反应详情

To a solution of N′-hydroxy-4-(trifluoromethoxy)benzimidamide (1.3 g, 5.1 mmol) and 5-methyl-1H-1,2,4-triazole-3-carboxylic acid (650 mg, 5.1 mmol) in DMF (15 mL), EDC.HCl (980 mg, 5.1 mmol) and HOBT (690 mg, 5.1 mmol) were added at RT. The mixture was stirred at RT for 1 h, and then heated to 140° C. for 3 h. The resulting mixture was cooled, diluted with H2O (20 mL) and extracted with EtOAc (4×40 mL). The combined organic layers were washed with H2O (10 mL) and brine (10 mL), dried over Na2SO4, filtered and concentrated under reduced pressure, and the residue was purified by Combiflash reverse phase chromatography (50%˜60% MeCN/H2O containing 0.01% trifluoroacetic acid) to give 5-(5-methyl-1H-1,2,4-triazol-3-yl)-3-(4-(trifluoromethoxy)phenyl)-1,2,4-oxadiazole as a white solid (590 mg, 37%). MS (ES+) C12H8F3N5O2 requires: 311. found: 312[M+H]+.

1. temperatureheated to 140° C. for 3 h
2. temperatureThe resulting mixture was cooled
3. extractionextracted with EtOAc (4×40 mL)
4. washThe combined organic layers were washed with H2O (10 mL) and brine (10 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customthe residue was purified by Combiflash reverse phase chromatography (50%˜60% MeCN/H2O containing 0.01% trifluoroacetic acid)