Methyl formate → 3,5-Dibromo-2-methoxy-6-(trifluoromethyl)pyridine-4-carbaldehyde

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Reaction Conditions

Reaction Steps

To a flame-dried 100 mL round-bottomed flask, was added dry THF (15 mL). The solution was cooled to −78° C. and then N,N-diisopropylamine (0.46 mL, 3.28 mmol), 2.5M n-butyllithium in hexane (1.31 mL, 3.28 mmol), and a solution of the compound from Step B above (1.00 g, 2.99 mmol) in dry THF (10 mL) were added sequentially. The reaction mixture was stirred at −78° C. for 10 min before methyl formate (0.276 mL, 4.49 mmol) was slowly added. After the reaction was stirred for another 2 h, the mixture was warmed and stirred for 30 min at room temperature. Then the mixture was quenched by the addition of saturated aqueous ammonium chloride solution and extracted with ethyl acetate. The combined organic phases were washed sequentially with water and saturated brine, dried over sodium sulfate and concentrated. The residue was purified by flash chromatography (silica gel; 15% ethyl acetate/hexanes as eluant) to yield the title compound. 1H NMR (400 MHz, CDCl3) δ 10.10 (s, 1H), 4.11 (s, 3H).

Provenance & Evidence