反应详情

A cold (0° C.) solution of N-phenylsulphonyl-4-nitroaniline (7.39 g, 30 mmol) in DMF (65 mL) was treated with sodium hydride (0.76 g, 32 mmol) portionwise over a period of 1.5 h. A solution of ethyl bromoacetate (4 mL) in DMF (10 mL) was added, and the resultant mixture stirred at RT overnight. The product mixture was concentrated under vacuum, and the residue dissolved in ethyl acetate. The organic extract was washed with brine, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluting with 0.5% methanol in chloroform. Collection and concentration of appropriate fractions provided N-4-nitrophenyl-N-phenylsulfonylglycine ethyl ester (4-8a) as a clear gum. ##STR41## Step 2: N-{4-[4-(4-tert-Butyloxycarbonylpiperazin-1-yl)phenylcarbonyl-amino]phenyl}-N-phenylsulfonylglycine ethyl ester (4-10a)

1. concentrationThe product mixture was concentrated under vacuum
2. dissolutionthe residue dissolved in ethyl acetate
3. extractionThe organic extract
4. washwas washed with brine
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated under vacuum
8. customCollection and concentration of appropriate fractions