Phosphorus trichloride [7719-12-2] M 137.3, b 76°, d 1.575, n 1.515. Heat it under reflux to
expel dissolved HCl, then distil it. It has been further purified by vacuum fractionation several times through a
-45° trap into a receiver at -78°. [Forbes Inorg Synth II 145 1946.] HARMFUL VAPOURS.
Perrin 6th ed p 482
Doesn't mention doing distillation under N2/vacuum but I would. If distilling at RT
attach outlet to drying tube with KOH pellets?