Synthesis of PAMAM Dendrimers Loaded with Mycophenolic Acid to Be Studied as New Potential Immunosuppressants

Abstract

The terminalN-Boc protected diamino PAMAM7was condensed (EDC-DMAP) with two units of mycophenolic acid (MPA) giving theN-Boc protected dendron8in a good yield (76%). The ammonium trifluoroacetate9was prepared from8by acid treatment (TFA-THF-H2O) and was split into two equal parts. The first half was treated with di-2-pyridyl thionocarbonate (DPT) in the presence of Et3N to give the corresponding isothiocyanate10. This was reacted with the second half of9providing the symmetrical dendrimer11(68% yield), exposing four MPA units around the thioureido-PAMAM core.