GAS-PHASE REACTION OF ACETIC ACID WITH HYDROGEN BROMIDE

In the gas phase, acetic acid reacts with hydrogen bromide in the temperature range 412–492° to give methyl bromide, carbon monoxide, and water. The reaction is first order in each reagent, and the variation of rate constant with temperature is described by the equation k2 = 1011.67exp(−30400/RT) ml mole−1 sec−1. Possible transition states for the reaction are examined. A mechanism involving an intermediate of the type CH3CO+Br− is possible if the reaction is of the family represented by the hydrogen bromide catalysed decompositions of trimethylacetic, isobutyric, and propionic acids. © 1969, CSIRO. All rights reserved.