Synthesis of phenolic esters with potential long-lasting insect-repellent properties

The synthesis of undecanoic acid esters of resorcinol, 4-chlororesorcinol, hexachlorophene, o-chlorophenol, and p-chlorophenol is described. The compounds were designed to provide, potentially, perdurable insect-repellent activity. When the synthesis of esters of resorcinol and 4-chlororesorcinol was attempted with undecanoic acid, under acid catalysis, principally ketones and ketoesters were isolated. The originally sought esters were obtained, however, by the reaction of the phenols with undecanoyl chloride in the presence of pyridine. The infrared, nuclear magnetic resonance, and mass spectra of the compounds are discussed.