An NMR study of the equilibria involved with benzotriazole, carbonyl compounds, and their adducts

Abstract

A ¹H and ¹³C NMR study of the equilibrium mixtures of benzotriazole and several carbonyl compounds with their adducts, in [²H₆]benzene and other solvents, affords the equilibrium constants for the reversible formation of N-1 (K₁) and N-2 (K₂) isomeric adducts. Thermodynamic parameters have been computed. Adduct formation is generally less predominant in sterically crowded cases. In general the N-1 isomer predominates over the N-2 isomer, however, with the sterically hindered 4,7-dimethylbenzotriazole this order is reversed.