Reacción #2028885

Ecuación de reacción

4-Sulfonamidophenylhydrazine hydrochloride

diketone

6-methyl-2-(trifluoroacetyl)tetralone

→

pyrazole

Rendimiento 64.0%

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

Rendimiento 64.0%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction was heated
2. 2
   Temperaturato reflux
3. 3
   TemperaturaThe reaction mixture was cooled
4. 4
   Filtraciónfiltered
5. 5
   ConcentraciónThe filtrate was concentrated in vacuo
6. 6
   workup.DISSOLUTIONdissolved in ethyl acetate
7. 7
   Lavadowashed with water and with brine
8. 8
   Secadodried over MgSO4

Procedimiento

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.

Fuente