Pyrolysis of phenylmercaptoacetic acid

Abstract

The pyrolysis of phenylmercaptoacetic acid was investigated by the toluene-carrier technique over the temperature range 760-835 OK. 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: klReaction [I] was shown to be a homogeneous first-order dissociation process, and its rate constant was represented by the expression k l = 1.0 x 1015 exp (-58000/RT) s-1.The activation energy of this reaction, i.e. 58 kcal/mole, was identified with D(C6H5S-CH,COOH).

Pyrolysis of hydrocinnamic acid

“…The apparatus and procedure used were identical with those employed for the pyrolysis of phenylmercaptoacetic acid (1). Toluene was passed through the reaction vessel for 5 min both before and after the reaction to ensure that no pyrolysis of toluene alone occurred under the present experimental conditions.…”