The gas phase elimination kinetics of the title compound was studied over the temperature range of 260.1-315.0ЊC and pressure range of 20-70 Torr. This elimination, in seasoned static reaction system and in the presence of at least fourfold of the free radical inhibitor toluene, is homogeneous, unimolecular and follows a first-order rate law. The reaction yielded mainly benzaldehyde, CO, and HBr, and small amounts of benzylbromide and CO 2 . The observed rate coefficients are expressed by the following Arrhenius equations: The mechanisms are believed to proceed through a semi-polar five-membered cyclic transition state for the benzaldehyde formation, while a four-centered cyclic transition state for benzylbromide formation.