A laboratory synthesis described for iodobenzene starting from benzene and iodine. The sequence includes forming nitro intermediates by reacting benzene with iodine in concentrated nitric acid under reflux, reducing the nitro compounds to aromatic amines with tin in hydrochloric acid, separating and purifying the organic phase, and distilling to obtain iodobenzene. The final product is a pale yellow liquid with a reported yield of about 81% from starting iodine, and it serves as a precursor to phenylmagnesium reagents. Safety notes highlight benzene's carcinogenic risk and the toxic nitrogen dioxide produced, requiring good ventilation during the reaction.
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