GB620855A - Improvements in the manufacture of bromine-containing compounds - Google Patents

Abstract

Bromine-containing compounds are obtained by reacting an olefine compound, in which, if present in a carbocyclic structure, the double bond is not conjugated with any other double bond within the carboxylic structure, with a bromomethane containing at least three halogen atoms, either by irradiating with actinic light, or by heating in the presence of a diacyl peroxide at its decomposition temperature. Preferred bromomethanes are carbon tetrabromide and bromoform, but other members of the class which may be used are CBr2ClH, CBrCl2H, CBr3Cl, CBr2Cl2, CBrCl3, CBr2F2, CBrF3, CBr3F. The olefinic compound may be represented as <FORM:0620855/IV (b)/1> where R1, R2, R3, and R4 are either hydrogen, alkyl, polymethylene, aryl, substituted alkyl, or halogen radicals, where any two R's may be linked to form a non-aromatic ring. Specified compounds are cyclohexene, butene-2, oleic acid and esters, propene, butene-1, isobutylene, vinylcyclohexane, a -methylstyrene, methallyl acetate, allyl chloride, vinyl acetic acid, and allyl ethyl ether. It is preferred to have both R1 and R2 hydrogen. A solvent may be used, e.g. benzene or carbon tetrachloride, and it is desirable to do so when the reaction is catalysed by the thermal decomposition of a peroxide, e.g. acetyl peroxide. In examples 1-6, carbon tetrabromide is reacted with the following unsaturated compounds by heating at Ca. 70 DEG whilst irradiating with actinic light: n-octene-1, ethylene, styrene, isobutylene, allyl acetate and undecylenic acid. In examples 1 and 7, bromoform is reacted with n-octene-1 by heating at 80 DEG C. in presence of acetyl peroxide.