n-butyllithium in diethyl ether byproducts: LiI, n-butane; addn. of n-BuLi in Et2O into a soln. of COT in Et2O within 0.5 h at room temp. with stirring, 1 h, dark cherry-red soln., react. vessel filled with Ar, addn. of UI3 at 273 K, stirring for 3 h; evapn. (vac., room temp.), repeated sublimation (540 K, 1E-2 Pa); identified by comparison of UV, IR, 1H NMR and mass spectra with published data;