Patent ID: 7271253

Claim:
A process for the preparation of Balsalazide and its pharmaceutically acceptable salts wherein the reaction comprises: a. the intermediate N-(4-aminobenzoyl)-β-alanine is converted to N-(4-ammoniumbenzoyl)-β-alanine sulfonate salt using a sulfonic acid in water, b. the N-(4-ammoniumbenzoyl)-β-alanine sulfonate salt is treated with aqueous sodium nitrite solution at low temperature to generate N-(4-diazoniumbenzoyl)-β-alanine sulfonate salt, c. the aqueous solution obtained is quenched with aqueous disodium salicylate to furnish Balsalazide disodium solution, d. the solution is acidified to allow isolation of Balsalazide, and e. optionally converting the Balsalazide to a pharmaceutically acceptable salt (such as disodium salt).