Anthranilic acids from isatin: an efficient, versatile and environmentally friendly method

This paper describes the preparation of a series of 16 anthranilic acids in yields ranging from 51 to 97%, by treating the isatins with NaOH and H₂O₂. Independently of the nature of the substituent on the aromatic ring, the reactions were complete in 15 min at room temperature, whereas those of isatins containing a substituent on the nitrogen atom required longer reaction time for completion (45 min) under the same reaction conditions.

isatin; anthranilic acid; 2-aminobenzoic acid; isatin oxidation