Commercially available mycophelonic acid (I) is converted to its chloride (II) by means of thionyl chloride in dichloromethane/DMF and then esterified with 2-(4-morpholinyl)ethanol (III) in dichloromethane.
The esterification of mycophenolic acid (I) with 2-(4-morpholinyl)ethanol (II) in refluxing dibutyl ether or refluxing dipentyl ether with azeotropic distillation of water gives the target mycophenolic ester.