反应详情

温度

-20 °C

To a solution of Boc-Abu-OH (2.979 g, 14.66 mmol) in acetonitrile (50 mL) and 4-methylmorpholine (1.78 mL, 16.2 mmol) cooled to −20° C. was added isobutyl chloroformate (1.92 mL, 14.8 mmol) dropwise. The mixture was stirred for an additional 90 minutes at −20° C. and then 4-bromo-1,2-benzenediamine (2.86 g, 15.3 mmol) was added. The reaction mixture was allowed to warm to room temperature and stirred for 5 hours. The solvent was evaporated, redissolved in ethyl acetate, washed with water, saturated aqueous solution of sodium hydrogen carbonate, and brine. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The resulting residue was dissolved in acetic acid (5.0 mL, 88 mmol) and stirred at room temperature for 18 hours. The acetic acid was removed in vacuo and purified by silica gel column chromatography eluting with a 0-100% ethyl acetate/hexanes gradient. The residue was recrystallised from a mixture of ethyl acetate/hexanes to afford the title compound (2.65 g, 51%) as a white solid.

1. temperatureto warm to room temperature
2. stirringstirred for 5 hours
3. customThe solvent was evaporated
4. dissolutionredissolved in ethyl acetate
5. washwashed with water, saturated aqueous solution of sodium hydrogen carbonate, and brine
6. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. stirringstirred at room temperature for 18 hours
10. customThe acetic acid was removed in vacuo
11. custompurified by silica gel column chromatography
12. washeluting with a 0-100% ethyl acetate/hexanes gradient
13. customThe residue was recrystallised from a mixture of ethyl acetate/hexanes