反应详情

A solution of 4-(aminosulphonyl)phenylhydrazine chlorohydrate (0.82 g, 3.69 mmoles) and (E)-1,1,1-trifluoro-4-(4-methylphenyl)-3-butene-2-one (0.79 g, 3.69 mmoles) in 15 ml of acetic acid is refluxed for 3 hours under a nitrogen atmosphere. It is cooled, poured over water and extracted with AcOEt. The organic solution is washed with water, dried over anhydrous sodium sulphate and evaporated to dryness under vacuum. The crude product thus obtained is crystallised from EtOH-petrol ether to give 1-(4-aminosulphonylphenyl)-4,5-dihydro-5-(4-methylphenyl)-3-trifluoromethyl-1H-pyrazole (0.65 g, yield: 45%).

1. temperatureIt is cooled
2. extractionextracted with AcOEt
3. washThe organic solution is washed with water
4. dry with materialdried over anhydrous sodium sulphate
5. customevaporated to dryness under vacuum
6. customThe crude product thus obtained
7. customis crystallised from EtOH-petrol ether