DEDE - Diethylene Glycol Diethyl Ether — Frequently Asked Questions

The two additional carbons on its end caps raise the boiling point and reduce water miscibility. That suits reactions run at higher temperature, and it makes aqueous work-up easier, since the fully water-miscible diglyme is difficult to separate from a water phase. Its cation-solvating power is somewhat lower than diglyme's for the same reason.

Yes. Both ends are capped with ethyl groups, so there is no hydroxyl and no active hydrogen. That makes it chemically inert toward organometallics, isocyanates and strong bases, which is the defining requirement for a reaction solvent used with those reagents.

Not necessarily, and this should not be assumed either way. Regulatory status varies within the glyme family and between jurisdictions, and DEDE is sometimes specified precisely because diglyme's position is an obstacle. Its own classification should be confirmed for the destination market before it is designed into a process.

Yes, like all ethers. It should be supplied inhibited, stored sealed away from light and air, dated on receipt and tested for peroxides before distillation. The risk is concentrated in distillation residues, so evaporation to dryness should be avoided without testing first.