The addition of chlorine and chlorine-bromine mixtures to cinnamic acids

Abstract

The work in the present thesis is a continuation of that included in a thesis for M.Sc. (1937). The previous work dealt with addition of chlorine, and to some extent bromine chloride; the aim of this work was to extend our knowledge of chlorine addition and to investigate in some detail the kinetics of iodine chloride addition including such additions of other halogens as appeared to be necessary for the general interpretation of the results obtained. No new literature has appeared dealing with chlorination but a series of papers by Urushibara and Takebayashi (1,2), show that the addition of bromine to cinnamic acid in carbon tetrachloride is a reaction which exhibits the "oxygen effect" such as was found by Kharasch (3) and shown by him to be present in hydrogen bromide additions. When oxygen is removed very carefully the reaction proceeds quite rapidly and the workers maintain, on rather slender evidence, that the reaction is homogeneous. If oxygen has such a pronounced effect on this reaction, it is to be expected that many similar processes including the analogous chlorination may be of a similar type. The difficult and involved experimental technique required would make such work very difficult, especially if chlorine is used.