Purification Methods
Dissolve DEAD in toluene, wash it with 10% NaHCO3 till neutral (may require several washes if too much hydrolysis had occurred: check IR for OH bands), then wash with H2O (2x), dry over Na2SO4, filter, evaporate the toluene and distil it through a short Vigreux column (p 11) at as high a vacuum as possible. The main portion boils at 107-111o/15mm. Since it is likely to explode, use an oil bath for heating the still and all operations should be carried -out behind an adequate shield. [Rabjohn Org Synth Coll Vol III 375 1955, see Kauer Org Synth Coll Vol IV 412 1963]. [Beilstein 3 III 233.] It is commercially available as a 40% solution in toluene. This reagent is useful in the Mitsunobu reaction [Mitsunobu Synthesis 1 1981, Gennari et al. J Am Chem Soc 108 6394 1986, Evans et al. J Am Chem Soc 108 6394 1986, Hughes Org React 42 335 1992, Dodge et al. Org Synth 73 110 1996, Hughes Org Prep Proc Int 28 127 1996, Ferguson & Marcelle J Am Chem Soc 128 4576 2006; see also di-tert-butyl azodicarboxylate above and DIAD below]. § A polystyrene supported DEAD version is commercially available with a loading of ~1.2mmol/g.
