5-Trifluoromethyl-1H-pyrrolo[2,3-b]pyridine

Synthesis

A solution of 3.4 g of 5-trifluoromethyl-3-[(trimethylsilyl)ethynyl]pyridin-2-amine and 2.96 g of potassium tert-butylate in 55 cm3 of N-methylpyrrolidinone is heated at 90 ℃. for three hours. The mixture is cooled to room temperature and then poured slowly into 250 cm3 of water saturated with ammonium chloride. The mixture is diluted with ethyl acetate and filtered, separating the phases into their isomers. The aqueous phase is extracted with ethyl acetate (2*100 cm3). The organic phases are combined, dried over magnesium sulphate and concentrated under a vacuum. The residue is slowly removed in water, and the resultant suspension is filtered. The solid is dried under vacuum to obtain 1.58 g of 5-trifluoromethyl-1H-pyrrolo[2,3-b]pyridine as a brown powder.