反应详情

To a solution of 4-amino-3-(2-bromophenoxy)-benzonitrile, 2a (0.8 g; 2.77 mmol) and 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (1.1 g; 5.52 mmol) in dichloroethane (80 mL) was added sodium triacetoxyborohydride (1.17 g; 5.52 mmol) and acetic acid (0.16 mL; 2.8 mmol). The mixture was stirred for 2 h at rt. An additional 4 equiv of sodium triacetoxyborohydride was added, and the mixture was heated to 90° C. for 5 h. The mixture was allowed to cool to rt, diluted with ethyl acetate (15 mL) and treated with H2O (15 mL). The organic layer was separated, dried over MgSO4, filtered, and evaporated. The residue was purified via column chromatography (eluent gradient: 0 to 30% ethyl acetate in heptane) to yield 0.6 g (46%) of 4-[2-(2-bromophenoxy)-4-cyanophenylamino]-piperidine-1-carboxylic acid tert-butyl ester, 3a. MS m/z (MH+) 493.7.

1. temperaturethe mixture was heated to 90° C. for 5 h
2. temperatureto cool to rt
3. customThe organic layer was separated
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified via column chromatography (eluent gradient: 0 to 30% ethyl acetate in heptane)