Free-radical substitution in aliphatic compounds. Part XIV. The halogenation of esters of butan-1-ol

Abstract

The chlorination of n-butyl formate, acetate, and trifluoroacetate, and the bromination of n-butyl acetate and trifluoroacetate have been studied in the gas phase by use of a static system. Chlorination is appreciably deactivated at the 1-position and slightly in the 2-position. Bromination is activated at the 1-position and slightly deactivated at the 2-position. From halogenations at a range of temperatures approximate Arrhenius parameters have been calculated for attack at each site. The difference in reactivity of different positions is principally determined by differences in activation energy although the pre-exponential factors for the substituted position are invariably lower than for the 4-position. The results are considered in terms of current theories.