[go1010]

I'm trying to separate a mono-substituted dibenzothiophene (the substituent is an aldehyde) from DMF.  So far I've tried using THF and methanol, but neither worked.  Do you guys have any suggestions for a suitable solvent?  Thanks in advance for your help.

p.s.: it may be possible that there isn't any of the mono-substituted DBT present.

[Dude]

I believe dimethylformamide is water-soluble.   I would guess a thiophene derivative would not be water-soluble.  Try adding water and seeing if the thiophene material drops out of solution and then filter for a crude first separation.  Column chromatography is the best separation process for organic syntheses.  I would test silica gel with diethylether as the eluent for starters. My first recrystallization (assuming it is a solid) solvent attempt would probably be something like hexane.

[movies]

You ought to be able to wash most of the DMF out with a water/dichloromethane extraction, along the lines of what Dude said.  Otherwise, DMF should be a lot more volatile than the dibenzothiophene, so you could probably rotovap most of the DMF off.

[hemispheredancer]

Most often you get rid of DMF doing H2O/CH2Cl2 extraction.  You may need to wash the CH2Cl2 as many as 4 or 5 times to get rid of all the DMF.  DMF can be rotovapped but only if you have a real strong pump and you will have to heat it, its not as volatile as might think.

[movies]

FYI, b.p. of DMF is 153 degrees C, b.p. of dibenzothiophene is 332 degrees C.