Synthsis Of Derivatives Of 5-ASA For The Treatment Of IBD

Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease, which have been popular among Europeans and Americans, are now getting increased in Asian countries such as Japan, Korea, and China since the end of the 1990's. The exact etiology of the IBD is not yet clearly understood. For many years, sulphasalazine (SASP) and 5-aminosalicylic acid(S-ASA) have been used in the treatment of IBD. Recently, 4-ASA has been reported as highly effective as 5-ASA in the maintenance treatment of IBD. But after oral ingestion uncoated 4-ASA is rapidly absorbed in the upper intestinal tract. So delivery of orally administered 4-ASA specifically to the colon is highly desirable. Results from in vitro experiments suggested that 5-ASA-Gly is a colon-specific prodrug of 5-ASA. As 4-ASA is an isomer of 5-ASA and they have the similar structure, glycine can be choosed as a colon-specific carrier. In this paper, we investigated the synthetic route in the conjugating reaction of glycine and 4-ASA, and five intermediates have been prepared. We characterized their structures. They are characterized by melting point, TLC, FT-IR, 'H-NMR and 13C-NMR spectra properties in details. Their structures are given out. By our studying, we have provided a suitable synthesis route for further exploring new compounds in the treatment of IBD.