Synthesis, kinetics and mechanism of cyclization of 1-(2-aryloxycarbonylphenyl)-3-phenyltriazenes

O Pytela, Z Bahník

Index: Pytela, Oldrich; Bahnik, Zdenek Collection of Czechoslovak Chemical Communications, 1990 , vol. 55, # 11 p. 2692 - 2700

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Abstract

Abstract Twelve substituted 1-(2-aryloxycarbonylphenyl)-3-phenyltriazenes have been synthetized and kinetics of their reactions have been measured in 52.1%(by mass) aqueous methanol at pH 3 to 11. Plots of k obs vs pH show three regions: noncatalyzed cyclization (pH 4 to 7), acid-catalyzed splitting of the triazene chain, and base-catalyzed cyclization. The non-catalyzed cyclization exhibits a kinetic isotope effect, the reaction constant ρ= 2.69 (σ- ...