Pyridine → 3-cyano-N-[2,6-dimethyl-4-(1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl)-phenyl]-5-nitro-benzamide

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Reaction Steps

To a suspension of 3-cyano-5-nitro-benzoic acid (Example I4) (7.2 g, 37.5 mmol) in dichloromethane (40 ml) was added oxalyl chloride (3.808 ml, 45 mmol) at ambient temperature, followed by N,N-dimethylformamide (“DMF”) (0.2 ml). The reaction mixture was stirred for 1 hour at ambient temperature and then heated to reflux for 3 hours. The reaction mixture was allowed to cool to ambient temperature and then concentrated. The to residue was suspended in tetrahydrofuran (50 ml). 2,6-dimethyl-4-(heptafluoro-prop-2-yl)-aniline (9.761 g, 33.7 mmol) (prepared according to EP 1,006,102) was dissolved in tetrahydrofuran (50 ml) and pyridine (6.035 ml, 75 mmol) was added. The mixture was cooled to 0° C. and the solution of 2-fluoro-5-nitro-benzoyl chloride was added. The reaction mixture was stirred at ambient temperature for 12 hours. Then aqueous sodium hydrogen carbonate (saturated) (100 ml) was added and the organic phase extracted twice with ethyl acetate (2×200 ml). The combined organic extracts were dried over sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: cyclohexane/ethyl acetate 6:1) to give 3-cyano-N-[2,6-dimethyl-4-(1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl)-phenyl]-5-nitro-benzamide (12 g, 77% yield). 1H-NMR (400 MHz, CDCl3): 8.99 (m, 1H), 8.72 (m, 1H), 8.6 (m, 1H), 7.80 (s, 1H), 7.4 (s, 2H), 2.33 (s, 6H) ppm.

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