Hydrochloric Acid → 1-(3-(trifluoromethyl)phenyl)-1H-pyrazole

Into a 500 ml., 2-neck flask, fitted with a condenser and a magnetic stirrer, is successively added 35.2 g. (0.2 M.) of m-trifluoromethylphenyl hydrazine, 15 ml. of water, 20 ml. of 100% ethanol, 16.5 ml. of concentrated hydrochloric acid (slowly) and 44.0 g. (0.2 M.) of 1,1,3,3-tetraethoxypropane. The reaction mixture is then heated slowly to between 80° C. and 90° C., and after maintaining the mixture at this temperature range for a period of between 2 and 3 hours, the reaction mixture is cooled, quenched on ice water, extracted with ethylacetate and washed several times with water. After drying the organic solution over sodium sulfate, the solvent is evaporated on a rotary evaporator to obtain a very dark liquid which is then distilled at 70° to 80° C. and a pressure of about 100 microns to yield a light yellow oil (Yield: 80%).