反应详情

A solution of 1-(5-methyl-1,3,4-oxadiazol-2-yl)piperidin-4-one (79.6 mg, 440 μmol) and 8-(3,4-difluorophenyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyridin-2-amine (110 mg, 440 mmol) in toluene (5 mL) and acetic acid (280 μL) was heated to reflux at a Dean-Stark trap. The reaction mixture was cooled to room temperature and ethanol (3 mL) was added followed by sodium borohydride (66.5 mg, 61.9 μL, 1.76 mmol). The reaction mixture was stirred at 50° C. for 3 hours. Further sodium borohydride (66.5 mg, 61.9 μL, 1.76 mmol) was added and stirred at 50° C. for 3 hours. Water was added to the reaction mixture and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over Na2SO4 and the solvent was evaporated. The residue was purified by flash chromatography (silica gel, 100 g, 0% to 15% MeOH in dichloromethane, 40 minutes). The title compound was obtained as a white solid (32.8 mg, 18%). MS ISP (m/e): 416.3 (69) [(M+H)+]. 1H NMR (CDCl3, 300 MHz): δ (ppm)=7.16-7.07 (m, 1H), 7.00-6.93 (m, 1H), 6.91-6.87 (m, 1H), 4.12-4.01 (m, 4H), 3.93-3.87 (m, 2H), 3.72-3.60 (m, 1H), 3.23-3.13 (m, 2H), 2.38 (s, 3H), 2.32-2.23 (m, 1H), 2.18-1.88 (m, 5H), 1.58-1.48 (m, 2H).

1. temperatureto reflux at a Dean-Stark trap
2. stirringstirred at 50° C. for 3 hours
3. extractionthe aqueous phase was extracted with ethyl acetate
4. dry with materialThe combined organic layers were dried over Na2SO4
5. customthe solvent was evaporated
6. customThe residue was purified by flash chromatography (silica gel, 100 g, 0% to 15% MeOH in dichloromethane, 40 minutes)