Sulfuric Acid → 5-bromo-7-methoxy-2,3-dihydro-1H-indole-2,3-dione

Participants

Reaction Conditions

Reaction Steps

To concentrated H2SO4 (30 ml) at 65° C. was added N-(4-bromo-2-methoxyphenyl)-2-(hydroxyimino)acetamide (5.55 g, 20 mmol) portionwise. The mixture was heated at 90° C. for 1.5 h. The mixture was cooled to room temperature, poured onto ice, and stirred for 10 min. The solid was collected by filtration, washed with water, and air dried to afford 5-Bromo-7-methoxyindoline-2,3-dione (3.6 g, crude, 70% yield). This material was used without further purification. 1H NMR (400 MHz, DMSO-d6): δH 7.93 (s, 1H), 7.38 (s, 1H), 3.94 (s, 3H). MS (ESI) m/e [M+1]+ 256, 258.

Provenance & Evidence