The thermal decompositions of 2-methyl-2-phenoxypropane
The thermal reactions of 2-methyl-2-phenoxypropane have been studied in gas phase over the range 600-670 K by quadrupole mass spectrometry and pressure studies. The reaction is shown to be a homogeneous first-order elimination of phenol and 2-methylpropene which is described by the Arrhenius equation k = 1014.10�0.12exp[(-210.46�1.36)/RT] s-1 Possible reaction mechanisms are considered and the reaction is found to be a unimolecular elimination rather than a radical chain process initiated by homolysis to phenoxy and 1,1-dimethylethyl radicals. Evidence for the rearrangement to 4-t-butylphenol previously proposed has been carefully sought and it is concluded that the process does not occur in the gas phase. The A-factor observed for the reaction is in good agreement with that calculated for the four-centred transition state proposed for elimination of 2-methylpropene from alkoxypropanes.