Abstract: In order to obtain the high anti-inflammatory, anti-ulcer and anti-viral drugs, using glycyrrhetinic acid, 11-deoxylglycyrrhetinic acid and 3-Ar-5-isoxazolemethylamine derivatives as the starting material, a series of novel isoxazole contained glycyrrhetinic acid derivatives were firstly synthesized and their chemical structures were confirmed by the methods of IR, ¹H NMR, ¹³C NMR and MS. At the same time, the optimum conditions for the amidation of glycyrrhetinic acid were confirmed by L₉(3⁴) orthogonal experiments, that is to say: with acetonitrile as the solvent, DCC/NMM as the catalytic reagent, the orders of the adding materials were as followings: adding 0.5 mmol GTA and 0.55 mmol DCC in 8 mL acetonitrile first, stirring in cold bath for 30 min and then adding 0.55 mmol 3-Ar-5-isoxazolemethylamine and 0.55 mmol NMM in 6 mL acetonitrile, and adding these mixtures to the reaction system by syringe; reaction time was 8 h. The success of this synthetic route indicates that the optimum conditions are higly reliable. Thus a facile and effective method is provide for synthesizing the isoxazole contained glycyrrhetinic acid derivatives.

Key words: Glycyrrhetinic acid, Isoxazole, Orthogonal experiment, Synthesis