Methyl chloroformate → Methyl 5-bromo-3-cyanopyridin-2-ylcarbamate

関与物質

反応手順

Lithium bis(trimethylsilyl)amide in THF (1.0 N, 22 mL, 22 mmol) was added to a stirred solution of 2-amino-5-bromopyridine-3-carbonitrile (2.0 g, 10 mmol) in THF (30 mL) at −78° C. and the mixture was stirred at this temperature for 30 minutes. Methyl chloroformate (1.06 g, 11.1 mmol) was added and the mixture was warmed to room temperature and stirred for 2 hours. It was cooled in ice bath and quenched with saturated aqueous ammonium chloride (50 mL). The aqueous layer was extracted with ethyl acetate (3×50 mL) and the combined organic fractions were washed with brine (2×50 mL), dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified by LC (elution with 10% ethyl acetate in petroleum ether) to afford the carbamate (1.43 g, 63%). 1H NMR (400 MHz, CDCl3) δ 3.85 (s, 3H), 7.45 (br s, 1H), 8.05 (s, 1H), 8.65 (s, 1H). LCMS (M−1, 254.0).

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