Gas phase thermolysis of aryl t ‐butyl amines

N ‐ t ‐butylaniline, N ‐ t ‐butyl‐ p ‐anisidine, and N ‐ t ‐butyl‐ p ‐nitroaniline have been pyrolyzed in a stirred‐flow reactor at 510–620°C, 8–15 torr total pressure, and 0.5–1.5 s contact time, using toluene as carrier gas. An order one kinetics was observed for the consumption of the amines. The reactions yielded 95 ± 2% isobutene plus the corresponding anilines as reaction products. The rate coefficients followed the Arrhenius equations N–t –butylaniline\documentclass{article}\pagestyle{empty}\begin{document}$$ k = 10^{14.19 \pm 0.32} \exp (- 234 \pm 5\,{\rm kJ/mol}\, RT) $$\end{document}N‐t ‐butyl‐ p ‐anisidine\documentclass{article}\pagestyle{empty}\begin{document}$$ k = 10^{13.05 \pm 0.23} \exp (- 208 \pm 4\,{\rm kJ/mol}\, RT) $$\end{document}N‐t ‐butyl‐ p ‐nitroaniline\documentclass{article}\pagestyle{empty}\begin{document}$$ k = 10^{13.73 \pm 0.28} \exp (- 235 \pm 6\,{\rm kJ/mol}\, RT) $$\end{document}The results are consistent with an unimolecular elimination of isobutene involving polar four‐center cyclic transition states. © John Wiley & Sons, Inc.