Catalyzed Thermal Decomposition of Organic Acids: Part 2.—Catalyzed Decomposition of Cyclopentane- and Cycloheptane-carboxylic Acids by Hydrogen Bromide

Abstract

Cyclopcntanc- and cycloheptane-carboxylic acids decompose by a molecular mechanism into carbon monoxide, water and the corresponding alkene on catalysis by HBr in a seasoned Pyrex vessel. The decomposition is homogeneous and first order in acid and catalyst, HBr. The second order rate constants, expressed by the Arrhenius equations are: k2 = 1012.17e-29 550/RTcm3mol-1 s-1 for cycloheptanecarboxylic acid and k2 = 1013.49e-34 590/RTcm3mol-1 S-1 for cyclopentanecarboxylic acid over the temperature range 369.0-434.0°C (R in cal mol"1).