Misc GHB conversion: getting rid of lactone smell

[tintincancan]

I've converted GBL to GHB a couple of times now using the NaOH method detailed on rhodium... the conversion has largely been successful, however try as I might I can't seem to completely get rid of a slight lactone smell, which is pretty undesirable.

Next time I do it I would like to crystallise it into "soap", and I want a very good product, so I definitely do not want any unreacted lactone in it.

In brief, this is the method I've used: dissolve the NaOH in a small amount off water, gradually add GBL, test ph, adjust ingredients as necessary, simmer to attempt to complete reaction. I have tried adding more NaOH to get rid of the excess GBL causing the smell but just end up with an overly basic solution. I have also tried simmering/boiling at length, but still cannot get rid of the smell without getting to the point where I am gonna burn the GHB.

I am aware that in order to crystallise the product the solution needs to be heated to 150c to be sure there is no water left. But the boiling point of GBL is quite a bit more than this (around 200c I believe) so I don't believe this will get rid of any unreacted lactone as has been stated elsewhere.

I have considered adding less GBL, and then lowering the ph with vinegar or another edible acid, howevver I have heard conflicting reports on what this does to the quality of the GHB.

I'd appreciate any advice... in particular I am looking for people who have had this same problem and worked out a way round this, as opposed to people just telling me to follow this or that recipe (which I have!), or that the process is so easy I must be stupid (I'm pretty sure I'm not... I have a PhD :-0)

Thanks!

PS - I'm using good quality GBL and food-grade NaOH

 

[cpuller]

Does this method involve keeping it at 100° C during the reaction?
How well do you calculate with mol numbers etc?
Do you take too much time shoveling the NaOH so that it maybe picks up too much water from the air? (making it heavier and therefore there is more lactone than NaOH)
Do you use ph strips to test the solution in the end?

I used some cheap method to do this conversion for small amounts and with the heat of the reaction only. Sometimes I made a better batch than other times. (Sometimes lactone smell sometimes tongue burn from too much NaOH in the end product)
I suppose keeping it at the right temperature would have helped and testing the solution witgh pH strips.

 

[brutus]

We don't allow synthesis discussion.

 

[sekio]

In the interest of safety:

Use an excess of base to destroy all the lactone, then after it's done hydrolysing, add vinegar or some other dilute acid (5-10% citric in water) with good mixing to bring it back to pH 6-8. The acid won't hurt the GHB; and drinking solutions at high pH (basic - lye water solutions) is highly inadvisable.