Hydrochloric Acid → 3-Cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-(1-hydroxyethyl)-4-trifluoromethylthiopyrazole

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Reaction Conditions

Reaction Steps

Copper (I) iodide (6.1 g, 0.032 mol) was suspended in anhydrous diethyl ether and cooled to 0° C. Methyllithium (1.6 M in diethyl ether, 40 ml, 0.064 mol) was added via cannula and stirred 10 minutes. A solution of the product of Example 3 (10 g, 0.023 mol) in diethyl ether was added via cannula creating a bright yellow suspension. After 15 minutes, 10% aqueous hydrochloric acid (40 ml) was added while venting the reaction vessel. The remaining suspension was filtered through Celite® and washed with diethyl ether several times. The organic phase was washed with saturated sodium hydrogen carbonate solution, saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered and concentrated under reduced pressure. Trituration from pentane provided crystals that were purified by silica gel chromatography using ethyl acetate:hexanes. The title compound was isolated as a white solid (7.56 g), m.p. about 123° C.

Provenance & Evidence