Citric Acid → 3-Trifluoromethyl-5-(4-trifluoromethyl-phenyl)-pyridin-2-ylamine

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Reaction Steps

A mixture of the above 5-bromo-3-trifluoromethyl-pyridin-2-ylamine (9.90 g, 41.1 mmol), commercially available 4-(trifluoromethyl)benzeneboronic acid CAS-No. [128796-39-4] (8.58 g, 45.2 mmol), 1N aqueous Na2CO3-solution (98.6 mL, 98.6 mmol) and Pd(PPh3)4 (475 mg, 1 mol %) in DME (205 mL) was refluxed under argon atmosphere for 1 h. Poured into 5% citric acid, extracted with EtOAc, washed the organic layers with sat. NaHCO3-sol. and brine, dried over Na2SO4. Removal of the solvent in vacuum left a grey solid (13.96 g) which was purified by silica gel flash chromatography with heptane/EtOAc 4:1 to 2:1 to give the title compound as a light yellow solid (10.90 g, 87%). MS (ISN) 305 [(M−H)−]; mp 168° C.

Provenance & Evidence