Synthesis of a new adrenal cortex imaging agent 6β‐131 I‐iodomethyl‐19‐nor cholest ‐5(10)‐en‐3β‐ol (NP‐59)

A new adrenal cortex imaging agent. 6β-131 I-iodomethyl-19-norcholest-5(10)-en-3β-ol (NP-59)[I] was synthesized by the homallylic rearrangement of 19-iodocholesterol or directly from cholest-5-ene-3β, 19-diol-19-toluene-p-sulfonate via homoallylic rearrangement with the iodide ion as a nucleophile and subsequent exchange with Na131I. NP-59 appears to concentrate 5 times better than 19-iodocholesterol in the rat adrenal and is currently being evaluated as a possible diagnostic agent in man.