3,5-Difluorobenzyl bromide → Diphenylacetylene

Participants

Reaction Steps

To a dry, round bottom flask was charged 0.43 mol 3,5-difluorobenzyl-bromide and 300 ml anhydrous tetrahydrofuran. The mixture was cooled under nitrogen atmosphere to 0° C. at which time a solution of 0.54 mol allylmagnesiumchloride in 270 ml tetrahydrofuran was slowly added keeping the temperature at 0° C. After allowing to warm to room temperature and stirring until completion (20 hours), the reaction was quenched with an excess of diluted hydrochloric acid. The organic layer was separated, and the aqueous layer extracted twice with petroleum spirits (2×75 ml). The organic layers were combined, washed with water (2×75 ml) and dried over anhydrous sodium sulphate. Removal of the solvent yielded 68 g of the title compound as a pale oil.

Provenance & Evidence