Kinetics, catalysis, and mechanism of isomerization of N ‐[(benzotriazol‐1‐yl)methyl]anilines into the benzotriazol‐2‐yl derivatives

The 1 H NMR technique was applied for the measurement of the isomerization rates of N ‐ethyl‐ N ‐[(benzotriazol‐1‐yl)methyl]aniline ( 4 ) and 4‐butyl‐ N ‐[(benzotriazol‐1‐yl)methyl]aniline ( 7 ) to the corresponding benzotriazol‐2‐yl isomers in dioxane‐d 8 at 35°C. The rate constants obtained for pure dioxane‐d 8 were 1.62 and 0.28 h −1 for 4 and 7 , respectively. For both compounds, addition to acetic acid to the dioxane solutions accelerated the isomerizations whereas addition of triethylamine retarded it strongly. Addition of water slowed the isomerization of 4 but accelerated that of 7 : the different effects operating in the two cases are discussed and rationalized. © 1995 John Wiley & Sons, Inc.