反应详情

To a suspension of (6-trifluoromethyl-pyridin-3-yl)-acetic acid (257 mg, 1.25 mmol), 3,4-dimethylaniline (167 mg, 1.38 mmol) and 1-hydroxybenzotriazole in dichloromethane (2 mL) was added under a nitrogen atmosphere 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (264 mg, 1.37 mmol) and N,N-diisopropyl ethyl amine (322 μl, 1.88 mmol). After stirring for 3 h at ambient temperature it was concentrated and a solution of borane-tetrahydrofuran complex (1 M in THF, 5 mL, 5 mmol) was added and the reaction mixture was stirred for 18 h at 60° C. Further solution of borane-tetrahydrofuran complex (1 M in THF, 5 mL, 5 mmol) was added and the reaction mixture was stirred for 4 h at 80° C. An aqueous solution of hydrochloric acid (1 M, 2 mL) was carefully added and stirring was continued for 15 min. at reflux. After cooling it was diluted with ethyl acetate (15 mL) and washed with aqueous Na2CO3 (saturated, 15 mL). The aqueous layer was extracted with EtOAc (15 mL) and the combined organic layers dried over sodium sulfate. Concentration and purification by chromatography (SiO2, heptane:ethyl acetate=95:5 to 60:40) afforded the title compound (218 mg, 64%) as a light yellow oil. MS m/e: 295.2 [M+H]+.

1. concentrationwas concentrated
2. stirringthe reaction mixture was stirred for 18 h at 60° C
3. stirringthe reaction mixture was stirred for 4 h at 80° C
4. stirringstirring
5. waitwas continued for 15 min.
6. temperatureat reflux
7. temperatureAfter cooling it
8. washwashed with aqueous Na2CO3 (saturated, 15 mL)
9. extractionThe aqueous layer was extracted with EtOAc (15 mL)
10. dry with materialthe combined organic layers dried over sodium sulfate
11. concentrationConcentration and purification by chromatography (SiO2, heptane:ethyl acetate=95:5 to 60:40)