Pyridine → 4-[(3-Chloro-1-oxopropyl)amino]-2-hydroxybenzoic acid

Participants

Reaction Steps

7.5 g of 4-Aminosalicyclic acid was dissolved in 300 ml of acetonitrile at about 60° C. 12 ml of 3-chloropropionyl chloride was added dropwise and followed by addition of 5 ml of pyridine, the resulting mixture was refluxed for three hours. The mixture, which became clear after approximately 20 minutes of refluxing, was cooled and evaporated to dryness under reduced pressure. A gummy oil was dissolved in isopropanol-water and refrigerated for several days. A small amount of solid thus produced was filtered off. The filtrate was evaporated to dryness and approximately 16.8 g of crude 4-(3-chloropropionamido) salicyclic acid was produced. A lens treated with this compound was found to be clear with excellent UV blockage up to about 320 nm.

Provenance & Evidence