Réaction #2028885

Équation de réaction

4-Sulfonamidophenylhydrazine hydrochloride

diketone

6-methyl-2-(trifluoroacetyl)tetralone

→

pyrazole

Rendement 64.0%

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

Rendement 64.0%

Solvants

ethanol

Conditions de réaction

Traitement

1. 1
   TempératureThe reaction was heated
2. 2
   Températureto reflux
3. 3
   TempératureThe reaction mixture was cooled
4. 4
   Filtrationfiltered
5. 5
   ConcentrationThe filtrate was concentrated in vacuo
6. 6
   workup.DISSOLUTIONdissolved in ethyl acetate
7. 7
   Lavagewashed with water and with brine
8. 8
   Séchagedried over MgSO4

Mode opératoire

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.

Source