Sulfuric Acid → 7-nitroisatin

Participants

Reaction Steps

2-Hydroxyimino-N-(2-nitro-phenyl)-acetamide (15 g, 72 mmol) was carefully added in small portions over a period of 30 min to a stirred solution of conc. sulphuric acid (45 mL) which was preheated to 90° C. The reaction mixture was stirred for another 2 h at the same temperature then cooled to room temperature, poured into crushed ice. The precipitated products were collected by filtrations, washed with water and dried in a vacuum oven to get 9 g (65%) of brick red colour powder.

Provenance & Evidence