Sodium hydride → HCID 68669299, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1-butylpiperazine-2,3-dione (Intermediate D, 500 mg, 2.9 mmol) in 4 mL DMF, cooled to 0° C., was added sodium hydride (60% dispersion in mineral oil, 128 mg, 3.2 mmol). The reaction was stirred at rt for 30 min, recooled to 0° C. and a solution of methyl 2-bromo-4-phenylbutanoate (Intermediate C, 820 mg, 3.2 mmol) in 1 mL DMF was added dropwise. The mixture was stirred at rt for 1 h, quenched with brine and extracted with EtOAc. Drying, solvent evaporation and flash chromatography (silica gel, 35-90% EtOAc/hexanes) gave methyl 2-(4-butyl-2,3-dioxopiperazin-1-yl)-4-phenylbutanoate. 1H NMR (CDCl3) δ 7.29 (m, 2H), 7.18 (m, 3H), 5.27 (X of ABX, 1H, J=10.8 Hz, J=4.6 Hz), 3.72 (s, 3H), 3.63 (m, 1H), 3.54 (m, 1H), 3.47 (m, 2H), 3.38 (m, 1H), 3.28 (m, 1H), 2.67 (m, 2H), 2.36 (m, 1H), 2.03 (m, 2H), 1.57 (m, 2H), 1.35 (m, 2H), 0.95 (t, 3H, J=7.3 Hz).

Provenance & Evidence