Electric Literature of 21544-81-0, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 21544-81-0 as follows.
Hydrogen peroxide (30 % solution in water, 30 ml) was added dropwise to a stirred solution of 4,6-dimethoxy-2,3-dioxoindoline (27 g) in a concentrated aqueous sodium hydroxide solution (33 %, 220 ml). The resultant mixture was stirred at ambient temperature for 10 minutes. Ice was added and the basicity of the mixture was reduced to pH9 by the addition of concentrated aqueous hydrochloric acid and the mixture was then acidified to pH3.5 by the addition of glacial acetic acid. The resultant precipitate was isolated, washed with water and dried overnight under vacuum to give 2-amino-4,6-dimethoxybenzoic acid (15.9 g); NMR Spectrum : (DMSOd6) 3.7 (s, 3H), 3.78 (s, 3H), 5.79 (s, 1H), 5.92 (s, 1H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 4,6-Dimethoxyindoline-2,3-dione, its application will become more common.
Reference:
Patent; AstraZeneca AB; EP1292594; (2004); B1;,
Indoline – Wikipedia,
Indoline | C8H9N – PubChem