Iodine → 1,1-Diphenylethylene

Participants

Reaction Steps

Into a reactor were introduced 31.6 g (1.30 mol) of magnesium and 50 mL of THF under a nitrogen atmosphere. Iodine and ethyl bromide were added to the mixture in a slight amount to ascertain initiation of a reaction. Thereafter, 600 mL of THF was added thereto, and methyl chloride gas having a regulated temperature was bubbled into the resultant mixture at a regulated rate so as to keep the mixture at 30 to 40° C. After heat generation ended and the magnesium metal was ascertained to have disappeared, the reaction mixture was stirred at that temperature for 1 hour. Subsequently, a mixture of 182 g (1.10 mol) of benzophenone and 364 mL of THF was gradually added dropwise thereto at 35 to 40° C. and this mixture was stirred for 15 hours. This reaction mixture was cooled and then poured into 10% aqueous ammonium chloride solution. The resultant mixture was stirred for 30 minutes. After liquid separation, the organic layer was washed with an aqueous sodium chloride solution and water, subsequently dried with anhydrous magnesium sulfate, and then concentrated under reduced pressure. To the concentrate were added 400 mL of toluene and 1 g of p-toluenesulfonic acid monohydrate. The resultant solution was subjected to azeotropic dehydration for 2 hours with toluene refluxing. After being cooled, the reaction mixture was washed with 2% aqueous sodium carbonate solution and water and then dried with anhydrous magnesium sulfate. Thereafter, the solvent was removed under reduced pressure. The concentrate was purified by distillation to obtain 174 g (97%) of the target compound.

Provenance & Evidence