反应详情

温度

65 °C

To a mixture of N-benzyloxycarbonyl-L-leucine (20 mmol, 5.3 g), 4-methoxy-1,2-phenylenediamine dihydrochloride (4.22 g, 20 mmol) and O-benzotriazole-N,N,N',N'-tetramethyl-uronium-tetrafluoroborate (TBTU) (6.58 g, 20.50 mmol) in 15 mL DMF cooled in an ice bath was added diisopropylethylamine (14 mL, 80 mmol). After stirring for 2 hours, ethyl acetate was added and the solution was washed with saturated NaHCO3 3 times and brine 3 times, dried (MgSO4), and concentrated. The crude product was dissolved in 30 mL acetic acid and the solution was heated at 65° C. for 2 hours. Acetic acid was removed by concentration under reduced pressure and the residue was purified on a silica gel column using methanol (3%)-methylene chloride as eluent to give 5.5 g (80%) product. m.p. 73°-77° C. ES-MS: calcd M+1 368.2; found 368.3.

1. temperaturecooled in an ice bath
2. washthe solution was washed with saturated NaHCO3 3 times and brine 3 times
3. dry with materialdried (MgSO4)
4. concentrationconcentrated
5. dissolutionThe crude product was dissolved in 30 mL acetic acid
6. customAcetic acid was removed by concentration under reduced pressure
7. customthe residue was purified on a silica gel column