I need to add an organic compound in the liquid medium as a sole carbon source (for microbial degradation study) but without autoclaving the compound. The compound has a very low water solubility of ~600mg/l and remains undissolved unless the media is heated. To avoid autoclaving the compound along with the media one way is to filter sterilize the compound, though it would require a large volume and the process would become impractical if I need to work at higher concentrations of the compound.
Can I add my compound dissolved in acetone or any other low boiling point solvent in the liquid media (after autoclaving ii). Since the boiling point of acetone is 56 degree and if I add the compound (in acetone) in the hot media (70-80 degree celsius), will it eliminate all the acetone (since I don't want any additional carbon source)?
P.S.: I tried the above method and I let the media bottle open for about an hour. Though I could still smell acetone in it.
Also, what can be the negative impacts if I autoclave the compound (it is generally avoided)? My compound is an aniline derivative.
If you do not have some sort of emulsifier, once you remove the acetone or alcohol (which in this case acts as a phase transfer catalyst), nothing will keep your organic compound from separating from the water. If you autoclave it, depending on your pH and so on, the aniline can react with acetone.
I'm not sure your evaporation trick will work as you will always have some trace solvent left behind if it's water-miscible. You could try moving to an extremely low-boiling organic solvent such as methyl formate (BP = 32 C). Otherwise, if the exact identity of the compound is not important, your best bet would be to modify it with a solubilizing group such as an alkyl sulfate or PEG chain.
Hi, what I would recomendo you to do are two things: You could either add some DMSO so your organic compound (the less volumne you can) and then make dilutions, or try to make a salt ofo your organic compound; por example .HCl, that would increase the solubility and there won´t be necessity to add any other solvent. Hope that works to you
If a co-solvent like acetone solves the dissolution problem (and assuming you don't need more than 600 mg/l of the compound), you can remove the acetone by boiling it off as the water-acetone azeotrope. If you don't want to heat your solution to 100ºC, you can pull a vacuum on it and boil at a lower temperature. This may not work a very low pressures (azeotrope curves vary quite a lot with pressure), but you should be good down to at least 0.5 atm.
Thank you all for your valuable suggestions. Certainly, boiling acetone in a vacuum is an efficient technique. Though I don't want to add any other organic solvent like DMSO (as it has a higher boiling point and has carbon in it). The reason for evaporating acetone is to remove any probable traces of carbon.
Hi Ibrahim, I would suggest looking at Org Syn if you need a reliable prep for piperidine-2,6-dione (glutarimide).
http://www.orgsyn.org/demo.aspx?prep=CV4P0496
Autoclaving an aniline can lead to oxidation of the compound. You could try to avoid this by inerting the autoclave. What concentration do you want to end up at in the media?
Any one can help me in chemical synthesis of 3-aminopiperidine-3,6-dione?
Please check the numbering of that compound. Something doesn't seem right to me.
For your compound of limited solubility, as the soluble part is consumed, more will go into solution. Also, it appears that some heat is acceptable. What is the solubility at 79 or 80 C? What is the maximum temperature that you can use? Acetone added to 80 C water will largely flash off, but some will be retained, but I cannot give you a quantitative figure.
Dr. Paul, the compound is stable and does not get readily oxidized, unlike other anilines (It is a stable compound). I autoclaved the compound and took the TLC after it. The TLC spot was corresponding to the original spot. I am working at 300 uM concentration. The compound only gets dissolved on heating the media (the media is a phosphate buffer, though with very less concentration). I want to work with 1mM concentration. However, if the compound does not dissolve I will work at a lower concentration.
Dr. Kirk, The solubility of the compound is around 600mg/L at 25 C. As you mentioned, acetone will flash off at 80 C but it will not be completely removed (The reason of adding acetone at the first place was to increase the water solubility. If I somehow manage to remove all the acetone will it not lead to precipitation of the compound?). So I won't mind the temperature unless my compound decomposes.
The reason for evaporating acetone was to remove any additional carbon source. I can use vacuum evaporation methods as Dr. James mentioned though it might increase the chance of microbial contamination. So, If TLC is suggesting that after autoclaving there is no shift in the spot. Can I go with it?
Sounds like autoclaving is the best answer. As for the low solubility it should still be sufficiently soluble for your study. You will always have around 600mg/ml in solution for the microbes to chew on.
Dissolve in something like dymethylformamide, terahydrofurn or dymethylsulfoxide and add to water
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