Carbonyl bromide chloride from phosgene

The ethylidene, or unsymmetrical di-halogen substitution products of ethane, are not of much importance, because they do not easily undergo reaction. They are prepared by the reactions just described, viz., from aldehyde by the action of phosphorus penta-chloride, -bromide, or -iodide. Also by the action of phosphorus chlor-bromide, PCl3Br2, or of carbonyl chloride (phosgene), COCI2. They may also be made by the further halogenation of the mono-halogen ethanes ... 

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