Reactions of Azolium cations. II [1]. Regioselective N2 alkylation of 5-aryltetrazoles with isopropyl alcohol in sulfuric acid media: Effect of electronic properties of aryl substituents on the reaction rate
✍ Scribed by A. O. Koren; P. N. Gaponik; V. A. Ostrovskii
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 315 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0538-8066
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✦ Synopsis
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". The true rate constants were evaluated, logarithms of which were found to correlate with (ro constants of phenyl substituents as log k = -0.488 u o -0.417. Small value of Hammett constant p 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.