Ethyl chloroformate → Ethyl 3,5-dibromoisonicotinate

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of LDA (64 mL, 128 mmol, 2 M solution) in anhydrous THF (100 mL) was added a solution of 3,5-dibromopyridine (28 g, 118 mmol) in anhydrous THF (100 mL). The reaction mixture was stirred at −78° C. for 45 minutes. Then, a solution of ethyl chloroformate (100 mL, 105 mmol) was added slowly over 15 minutes. After stirring for 15 minutes, the reaction mixture was quenched with a saturated solution of NaHCO3 (250 mL). The mixture was extracted into ethyl acetate (3×150 mL). The combined organic extracts were extracted with brine (2×400 mL), dried over MgSO4, filtered, evaporated, and dried in vacuo. The crude product was purified by flash chromatography (0-20% ethyl acetate/hexane), affording ethyl 3,5-dibromopyridine-4-carboxylate (33 g, 91% yield).

Provenance & Evidence