反应详情

In a flask with an inert atmosphere (E)-1,1,1-trifluoro-4-methyl-4-(4-methylphenyl)-3-butene-2-one (1.75 g, 8.2 mmoles), 4-(aminosulphonyl)phenylhydrazine chlorohydrate (2 g, 9 mmoles) and piperidine (0.85 g, 10 mmoles) are added, dissolved in 100 ml of ethanol, and heated under reflux for 5.5 hours. The mixture is cooled, the solvent eliminated with a rotovapor, water added to the residue and the solution extracted with AcOEt. The organic phase is washed with water, dried over anhydrous sodium sulphate and evaporated to dryness. The crude product is purified using column chromatography through silica gel under pressure, eluting with AcOEt-petrol ether (4:6) obtaining 1-(4-aminosulphonylphenyl)-4,5-dihydro-5-phenyl-5-methyl-3-trifluoromethyl-1H-pyrazole in the form of a white solid (1.46 g, yield: 47%) with a

1. temperatureheated
2. temperatureunder reflux for 5.5 hours
3. temperatureThe mixture is cooled
4. additionadded to the residue
5. extractionthe solution extracted with AcOEt
6. washThe organic phase is washed with water
7. dry with materialdried over anhydrous sodium sulphate
8. customevaporated to dryness
9. customThe crude product is purified
10. washeluting with AcOEt-petrol ether (4:6)