[rjb]

Hi there,

It has (once again) been rather a long time since my last post, but recollecting the level of collective knowledge available on here, I thought if anyone would know the answer to the following, the good folk of chemical forums certainly would!

I am currently working on a project involving a mixture containing seven known organic compounds (at moderate PPB levels) which will be dissolved in an organic solvent. I have free reign over the choice of solvent used and beyond the obvious feature (i.e. solubility), I am looking for something fairly volatile, reasonably innocuous and which will not react with the compounds present in my mixture; although this is something that will ultimately be revealed during a stability testing phase.

This stability point is an interesting one and I am struggling to find any resources which allow a 'rough and ready' determination of solvent in/compatibility with compounds containing particular functional groups - I would obviously prefer to deselect anything that has the potential to cause me issues before doing the work! I am fairly familiar with the idea that ketones (like acetone) can cause issues with amines due to imine/enamine formation, but beyond this I can’t seem to find anything that gives a ‘thou shalt not use solvent X with anything containing functional group Y’ proclamation and wondered if such a thing exists or not?

In this case Google is not my friend and yields vast swathes of content about stability of plastic consumables or storage of incompatible compounds, but beyond that nothing. Is anyone able to suggest a possible resource please?

For the record, my mixture contains compounds with the following groups:

•   Carbamide - In this case centralites
•   Nitrate Ester
•   Secondary and Tertiary Amine
•   N-Nitroso
•   Nitro

Many thanks for your time

Kind Regards

R

[rolnor]

Ethyl acetate? Secondary amines react but slowly, could be a problem. Its cheap, volatile and non-toxic.

[Babcock_Hall]

Nitrate esters are labile to base, by three mechanisms of which I am aware.  I mention this only because it seems to me that impurities in the solvents might be as big a problem as the solvents themselves.

[kriggy]

It has (once again) been rather a long time since my last post, but recollecting the level of collective knowledge available on here, I thought if anyone  a ‘thou shalt not use solvent X with anything containing functional group Y’ proclamation and wondered if such a thing exists or not?

It does not exist, its fairly context dependant.
I guess you need to do some experimentation but MeOH, diethylether or THF seem to worth trying

[rjb]

Many thanks for the great replies so far.

I feared that there probably wouldn't be any kind of hard and fast rules about solvent compatibility, but I think it was worth asking the question just in case there was something I had overlooked!
I plan on comparing 3 different solvents in the project, so there is scope for getting things a bit wrong, but obviously I would prefer to avoid selecting something stupid if I can. 

A lot of what has been said is really helpful and has given me a bit of confidence in the thoughts I had had thus far. Methanol is certainly on my list, along with an ether, although I was thinking perhaps MTBE rather than diethyl ether - which is not terribly popular with our Health and Safety people and will end up in an argument which is best avoided. Ethyl acetate was another one which I had considered and might well be OK given that I will also be looking at stability in various storage conditions. I can't imagine too much of an issue at -20?!

THF was something I hadn't considered at all and shall give this a bit of thought. With or without BHT, this might work quite nicely for what I was considering.

BH's comments on impurities make lot of sense so I shall pay heed to that and plan on doing bit of research on common contaminants and will use HPLC+ grade reagents.

Many Thanks

R

[rolnor]

For some reason I thought you should extract these from water solution, since you are not ethyl acetate is not my first choice, MeOH or EtOH will be fine.