反应详情

温度

65 °C

A stirred solution of 2-amino-4-nitrobenzoic acid (Aldrich; 18.2 g, 100 mmol) in dry THF (500 mL) at 20° C., is treated with a solution of borane-THF complex (BH3-THF; Fluka; 100 mL of 1.0 M), dropwise over 45 min to regulate the gas evolution. The mixture is then heated at 65° C. for 2 h. The stirred mixture is then cooled to 0° C., treated with water (20 mL) and warmed to RT. Upon the cessation of gas evolution, hydrochloric acid (20 mL of 12 M) is added and the mixture is then heated at 65° C. for 30 min. The cooled mixture is then concentrated to a volume of circa 150 mL by rotary evaporation under reduced pressure to give a suspension. The suspension is filtered and the precipitate is redissolved in ethyl acetate (500 mL) and washed with saturated aqueous sodium hydrogen carbonate (2×150 mL). The solution is dried (Na2SO4), filtered and the solvent is evaporated off under reduced pressure to yield the crude product which is purified by recrystallisation from ethyl acetate-hexane to give the title compound as a yellow crystalline solid, m.p. 126-128° C.

1. temperatureThe stirred mixture is then cooled to 0° C.
2. temperaturewarmed to RT
3. temperaturethe mixture is then heated at 65° C. for 30 min
4. concentrationThe cooled mixture is then concentrated to a volume of circa 150 mL by rotary evaporation under reduced pressure
5. customto give a suspension
6. filtrationThe suspension is filtered
7. dissolutionthe precipitate is redissolved in ethyl acetate (500 mL)
8. washwashed with saturated aqueous sodium hydrogen carbonate (2×150 mL)
9. dry with materialThe solution is dried (Na2SO4)
10. filtrationfiltered
11. customthe solvent is evaporated off under reduced pressure
12. customto yield the crude product which
13. customis purified by recrystallisation from ethyl acetate-hexane