反应详情

A mixture of the acid (7-C) (138.9 mg, 0.439 mmol) and 2-(trifluoromethyl)benzoic hydrazide (7-D) (89.7 mg, 0.439 mmol) was first co-evaporated with toluene three times. Dichloromethane (7 mL) was added to the mixture as solvent. To the resulting suspension was added 2-chloro-1,3-dimethylimidazolinium chloride (743 mg, 4.39 mmol) followed by triethylamine (1.2 mL, 8.78 mmol). The mixture was allowed to stir at room temperature under nitrogen for 48 h to ensure the completion of the reaction. The reaction mixture was then diluted with dichloromethane, washed with water, 1N HCl, saturated sodium bicarbonate aqueous solution, and lastly brine. The organics were dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by column chromatography using hexane/ethyl acetate (3/1) as eluent to give 3-(4-fluorophenyl)-5-(4-{5-[2-(trifluoromethyl)phenyl]-1,3,4-oxadiazol-2-yl}bicyclo[2.2.2]oct-1-yl)-1,2,4-oxadiazole (7-E) as a white solid. 1H NMR (500 MHz, CDCl3) δ 2.25 (s, 12H), 7.21 (t, J=8.7 Hz, 2H), 7.74-7.76 (m, 2H), 7.91 (m, 1H), 8.11-8.15 (m, 3H) ppm. ESI-MS m/z (M+H) 485.2.

1. customthe completion of the reaction
2. washwashed with water, 1N HCl, saturated sodium bicarbonate aqueous solution, and lastly brine
3. dry with materialThe organics were dried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by column chromatography