Preparation and some reactions of halomagnesium diorganocuprates

Bromomagnesium diphenylcuprate and iodomagnesium dimethylcuprate have been prepared, and their thermal stability and some of their reactions investigated. In diethyl ether, 50% of the BrMgPh₂Cu decomposes in 12h at room temperature and 50% of the IMgMe₂Cu decomposes at 0°C in 14 but the cuprates are more stable in THF at or below 0°C. They react with acid chlorides to give 16–76% yields of the corresponding ketones. With bromine and iodine, BrMgPh₂Cu gives bromobenzene and iodobenzene in 56 and 48% yield, respectively. Oxidation of BrMgPh₂Cu with nitrobenzene or copper(II) chloride gives, respectively, 61 and 34% of biphenyl. Reaction of BrMgPh₂Cu with acetic or benzoic anhydride yields 46–55% of the corresponding ketone and 34–37% of the corresponding carboxylic acids.