METHOD OF SYNTHESIS OF ANTHRANILIC ACID Russian patent published in 2002 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to the technology of production of 2-aminobenzoic (anthranilic) acid that is used as an intermediate substance in production of different dyes, medicinal and perfume substances. Process is performed by mixing sodium phthalimide or sodium phthalaminate solution with sodium hypochlorite alkaline solution in the mole ratio sodium phthalimide or sodium phthalaminate : sodium hypochloride : sodium hydroxide in the range = 1 : (1.005-1.06) : (2.0-2.05) at temperature from 15 to 15 C followed by neutralization of sodium hypochlorite excess with reducing agent at 15-35 C and keeping the reaction mixture at 40-85 C. The solution with mass part of sodium phthalimide in the range 23-28.7% is used as sodium phthalimide solution. The solution with mass part of sodium phthalaminate in the range 25-35% is used as sodium phthalaminate solution. The proposed method ensures to increase the yield of the end product an average by 4.6-8.3% and decrease the consumption norm of sodium hypochlorite by 0.5-29.3%. EFFECT: improved method of synthesis. 7 cl, 1 tbl