Hydrochloric Acid → 3-Chloro-2-(4-chloro-3-methoxyphenyl)-5-trifluoromethylpyridine

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Reaction Steps

38.8 g (0.180 mol) of 2,3-dichloro-5-trifluoromethylpyridine, 33.5 g (0.180 mol) of 4-chloro-3-methoxybenzeneboronic acid, 0.7 g (0.61 mmol) of tetrakis(triphenylphosphine)palladium(O) and 45.3 g (0.539 mol) of sodium bicarbonate in a mixture of 550 ml of dimethoxyethane and 550 ml of water were refluxed for four hours. The mixture was then acidified to pH 4-5 with dilute hydrochloric acid, the dimethoxyethane was removed by distillation, and the remaining aqueous phase was extracted with methylene chloride. The combined methylene chloride phases were washed with water, dried over sodium sulfate and evaporated. The residue was stirred with a little cold n-hexane, filtered off with suction and dried. Yield: 44.2 g (76%) of colorless crystals of melting point 72° C.

Provenance & Evidence