1,1-diiodoethane

1,1-diiodoethane is a reagent for methylcyclopropanation of alkenes and ethylidenation of carbonyl compounds.

Journal of the American Chemical Society, 73, p. 4476, 1951 DOI: 10.1021/ja01153a524

The Preparative Methods of 1,1-diiodoethane: mix 39.6 g (0.40 mol) of 1,1-dichloroethane, 187 g (1.2 mol) of ethyl iodide, and 2.0 g of Aluminum Chloride and heat on a steam bath for 3 h; wash the mixture with H2O and then NaHSO3, and dry over MgSO4; distillation provides 67.3 g (60%) of the product 1,1-diiodoethane boiling at 75-76 °C/25 mmHg. An alternative procedure utilizes the reaction of Iodine, Triethylamine, and the hydrazone of Acetaldehyde: from 1 mol of acetaldehyde, 95 g (34% from acetaldehyde) of 1,1-diiodoethane can be isolated; this procedure is a little more involved but provides a viable alternative if 1,1-dichloroethane is not available.

Corrosive and irritant; emits toxic fumes if heated to decomposition or mes in contact with acids. Use in a fume hood; store over copper powder and protect from light.