GAS PHASE THERMOLYSIS OF N-(TERT-BUTYLTHIO)ALLYLAMINE AND N-(TERT-BUTYLTHIO)DIETHYLAMINE

Article abstract of DOI:10.1002/poc.610071102

The title sulphenamides were pyrolysed in a stirred-flow reactor at temperatures of 310-410 deg C, pressures of 8-15 Torr and residence times of 0.4-2 s using toluene as the carrier gas.N-(tert-Butylthio)allylamine formed 73 +/- 4percent isobutene, 23 +/- 3percent propene and N-allylthiohydroxylamine.The first-order rate coefficients for the formation of isobutene and propene, respectively,followed the Arrhenius equations k_C4(s^-1) = 10^{12.52 +/- 0.36} exp(-163 +/- 5 kJ mol^-1 RT) and k_C3(s^-1) = 10^{10.99 +/- 0.29} exp(-151 +/- 4 kJ mol^-1 RT).N-(tert-Butylthio)diethylamine gave 97 +/- 1 percent isobutene, 1.9 +/- 0.4 percent isobutane and N,N-diethylthiohydroxylamine.The first-order rate coefficients for isobutene elimination followed the Arrhenius equation k(s^-1) = 10^{13.45 +/- 0.24} exp(-164 +/- 3 kJ mol^-1 RT).The formation of the products is interpreted in terms of an elimination reaction with a unimolecular, four-centered, cyclic transition state.The reactivity of these sulphenamides was found to be much higher than that of previously studied alkyl or aryl tert-butyl sulphides and disulphides.