background and overview[1]
6-hydroxyanthranilic acid is a carboxylic acid derivative and can be used as a pharmaceutical synthesis intermediate. if 6-hydroxyanthranilic acid is inhaled, move the patient to fresh air; if skin contact occurs, remove contaminated clothing, rinse skin thoroughly with soap and water, seek medical attention if you feel unwell; if contact with eyes , you should separate your eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse your mouth immediately, do not induce vomiting, and seek medical attention immediately.
preparation[1]
to a solution of 2-amino-6-methoxybenzoic acid (1 equiv) in anhydrous ch2cl2 at 78°c (dry ice/acetone bath), add boron tribromide (1m in ch2cl2, dropwise add 3 equivalents). the reaction mixture was stirred at room temperature under nitrogen atmosphere for 18 hours. then etoh and meoh were added, and the solvent was evaporated to obtain 6-hydroxyanthranilic acid as a brown solid solvent, yield: 75%.
apply[1]
6-hydroxyanthranilic acid can be used as a pharmaceutical synthesis intermediate. if the following reaction occurs:
1) use 6-hydroxyanthranilic acid and intermediate b as reaction raw materials, add a solvent, evaporate the solvent, and suspend the remaining solid in methanol. after filtration, the precipitate was washed with meoh to provide the title compound (80%). the beige solid was used in the next reaction without further purification; beige solid, yield: 50%.
2) combine the compound 2-([1,10-biphenyl]-4-yl)-5-hydroxy-4h-benzo[d][1,3]oxazin-4-one obtained in step 1) dissolve in thf and hydrolyze with aqueous solution containing 1mlioh at room temperature (18 hours). the mixture was acidified by adding 1 m hcl, filtered, and the precipitate was washed continuously and extracted with 1 m hcl and meoh to obtain the title compound. brown solid, yield: 61%.
main reference materials
[1] benzamidobenzoic acids as potent pqsd inhibitors for the treatment of pseudomonas aeruginosa infections