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.