Synthesis of THIQ Derivatives as Potential Boron Neutron Capture Therapy Agents: N-Functionalized o-Carboranylmethyl Benzopiperidines

A method for synthesizing o-carborane substituted tetrahydroisoquinolines containing a polar functional group such as sulfonic or phosphoric acid on the nitrogen atom of the piperidine ring, starting from N-(2-arylethyl)sulfamic acid or 2arylethylamidophosphate, is described. In vitro studies showed that the desired compounds 7a and 10b accumulate to high levels in B-16 melanoma cells despite low cytotoxicity.