Sciencemadness Discussion Board

Butyl acetate -> THF, at all possible/feasible/practical?

tandpasta - 30-6-2016 at 14:15

I found out that the leftover can of paint stripper I have laying around contains butyl acetate. Of course the first question is if isolation of it is possible (the product is a thick gel). If so, does the following synthesis route make sense?

Butyl acetate -> n-butanol (through carbonyl reduction with for example lithium aluminium hydride?)
n-butanol -> 1,4-(?)butanediol (oxidation?)
1,4-butanediol - tetrahydrofuran (dehydration under high temperature with phosphoric acid)

I got the last step from Wikipedia, which says: "In the presence of phosphoric acid and high temperature, it [1,4-butanediol] dehydrates to the important solvent tetrahydrofuran."

The reference given is:

Karas., L.; Piel, W. J., "Ethers", Kirk-Othmer Encyclopedia of Chemical Technology, New York: John Wiley, ISBN 9780471238966

which in turn cites
Japar, Steven M., et al. "Ozone-forming potential of a series of oxygenated organic compounds." Environmental science & technology 25.3 (1991): 415-420.

which I don't understand at all and I don't see why it was cited.

I'm missing really rudimentary chem knowledge, so sorry if this is a really stupid question. I'm not looking for the shortest route to make THF. I was hoping I could learn a lot by researching how to do this (if it's at all possible) and hopefully end up with something useful.

Metacelsus - 30-6-2016 at 15:13

1) You wouldn't need to reduce the butyl acetate if you wanted n-butanol; you'd just need to hydrolyze it.
2) Selective oxidation of n-butanol to 1,4-butanediol is probably not going to work. If you tried oxidizing it, you'd end up with butyraldehyde or butyric acid.
3) This seems doable; in fact, it's basically how THF is produced industrially (although they use different acid catalysts.)


PHILOU Zrealone - 30-6-2016 at 15:13

Possible! But long and difficult.

Butyl acetate + NaOH -water-> Butanol + Na acetate
Butanol + NaNO2 + HCl -water-> Butanol nitrite ester + NaCl
Butanol nitrite -photolysis-> O=N-CH2-CH2-CH2-CH2-OH <==> HO-N=CH-CH2-CH2-CH2-OH
The final oxyme is hydrolysed with diluted HCl acid to provide 4-hydroxy-butanal and hydroxylamonium chloride.
Reduce the aldehyde into 1,4-butandiol and heat with H3PO4...

Better dehydrate/heat erythritol to furane and then hydrogenate to THF.

CuReUS - 1-7-2016 at 07:56

I remember reading in March's Advanced Organic chemistry that n-butanol can be cyclised to THF using lead tetracetate.
https://books.google.co.in/books?id=4zrovKbIxOIC&pg=PA70...

[Edited on 2-7-2016 by CuReUS]

Praxichys - 1-7-2016 at 08:41

I think the 1,4-butanediol method is a great laboratory approach. Unfortunately it is also a controlled substance in the USA because it is a prodrug to GHB.

tandpasta - 2-7-2016 at 02:29

Would you guys consider this doable for a rank beginner? The steps that PH Z gave look quite doable, based on the preliminary research I've done. As in it can be done with standard glassware, cheap reagents and some sunlight, with no exceptional safety hazards.

I'm prepared to put in the research and preperation, but if there's a high probability that I'll fail, I'd rather expend my resources elsewhere. I know that you can also learn from failure, but I'd rather not have this big of a failure this early in my chemistry quest.

btw, I checked, and where I live, 1,4-butanediol doesn't seem to be on any list of illegal substances.

unionised - 2-7-2016 at 03:35

Quote: Originally posted by tandpasta  
Would you guys consider this doable for a rank beginner?


No.
Sorry.

myristicinaldehyde - 2-7-2016 at 05:35

See first if you can isolate it from the gel! When extracting painkillers, if a gel formed it's impossible to extract ANYTHING! Although to be fair it's a different kind of gel, I think.

How much butyl acetate is in the product?

Mabus - 3-7-2016 at 08:54

Here's the described procedure for anyone interested.
I would try it, but I lack the capability for making an anhydrous environment (PbAc4 is water-sensitive) and I only have rudimentary glassware.