AbstractThe pyrolysis of gaseous neopentyl bromide to 2‐methyl‐2‐butene, 2‐methyl‐1‐butene, and hydrogen bromide was studied under conditions of maximal inhibition by cyclohexene over the temperature range of 389−444°C. This reaction was shown to beconsistent with a first‐order homogeneous molecular process, with Arrhenius parameters ofE= 247 ± 5 kJ/mol and logA(sec−1) = 14.2 ± 0.3. Examination of the uninhibited reaction showed it to be a radical process, simpler than that with neopentyl chloride, there being only one propagation step, thedissociation of the γ‐radical to 1,1‐dimethylcyclop