Compounds of the general formula ##STR1##

wherein R is selected from the group consisting essentially of hydrogen, methyl, ethyl, phenyl, a carboxyl, or naphthyl substituted or a carbonyl substituted, alkyl of from 3 to 20 carbon atoms, a mono, bi or tri cyclic aryl or substituted aryl for the inhibition of phosphatase enzymes, including metallophosphatases; and, novel methods for synthesizing such compounds. The methods of use include the administration of an effective amount of the compound to provide effective phosphatase inhibition and therapeutic use to treat or prevent certain diseases, which utilize specific phosphatase enzymes.