Pyrolysis of phenylmercaptoacetic acid

The pyrolysis of phenylmercaptoacetic acid was investigated by the toluene-carrier technique over the temperature range 760-835 °K. The main products of the decomposition were phenyl mercaptan, carbon dioxide, acetic acid, phenyl methyl sulfide, carbon monoxide, and dibenzyl.The overall decomposition was a first-order reaction with respect to phenylmercaptoacetic acid and could be represented by the two parallel steps: Reaction [1] was shown to be a homogeneous first-order dissociation process, and its rate constant was represented by the expression The activation energy of this reaction, i.e. 58 kcal/mole, was identified with D(C 6 H 5 SCH 2 COOH).