2-Amino-3-bromopyridine → Benzyl 4-[2-[(3-bromopyridin-2-yl)amino]-2-oxoethyl}-3,6-dihydropyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

Trimethylaluminum (2.0 M, 2.05 mL, 4.10 mol) was added slowly to a 0° C. solution of benzyl 4-(2-methoxy-2-oxoethyl)-3,6-dihydropyridine-1(2H)-carboxylate (0.79 g, 2.73 mol) and 2-amino-3-bromopyridine (0.520 g, 3.00 mmol) in 1,2-dichloroethane (15 mL). After 30 min, the reaction was heated to 55° C. for 48 h. The reaction was quenched by the careful addition of saturated aqueous sodium bicarbonate and the mixture extracted with dichlormethane (4×). The combined organic layers were washed with 1N sodium potassium tartrate, brine, dried over MgSO4, filtered, and concentrated. The crude product was purified by silica gel chromatography, eluting with a gradient of 50 to 100% ethyl acetate:hexanes to give the title compound (2.44 g). MS: m/z=430.0 (M+1).

Provenance & Evidence