反应详情

To a solution of 3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)benzoic acid (200 mg, 6.90×10−4 mol) in chloroform (15 mL) were added oxalyl chloride (0.5 mL) and DMF in a catalytic amount. The reaction mixture was stirred at room temperature for 30 minutes, and the solvent was distilled off under reduced pressure. The residue was dissolved in anhydrous THF (20 mL), and 5-hydroxy-1-ethylpyrazole hydrochloride (134 mg, 9.01×10−4 mol), triethylamine (139 mg) and N,N-dimethylaminopyridine (170 mg) were added. The mixture was heated at refluxed temperature for 1 hour. The reaction mixture was allowed to cool to room temperature, and then ethyl acetate (200 mL) was added. The mixture was washed twice with a saturated brine, and the organic layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure. The residue was dissolved in anhydrous acetonitrile (10 mL), and triethylamine (139 mg) and acetone cyanohydrin in a catalytic amount were added, followed by stirring for 12 hours at room temperature. The solvent was distilled off under reduced pressure to obtain crude 5-hydroxy-1-ethylpyrazol-4-yl 3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl ketone.

1. distillationthe solvent was distilled off under reduced pressure
2. dissolutionThe residue was dissolved in anhydrous THF (20 mL)
3. temperatureThe mixture was heated
4. temperatureat refluxed temperature for 1 hour
5. temperatureto cool to room temperature
6. washThe mixture was washed twice with a saturated brine
7. dry with materialthe organic layer was dried over anhydrous sodium sulfate
8. distillationThe solvent was distilled off under reduced pressure
9. dissolutionThe residue was dissolved in anhydrous acetonitrile (10 mL)
10. additiontriethylamine (139 mg) and acetone cyanohydrin in a catalytic amount were added
11. stirringby stirring for 12 hours at room temperature
12. distillationThe solvent was distilled off under reduced pressure