Reaction of phosgene with aluminium III bromide

The treatment of aluminium(III) bromide with an excess of phosgene at salt-ice temperatures gives an initial lively reaction which, upon warming to 15 C, proceeds in a vigorous second stage to give COClBr [2127]  

This reaction clearly proceeds via an unstable low temperature intermediate, probably [CljCO-iAlBrj], which decomposes at 15 C [2127]. 

A preliminary study of the COClj-GaQ3 system, by tensimetric titration at both 0 C and -35 C, indicates the formation of a 2 1 adduct, which dissociates without any evidence for the formation of a 1 1 complex [ICIl]  

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It is also interesting to note that the mixed carbonyl halide, COBrCl, has been prepared by the reaction of phosgene with aluminium(III) bromide (see Section 9.1.2.6) [2127] ... 

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