118738-95-7Relevant academic research and scientific papers
Protiodeacylation of 4-Substituted 1-Acetyl-2,6-dimethylbenzenes in Sulphuric Acid: Kinetics and Mechanism
Al-Ka'bi, Ja'far,Farooqi, Jameel A.,Gore, Peter H.,Nassar, Ahmed M. G.,Saad, Esmat F.,at al.
, p. 943 - 950 (2007/10/02)
In 89.8percent (w/w) sulphuric acid rate coefficients (1E4k1/s-1) for the protiodeacetylation of 4-substituted (X) 1-acetyl-2,6-dimethylbenzenes (1) were, at 25 deg C; X=Br, 0.468; I, 0.509; Cl, 0.635; H, 1.345; F, 2.52; Ph, 31.5; t-Bu, 38.6; and Me, 47.2.At 25 deg C the reaction of the ketone (1; X=OMe) was too fast, and at 80 deg C reactions of the ketones (1; X=CONH2 or CO2H) were too slow, for convenient measurement.The carboxy nitrile (X=CN) underwent hydratation to the amide (X=CONH2) rather than protiodeacetylation.The rate coefficients at 25 deg C of eight ketones (1) gave an accurate Hammett correlation, with ?+ constants, giving ρ = -4.64+/-0.05.The reaction of 1-acetyl-2,4,6-trimethylbenzene (1; X=Me) was studied of a range of acidity (73.6-99.9percent sulphuric acid), and a maximum was found near 86.0percent acid.Rates were also measured in D2SO4-D2O.The mechanism is discussed.
