Treat the borane with hex-1-ene and 10% anhydrous Et2O for 6hours at gentle reflux under N2, then distil it in a vacuum through an 18inch glass helices-packed column under N2 taking the fraction b 130o/2.1mm to 137o/1.5mm. The distillate may still contain some di-n-hexylborane [Brown & Subba Rao J Am Chem Soc 81 6423 1959, Mirviss J Am Chem Soc 83 3051 1961]. [Beilstein 4 IV 4362.]
