Synthesis of phenol-class azo derivatives of 4-aminosalicylic acid

To explore the better prodrug of 4-aminosalicylic acid (4-ASA) with higher activity and less side effects against the inflammatory bowel disease. 4-ASA, after a succession of synthesis process, was conjugated with various carrier molecules to get seven azo derivatives of 4-ASA. All compounds were characterized by FT-IR, 1H NMR, 13C NMR spectras in detail. New derivatives of 4-ASA were definituded.