反应详情

To a stirred mixture of 3-methoxy-2-methyl-4-(methylsulfonyl)benzoic acid (340 mg, 1.39 mmol) and 5-hydroxy-1-methylpyrazole hydrochloride (230 mg) in anhydrous methylene chloride (10 mL) were added DCC (dicyclohexylcarbodiimide) (315 mg) and triethylamine (260 mg) at room temperature, followed by stirring for 2 hours. The reaction mixture was subjected to filtration through Celite, the filtrate was concentrated, and the obtained residue was dissolved in 10 mL of anhydrous acetonitrile. Triethylamine (260 mg) and acetone cyanohydrin in a catalytic amount were added thereto, and the reaction solution was stirred overnight at room temperature. 150 mL of ethyl acetate was added to the reaction mixture, and the solution was washed once with a 1N hydrochloric acid aqueous solution and washed once with a saturated brine. The organic layer was dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate:methanol=9:1) to obtain 5-hydroxy-1-methylpyrazol-4-yl 3-methoxy-2-methyl-4-(methylsulfonyl)phenyl ketone (115 mg).

1. filtrationThe reaction mixture was subjected to filtration through Celite
2. concentrationthe filtrate was concentrated
3. dissolutionthe obtained residue was dissolved in 10 mL of anhydrous acetonitrile
4. additionTriethylamine (260 mg) and acetone cyanohydrin in a catalytic amount were added
5. stirringthe reaction solution was stirred overnight at room temperature
6. addition150 mL of ethyl acetate was added to the reaction mixture
7. washthe solution was washed once with a 1N hydrochloric acid aqueous solution
8. washwashed once with a saturated brine
9. dry with materialThe organic layer was dried over anhydrous sodium sulfate
10. distillationthe solvent was distilled off under reduced pressure
11. customThe obtained residue was purified by silica gel column chromatography (ethyl acetate:methanol=9:1)