Water → N-Benzyl-5-methoxyisatin

Participants

Reaction Steps

A stirred solution of 5-methoxyisatin (5.0 g, 28 mmol) in dry DMF (40 mL) was cooled in an ice bath before addition of sodium hydride (60 wt % in mineral oil, 1.7 g, 42 mmol) slowly, the dark red solution turning quickly black. After stirring for 20 min, BnBr (3.7 mL, 31 mmol) was added to the reaction mixture by syringe and the resulting mixture was stirred for 1 h. Water (150 mL) was added with stirring, and the resulting dark red precipitate collected by filtration and washed with water to give 1-benzyl-5-methoxyindoline-2,3-dione as a dark red solid (6.1 g, 81%). 1H NMR (400 MHz, CDCl3) δ 7.39-7.31 (m, 5H), 7.17 (s, 1H), 7.03 (d, J=8.1 Hz, 1H), 6.68 (d, J=8.6 Hz, 1H), 4.92 (s, 2H), 3.79 (s, 3H). MS ESI 268.1 [M+H]+, calcd for [C16H13NO3+H]+ 268.09.

Provenance & Evidence