Synthesis of H-3-labeled 2-hydroxy-N-[(1,3,3-trimethyl-[4,5,6-H-3]cyclohexyl)methyl]-5-azidobenzamide, a photoaffinity analog of an influenza fusion inhibitor

Synthesis of H-3-labeled 2-hydroxy-N-[(1,3,3-trimethyl-[4,5,6-H-3]cyclohexy l)methyl]-5-azidobenzamide, a photoaffinity analog of an influenza fusion i nhibitor, is reported. Tritiation of a mixture of N-(t-butoxycarbonyl)-1,3, 3-trimethylcyclohex-4 (or 5)-enylmethylamine via T-2 and Pd/C, followed by coupling of the deprotected tritiated amine with acetyl 5-azidosalicylic ac id chloride yielded the penultimate product. Subsequent deprotection and no rmal phase HPLC purification yielded the target compound with a radiochemic al purity >99% and a specific activity of 63 Ci/mmol.