反应详情

温度

50 °C

To a stirred mixture of 1.8 g (0.0042 mole) of methyl 4-[2-chloro-4-fluoro-5-(4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4 -triazol-1-yl)phenoxy]-phenylcarboxylate and 1.3 g (0.0029 mole) of ethyl 4-[2-chloro-4-fluoro-5-(4-difluoromethyl-4,5-dihydro -3-methyl-5-oxo-1H-1,2,4-triazol-1-yl)phenoxy]phenylcarboxylate (prepared by the method of Step B using ethanol in place of methanol) in 20 mL of tetrahydrofuran was added a solution of 0.58 g (0.014) of sodium hydroxide in 30 mL of water. The reaction mixture was heated at 50° C. for 1.5 hour, then was stirred at room temperature for approximately 18 hours. The mixture was again heated at 50° C. for two hours and then was allowed to cool. The solvent was removed from the mixture by evaporation under reduced pressure leaving a residue. The residue was stirred in a 2N hydrochloric acid solution, and the resultant mixture was extracted successively with diethyl ether and ethyl acetate. The organic phases were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate concentrated under reduced pressure to give a solid residue. The residue was purified by column chromatography on silica gel, eluting with methylene chloride:methanol (95:5) to give 2.5 g of 4-[2-chloro-4-fluoro-5-(4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo 1H-1,2,4-triazol-1-yl)phenoxy]phenylcarboxylic acid as a solid, m.p. 184°-185° C.

1. customprepared by the method of Step B
2. temperatureThe mixture was again heated at 50° C. for two hours
3. temperatureto cool
4. customThe solvent was removed from the mixture by evaporation under reduced pressure
5. customleaving a residue
6. extractionthe resultant mixture was extracted successively with diethyl ether and ethyl acetate
7. dry with materialdried over anhydrous magnesium sulfate
8. filtrationfiltered
9. concentrationthe filtrate concentrated under reduced pressure
10. customto give a solid residue
11. customThe residue was purified by column chromatography on silica gel
12. washeluting with methylene chloride:methanol (95:5)