反应详情

1.12 g (0.01 mol) of 1-ethyl-5-hydroxypyrazole was dissolved in 30 ml of t-amyl alcohol, and 2.72 g (0.01 mol) of 4-methanesulfonyl-3-methoxycarbonyl-2-methylbenzoic acid, 2.27 g (0.011 mol) of N,N'-dicyclohexylcarbodiimide and 0.76 g (0.0055 mol) of anhydrous potassium carbonate were sequentially added thereto. The mixture was reacted at 80° C. for 6 hours under stirring. After completion of the reaction, t-amyl alcohol was distilled off under reduced pressure, and then water was added to the residue to dissolve the soluble component. The mixture was subjected to filtration to separate out the insolubles. The aqueous solution thus obtained was washed twice with chloroform, and then concentrated hydrochloric acid was added to adjust pH<1. The precipitated oil component was extracted with chloroform. The chloroform layer was washed sequentially with water and a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate Then, the solvent was distilled off under reduced pressure, and the residue thus obtained was recrystallized from water/ethanol to obtain 2.26 g of the desired product. (Yield: 62%, melting point: 150°-152° C.)

1. customThe mixture was reacted at 80° C. for 6 hours
2. distillationwas distilled off under reduced pressure
3. additionwater was added to the residue
4. dissolutionto dissolve the soluble component
5. filtrationThe mixture was subjected to filtration
6. customto separate out the insolubles
7. customThe aqueous solution thus obtained
8. washwas washed twice with chloroform
9. additionconcentrated hydrochloric acid was added
10. extractionThe precipitated oil component was extracted with chloroform
11. washThe chloroform layer was washed sequentially with water
12. dry with materiala saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate
13. distillationthe solvent was distilled off under reduced pressure
14. customthe residue thus obtained
15. customwas recrystallized from water/ethanol