Ammonia → 4-Chloro-5-(trifluoromethyl)pyrimidin-2-amine

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Reaction Steps

To stirred neat 2,4-dichloro-5-(trifluoromethyl)pyrimidine (F-1) (5.0 g, 23.04 mmol) under argon, ammonia in methanol (7N solution, 15 mL) is added dropwise and the resulting mixture is stirred at RT for 2 h. The reaction mixture is quenched with water and then extracted with ethyl acetate (200 mL×2). The combined organic layers are washed with brine, dried over Na2SO4 and filtered. The filtrate is concentrated in vacuo and the residue is purified by flash chromatography on silica gel eluting with 0-20% ethyl acetate/hexanes to afford the product, 4-chloro-5-(trifluoromethyl)pyrimidin-2-amine (F-2) (1.03 g, 22.6% yield). The other regio-isomer, 2-chloro-5-(trifluoromethyl)pyrimidin-4-amine (F-3), can also be isolated.

Provenance & Evidence