SYNTHESIS AND CHARACTERIZATION OF A BORONATED METALLOPHTHALOCYANINE FOR BORON NEUTRON-CAPTURE THERAPY

Synthesis of the first fully characterized, water-soluble boronated ph thalocyanine is reported. Reaction of 4-nitrophthalonitrile with dimet hyl malonate in the presence of base yielded dimethyl (3,4-dicyanophen yl)malonate which was converted into dimethyl (3,4-dicyanophenyl)propa rgylmalonate by sequential treatment with potassium hydroxide and prop argyl bromide. Formation of the o-carborane cage was accomplished by r eaction of the alkyne with decaborane in acetonitrile at reflux. High- temperature solid state condensation of the resulting o-carboranylphth alonitrile with cobalt(II) chloride followed by ester deprotection and cation exchange provided the water-soluble closo-carbonylphthalocyani ne product. The product contains 40 boron atoms (27% boron by weight) and may be useful as a tumor-seeking boron delivery agent for boron ne utron capture therapy of cancer.