Ethyl bromoacetate → (+/-)-Ethyl (4-nitro-2-oxo-2,3-dihydro-1H-indol-3-yl)acetate

Participants

Reaction Steps

To a stirred solution of 4-nitro-1,3-dihydro-2H-indol-2-one (3.00 g, 16.8 mmol, described in Intermediate 17) in DMF (100 mL) at 0° C. was added sodium hydride (60% dispersion in mineral oil; 740 mg, 18.5 mmol) and the resulting mixture was stirred for 30 min. Ethyl bromoacetate (1.87 mL, 16.8 mmol) in DMF (10 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0° C. for 2 h, then quenched with H2O (200 mL). The mixture was extracted with EtOAc (5×200 mL) and the combined organic extracts were washed with brine (100 mL), then dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with a gradient of hexane:EtOAc—100:0 to 0:100, followed by crystallization from hexane:EtOAc to give the title compound. MS: m/z=265 (M+1).

Provenance & Evidence