What do you mean by *every* GBL synthesis--I guess you mean every aqueous phase GBL synthesis? (e.g. from THF or GABA)
You can use any non-polar that is fairly polar... e.g. diethyl ether, ethyl acetate or DCM. I think ethyl acetate would be the best of the bunch, but I never tested it. Do not use heptanes, toluene, xylene or any other solvent that is very non-polar.
These solvents are all OTC and are recycled in the extraction of GBL... so I don't know what you're complaining about... you're not talking about using large amounts of solvents.
If you're talking about going GABA->GBL, a tried, tested and true method... then...
If you distill down the water volume until you get a sat sol'n of brine (if using HCl as the acid)... then you can extract with less solvent... or you could go to near dryness, then add methanol and filter, wash the precipitate with more methanol... then distill off the alcohol to get crude GBL to distill (avoiding any non-polar used)...
Keep in mind that the water distilled off with contain *about* 1g GBL / 10ml solution, and there's lots of "bumping" that will go on in the flask on the way to dryness.
