The Dechlorination of Octachloronaphthalene by Naphthalene Radical Anions and Unsolvated Hydroxide lon

Abstract

Chlorine atoms in octachloronaphthalene (OCN) were almost completely removed as chloride ion when OCN was treated with Na dihydronaphthylide (Na⁺C₁₀H₈^-[I]) in THF. The minimum amount of[1] necessary to remove all the chlorine atoms was 1.2 mol/Cl (dechlorination efficiency: 99.1-99.8%). Other polychlorinated naphthalenes (technical grade) were also dechlorinated by the same procedure. When OCN was treated with a deficient amount of either C I J or K dihydronaphthylide (0.5 mol/Cl), the dechlorination efficiency exceeded 50% and reached 68-76% which could not be explained stoichiometrically. Comparing the reaction by unsolvated hydroxide ion with that by hydrated one, this was ascribed to the nucleophilic displacement reaction due to unsolvated (activated) hydroxide ion which was formed during the preparation ofCIin THF. Analysis of the products from the nucleophilic displacement of OCN is also described.