Products and Kinetic Substituent Effects in the Reactions of Diaryldiazomethanes with 2,5-Dichloro-p-benzoquinone

Article abstract of DOI:10.1246/bcsj.55.551

Substituted diphenyldiazomethanes <(x-C6H4)2CN2; x = p-OCH3, p-CH3, H, p-Cl> were found to react with 2,5-dichloro-p-benzoquinone at its conjugated C=C and C=O bonds to give bicyclic diones and poly(2,5-dichlorohydroquinone benzhydryl ether)s recpectively, obeying the second-order kinetic low.The product ratios of the polyethers to the bicyclic diones increased from 1.1 to 8.1 with the electron-donating ability of the substituents.The individual rate constants were well correlated with the Hammett equation: log k₃ = -2.15-1.55? (r = 0.996) and log k₄ = -2.03-1.85 (?⁰+0.515Δ<*>_R⁺) (r = 1.00) for the bicyclic diones and polyethers processes respectively.The presence of methanol as a trapping agent stopped the polymerization completely and afforded the methanolysis product, though no essential change was found in the formation of the bicyclic dione.