Sulfuric Acid → 5-chloro-1H-indole-2,3-dione

Participants

Reaction Conditions

Reaction Steps

To a hot solution of conc. H2SO4 (20 mL) at 60° C. was added portion wise N-(4-chloro-phenyl)-2-hydroxyimino-acetamide (5.5 g, 27.0 mmol). After the addition, the temperature was increased to 80° C. and maintained for one hour. After completion of the reaction, the reaction mixture was poured on to crushed ice and the resulting precipitated solid was separated, filtered, washed with water (2-3 times) and dried to obtain the title compound as brick red solid.

Provenance & Evidence