| Abstract: | The kinetics of 2-bromo-3-methylbutyric acid in the gas phase was studied over the temperature range of 309.3–357.0°C and pressure range of 15.5–100.0 torr. This process, in seasoned static reaction vessels and in the presence of the free radical inhibitor cyclohexene, is homogeneous, unimolecular, and follows first-order rate law. The observed rate coefficients are represented by the following Arrhenius equations: log k1(s?1) = (12.72 ± 0.25) ? (181.8 ± 2.9) kJ mol?1 (2.303RT)?1. The primary products are isobutyraldehyde, CO, and HBr. The polar five-membered cyclic transition state type of mechanism appears to be preferred in the dehydrohalogenation process of α-haloacids in the gas phase. © 1995 John Wiley & Sons, Inc. |
