Reaktion #2028885

Reaktionsgleichung

4-Sulfonamidophenylhydrazine hydrochloride

diketone

6-methyl-2-(trifluoroacetyl)tetralone

→

pyrazole

Ausbeute 64.0%

4-[4,5-dihydro-7-methyl-3-(trifluoromethyl)-1H-benz[g]indazol-1-yl]benzenesulfonamide

Ausbeute 64.0%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction was heated
2. 2
   Temperaturto reflux
3. 3
   TemperaturThe reaction mixture was cooled
4. 4
   Filtrationfiltered
5. 5
   EinengenThe filtrate was concentrated in vacuo
6. 6
   workup.DISSOLUTIONdissolved in ethyl acetate
7. 7
   Waschenwashed with water and with brine
8. 8
   Trocknendried over MgSO4

Vorschrift

4-Sulfonamidophenylhydrazine hydrochloride (1.80 g, 8.0 mmol) was added to a stirred solution of the diketone from Step 1 (1.86 g, 7.3 mmol) in ethanol (10 mL). The reaction was heated to reflux and stirred for 14.8 hours. The reaction mixture was cooled and filtered. The filtrate was concentrated in vacuo, dissolved in ethyl acetate, washed with water and with brine, dried over MgSO4 and reconcentrated in vacuo to give the pyrazole as a brown solid (1.90 g, 64%): mp 215°-218° C. 1H NMR (acetone-d6) 300 MHz 8.10 (d, 2H), 7.80 (d, 2H), 7.24 (s, 1H), 6.92 (d, 1H), 6.79 (br s, 2H), 6.88 (d,1H), 3.02 (m, 2H), 2.85 (m, 2H), 2.30 (s, 3H). 19F NMR (acetone-d6) 282 MHz −62.46 (s). High resolution mass spectrum Calc'd. for C19H17F3O2S: 408.0994. Found: 408.0989.

Quelle