DMF is much less soluble in ether than it is in EtOAc or DCM
I thought DMF had a high affinity for DCM, actually, for some reason. Wasn't that how someone blew up their lab awhile back? Like, they tried to get rid of DCM by rotovaping it off with DMF, and it didn't work even though the boiling points are like 100°C different?
"(R)-1-(6-(Benzyloxy)indazol-1-yl)-2-propanol (1, 1.26 kg, 4.45 mol) was converted to mesylate 2 under standard conditions as indicated.(21) After an aqueous quench and phase separation the organic solution was concentrated on a rotary evaporator of 20-L capacity. The dual receiving flasks were then emptied. DMF (4 L) was added to the residue, and concentration (35 °C bath, 20 Torr) was resumed until no further condensation was observed, the intention being to drive off DCM from the product. The residual solution of 2 was diluted with more DMF (12 L) and transferred to a reaction flask. Sodium azide (580 g, 8.9 mol) was added, and the stirred mixture was heated to 70 °C for 16 h, then cooled to rt and partitioned between diethyl ether and water. The organic extract was concentrated on the evaporator, and the receivers were then emptied.
The next morning it was noted that about 30 mL of a two-phase liquid had collected in the glass crosspiece at the bottom of the condenser assembly. The distilling flask containing azide 3 was disconnected and set aside in a walk-in fume hood, and the PTFE stopcock leading to one of the receivers was then opened to drain the liquid. Within seconds a loud explosion occurred. The plastic-coated condenser and receiving flasks shattered. Larger glass fragments were propelled with sufficient force to break other glassware. A 2′ square perforated metal ceiling vent cover above the evaporator was domed by pressure, while a 4 1/2′ × 8′ × 1/4″ annealed glass window panel located 20′ away was fractured by pressure or impact. Two chemists sustained noncritical lacerations but escaped more serious injury, principally by the proper wearing of safety glasses."
I wish I could get my lab accidents published in OPRD. Guess they don't involve enough exploding rotovaps.