The acyl cyanides were prepared according to the procedures reported previously (5) : a mixture of 1,0 mol. of acyl chloride and 1,0 mol. of cuprous cyanide in acetonitrile (400ml), is heated under reflux during 20 mn. It has now been found that deleterious side reactions can be minimized by rapidly distilling out the excess acetonitrile and crude products under vacuum. This crude distillate was then carefully refractionated to yield 80 % acyl cyanide. For others synthetic ...