Diisopropylethylamine → 2-Chloro-N-[3-(methylsulfonyl)benzyl]-5-(trifluoromethyl)pyrimidin-4-amine

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Reaction Steps

Diisopropylethylamine (31.5 mL, 180 mmol) was added to a suspension of 2,4-dichloro-5-trifluoromethylpyrimidine (XL, 15.0 g, 69.4 mmol) and 1-[3-(methylsulfonyl)phenyl]methanamine hydrochloride (13.3 g, 60 mmol) in THF (300 mL) at 0° C., and the resulting mixture stirred at room temperature overnight. The mixture was then evaporated to dryness, the residue taken up in methylene chloride (100 mL) and the resulting solution washed with water (100 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude residue obtained was taken up in hot methylene chloride (35 mL) then left to stir overnight at room temperature. The separated solid was isolated by filtration (9.4 g) and determined to be a pure sample of the more polar component of the product mixture (4-chloro-N-[3-(methylsulfonyl)benzyl]-5-(trifluoromethyl)pyrimidin-2-amine XLIVb). The mother liquors were adsorbed onto silica gel and chromatographed over silica gel eluting with hexane:ethyl acetate 50:50 to afford 8.5 g of pure non-polar material (2-chloro-N-[3-(methylsulfonyl)benzyl]-5-(trifluoromethyl)pyrimidin-4-amine XLIVa) and a further 0.7 g of the polar component.

Provenance & Evidence