تفاعل #363322

معادلة التفاعل

1,1,1-trifluoro-4-(2,4-difluorophenyl)-3-butene-2-one

4-(aminosulphonyl)phenylhydrazine

sodium ethoxide

→

1-(4-aminosulphonylphenyl)-5-(2,4-difluorophenyl)-4,5-dihydro-3-trifluoromethyl-1H-pyrazole

المردود 65.0%

المذيبات

ethanol

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe mixture was refluxed for 16 hours
2. 2
   درجة الحرارةThe mixture was cooled
3. 3
   أخرىevaporated to dryness, cold water
4. 4
   workup.ADDITIONadded
5. 5
   workup.ADDITIONby adding acetic acid
6. 6
   ترشيحthe precipitated solid filtered
7. 7
   workup.DISSOLUTIONThis solid was redissolved in ether
8. 8
   workup.ADDITIONtreated with active C
9. 9
   ترشيحfiltered
10. 10
    أخرىThe resulting residue was crystallised from ethyl ether-petrol ether (50:50)

الإجراء التجريبي

In a flask with an inert atmosphere sodium ethoxide (0.53 g, 7.72 mmoles) is dissolved in 45 ml of ethanol. 1,1,1-trifluoro-4-(2,4-difluorophenyl)-3-butene-2-one (prepared according to method E-1) (0.913 g, 3.86 mmoles) and 4-(aminosulphonyl)phenylhydrazine chlorohydrate (0.87 g, 3.87 mmoles) are added and the mixture was refluxed for 16 hours. The mixture was cooled, evaporated to dryness, cold water added, and the mixture acidified by adding acetic acid and the precipitated solid filtered. This solid was redissolved in ether, treated with active C, filtered and the solvent eliminated with a rotovapor. The resulting residue was crystallised from ethyl ether-petrol ether (50:50) to give 1-(4-aminosulphonylphenyl)-5-(2,4-difluorophenyl)-4,5-dihydro-3-trifluoromethyl-1H-pyrazole (1.02 g, yield: 65%) in the form of a solid m.p.=160-2° C.

المصدر