REACTION OF PYRYLIUM-SALTS WITH AMINO-ACID DERIVATIVES .4. SYNTHESIS AND BIOLOGICAL-ACTIVITY AS ENZYME-INHIBITORS OF 4-AMINO-2-HYDROXYBENZOIC ACID-DERIVATIVES

Reaction of 4-amino-2-hydroxybenzoic acid with 2,4,6-trisubstituted py rylium salts, afforded the corresponding pyridinium derivatives. By es terification of such compounds with methanol, the methyl esters were o btained, whereas by treatment with acetic anhydride the phenolic OH gr oup is acetylated. Treatment with diazomethane afforded the correspond ing ester-ethers. The new compounds-characterized by elemental analysi s, IR- and H-1-NMR spectroscopy - were assayed as inhibitors of the en zyme carbonic anhydrase. Some compounds proved interesting biological activity.