N-bromobutanimide → 3-(4-Bromo-2-fluoro-phenylamino)-5-formylaminomethyl-pyrazine-2-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a −30° C. solution of 3-(2-fluoro-4-trimethylsilanyl-phenylamino)-5-formylaminomethyl-pyrazine-2-carboxylic acid methyl ester (1.84 g, 4.89 mmol) in dichloromethane (50 mL) under N2 was added NBS (0.96 g, 5.38 mmol, 1.1 eq.), and the reaction mixture was stirred at −30° C. for 3 h. More NBS (0.96 g, 5.38 mmol, 1.1 eq.) was added, and the reaction mixture was allowed to stand at 0° C. for 18 h. The reaction mixture was diluted with ethyl acetate (250 mL). The organic layer was washed with saturated aqueous solution of sodium bicarbonate, water and brine, dried (Na2SO4), filtered and concentrated in vacuo. The crude material was triturated with methanol to afford the desired product as a yellow solid (1.50 g, 80.1%). LCMS (method C): RT=2.51 min, [M+H]+=383/384.

Provenance & Evidence