5-Fluoro-1-(4-methoxybenzyl)indoline-2,3-dione → 5-Fluoro-1-(4-methoxy-benzyl)-1,3-dihydro-indol-2-one

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Reaction Steps

A solution of 5-fluoro-1-(4-methoxy-benzyl)-1H-indole-2,3-dione (7.1 g, 24.9 mmol) in hydrazine hydrate (35 mL) and ethanol (15 mL) was refluxed overnight, diluted with water and extracted twice with ethyl acetate. The combined organics were dried over Na2SO4, filtered and concentrated. The residue was purified by silica gel chromatography using a gradient of 0-100% ethyl acetate in hexane to afford 6.1 g (90%) of 5-fluoro-1-(4-methoxy-benzyl)-1,3-dihydro-indol-2-one; 1H NMR (CDCl3, 400 MHz) δ 3.59 (s, 2H), 3.77 (s, 3H), 4.83 (s, 2H), 6.63 (dd, 1H, J1=4.2, J2=8.6), 6.82-6.91 (m, 3H), 6.96-7.01 (m, 1H), 7.19-7.23 (m, 1H), 7.27-7.31 (m, 1H); HPLC-MS calcd. for C16H14FNO2 (M+H+) 272.1, found 272.3.

Provenance & Evidence