Kinetics of regioselective N2 alkylation of a series of 5-(R-phenyl)tetrazoles with isopropyl alcohol has been studied in 88.2, 94.3, and 98.3% (w/w) sulfuric acid at 25 degrees. The true rate constants were evaluated, logarithms of which were found to correlate with sigma degrees constants of phenyl substituents as log k = -0.488 sigma degrees - 0.417. Small value of Hammett constant rho is evidence of a considerable isolation of the reaction center from the influence of the substituent at position C5 of the heteroring. This conclusion is confirmed by results of MNDO quantum chemical calculations of a series of 5-substituted tetrazolium cations. A correlation between logarithms of the true rate constants and the calculated net effective charges on atoms N2(N3) for 5-(R-phenyl)tetrazolium cations has been revealed. (C) 1995 John Wiley & Sons, Inc.
