gypsyNo2 - 5-6-2012 at 21:57
Hey Guys,
Am working on something at the moment and I am using a slightly modified Knoevenagel condensation to give me aromatic, alpha, beta unsaturated
carboxcylic acids (http://dx.doi.org/10.1080/17518250802141200) and am having trouble purifying them.
I am reactting (all in molar eq) piperonal, malonic acid, ammonium formate in pyridine. Microwaved at 300W for about 2 minutes.
Have tried acid/base extraction but I keep getting this ultra fine powder which is hard to filer. have also tried simply washing the reaction contents
with water but nothing seems to give me a decent looking compound (impurities galore).
Any ideas ?
Cheers
GypsyNo2
Hexavalent - 5-6-2012 at 23:58
Have you tried looking for a suitable solvent and recrystallizing your compound slowly?
gypsyNo2 - 7-6-2012 at 15:18
I have trialled a few, looks like DSMO/Water are a go but it tends to drop out as a powder which is just hard to deal with
Hexavalent - 7-6-2012 at 15:50
Sadly, that's the nature of some compounds.
You could also try cooling slowly in a gently warmed Thermos flask, or dissolve the compound into solvent and allow it to evaporate very slowly at RTP
or maybe in a dessicator.
gypsyNo2 - 7-6-2012 at 19:51
Yeah cheers Hex, might give that a go, thanks mate.
Gyp
Hexavalent - 8-6-2012 at 13:21
You're welcome, give it a go and report back with your findings