Triethylamine → 2-[2-(3-chloro-pyridin-2-yl)-5-trifluoromethyl-2H-pyrazol-3-yl]-pyrido[2,3-d][1,3]oxazin-4-one

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Reaction Steps

5-Trifluoromethyl-2-(3-chloro-pyridin-2-yl)-2H-pyrazole-3-carboxylic acid chloride (example 2, step 3) (800 mg) was added to a mixture of 2-aminonicotinic acid (356 mg) in acetonitrile (20 mL). The mixture was stirred for 10 minutes at room temperature and triethylamine (360 μL) was added and stirred for 15 minutes, before a second portion of triethylamine (720 μL) was added. After the mixture was stirred for further 15 minutes at room temperature, methanesulfonyl chloride (220 μL) was added. After stirring for 1.5 hours at room temperature, the reaction was quenched with water and extracted 2× with ethyl acetate, washed with brine, dried over MgSO4 and concentrated in vacuum. The residue was purified by column chromatography (silica 60, chloroform/ethyl acetate=1:1, Rf=0.40) to afford 660 mg of the title compound of the formula

Provenance & Evidence