Aromatic Substitution. XXXV: Boron Trifluoride Catalyzed Nitration of Benzene, Alkylbenzenes, and Halobenzenes with Methyl Nitrate in Nitromethane Solution
Part XXXIV: G. A. Olah and H. C. Lin, J. Amer. Chem. Soc., 96, 549 (1974).
The competitive rates and isomer distributions of the BF3 catalyzed nitration of benzene, alkyl-, halo-, and substituted polymethylbenzenes with methyl nitrate in nitromethane solution were determined. Relative nitration rates of alkylbenzenes were shown to correlate more closely with the stability of the corresponding π complexes, than those of the σ complexes. This trend is greatly enhanced with increasing alkyl substitution. Relative rates of nitration of substituted benzenes, 3-substituted toluenes, 2-substituted p-xylenes, and 3-substituted durenes were correlated with help of the Yukawa–Tsuno equation. The correlation of r values with the nature of the involved transition states is discussed.
