonyl]-D-valine t-butyl ester as a white foam.

1. customThe ice bath was removed
2. additiondiluted with 30 mL dichloromethane, and 30 ml of 1 M HCl
3. additionwas added
4. customThe layers were separated
5. washthe aqueous layer was washed with 30 mL of dichloromethane
6. washThe combined dichloromethane fractions were washed with brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated
9. customThe residue was chromatographed on silica
10. washeluting with 25% ethyl acetate in hexane