A Study on the Synthesis of NSAID Licofelone

Objective: To study the synthetic route of NSAID licofelone suitable for industrial production.Methods: The key intermediate substituted pyrrolizinone was obtained with 2,2-dimethyl-1,3-propanediol as the starting material via condensation,ring-opening,substitution,Grignard reaction and cyclization.The target product was synthesized sequentially by Friedel-Crafts reaction of the intermediate with oxalyl chloride and by Huang Ming-long reduction with hydrazine hydrate.Results:The target product was synthesized with a total yield of 13.3% and its structure was confirmed by IR,1HNMR and MS.Conclusion:The synthetic method is economical,convenient and suitable for industrial production.