1-Chloro-4-isocyanato-2-(trifluoromethyl) benzene → 1-(4-Chloro-3-trifluoromethyl-phenyl)-3-[3-(2-phenyl-4-pyridin-4-yl-2H-pyrazol-3-yl)-phenyl]-urea

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Reaction Steps

3-(1-Phenyl-4-pyridin-4-yl-1H-pyrazol-3-yl)-phenylamine (as regioisomeric mixture) was dissolved in dry dichloromethane (1 mL) under nitrogen atmosphere, 4-chloro-3-trifluoromethylphenylisocyanate (61 mg, 0.275 mmol, 1.4 eq) was added and the reaction mixture was stirred at room temperature for 3 hours. The solution was concentrated to dryness and purified by chromatography on silica gel (SP1, gradient n-hexane/ethyl acetate 1:1 to pure ethyl acetate). Two pools of fractions containing the two separated regioisomers were obtained, together with some mixed fractions (total yield 78%). 55 mg of 1-(4-Chloro-3-trifluoromethyl-phenyl)-3-[3-(2-phenyl-4-pyridin-4-yl-2H-pyrazol-3-yl)-phenyl]-urea were obtained as colourless oil.

Provenance & Evidence