Electrophilic Aromatic Substitution. 5. A Kinetic Study of the Friedel-Crafts Acylation in Nitromethane

Article abstract of DOI:10.1021/jo00195a015

Noncompetitive kinetic studies were made of the AlCl3-catalyzed reaction of 2,4-dichlorobenzoyl chloride with benzene and with toluene in nitromethane at 20 deg C.The reaction appears to follow the kinetic expression: rate = (k/₀).The k_T/k_B = 472 +/- 84 and product isomer distribution (8.4 +/- 0.3)percent ortho, (0.43 +/- 0.02)percent meta, and (91.2 +/- 0.3)percent para are in good agreement with the Brown selectivity relationship but unexpectedly indicate a weak rather than strong electrophile.This appears to be an artifact of the inverse rate order dependence upon initial AlCl3 concentration.