Kinetics and Mechanism of Chlorination of Acetanilide and Substituted Acetanilides by Chloramine-T

Department of Chemistry, Berhampur University, Berhampur-760 007, Orissa

Manuscript received 2 January 1919, revised 13 November 1980, accepted 10 March 1981

Kinetic of chlorination of acetanilide and substituted acetanilides fn (20% HOAc - 80% H₂O) medium In presence of perchloric acid and hydrochloric acid are reported. The order with respect to CAT (0.00025 to 0.0025M) Is unity. The reactions are found to be acid catalysed. The order with respect to substrate has been found to be fractional In the range (0.002 to 0.02M) studied. Added chloride ions (0.003 to 0.025M) have pronounced catalytic effect.

A mechanism involving the formation of N-chloro intermediate in an equilibrium step followed by intermolecular Orton rearrangement In rate determining step has been postulated. The rate laws consistent with the observations have been discussed.

Activation parameters at 60^o have been computed and for acetanilide, p-methyl acetanilide, p chloroacetanilide and o-chloroacetanilides the \(\bigtriangleup\)E^#'s are 15.25k cal/mole, 14.08 k cal/mole, 15.25 k cal/mole and 17.60 k cal/mole respectively and \(\bigtriangleup\)S^# are -32.95 e.u., -36.69 e.u., -33.71 e.u. and -27.05 e.u. respectively.