MichaelBijanAfghani
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[Video] Making tert-amyl acetate. grape aroma
Video: https://youtu.be/3wA__rOdcF8
I have lots of experience with Fischer esterification, but tertiary alcohol esters have not been explored much. The Internet and literature seem to be
devoid of odor info for any tertiary alcohol ester greater than tert-butyl acetate (said to have a blueberry or camphor kind of smell). So I've always
been curious about tert-amyl acetate.
Tert-amyl alcohol and diethyl ether were dried over molecular sieves overnight. The reaction flask was flame dried. Tert-amyl alcohol (18.4 mL / 0.172
mol), N,N-dimethylaniline (26.5 mL / 0.209 mol) and 25 mL diethyl ether were added to the flask. The flask was fitted with a graham reflux condenser
with circulating ice-cold water, and an addition funnel. The mixture was heated to reflux. Acetyl chloride was added to the addition funnel. I meant
to add (14.1 mL / 0.198 mol) but made a mistake with the addition funnel and lost some down the sides, so I added an unknown excess (around 20 mL I
estimate) which is okay because it will be neutralized in workup. All the acetyl chloride was added over 1 minute, and addition caused bubbling of
white HCl mist. The mixture was refluxed for 1 hour.
N,N-dimethylaniline hydrochloride white precipitate
After cooling to RT, there was white N,N-dimethylaniline hydrochloride precipitate at the bottom of the flask. 25 mL of water was added to dissolve
it. The ether layer was extracted twice w/ ice cold 10% H2SO4 until the drained aqeuous layer no longer formed white precipitate on addition of NaOH
solution. then washed twice w/ sat. sodium bicarbonate until no more CO2 formation, then dried w/ anhydrous sodium sulfate for 5 hours. Simple
distillation removed the diethyl ether first, then tert-amyl acetate distilled over at 125 °C.
Smells like grape candy.
Send me a U2U if you would like to request a small sample in the mail to smell it for yourself
Michael Bijan Afghani
[Edited on 24-11-2021 by MichaelBijanAfghani]
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Fery
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Hi Michael, well done!!! Very interesting reaction and ester !!! Especially the difficulty with a reactant alcohol prone to elimination thus hard to
esterify.
Databases lack info about its scent, only few parameters reported (gravity, boiling point...)
http://www.thegoodscentscompany.com/data/rw1459651.html
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MichaelBijanAfghani
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I just noticed that Pubchem said it smells like bananas, and I can see (or smell) why it would say that, now that it mentioned it. I'd say it smells
halfway between banana and grape.
The boiling point on good scents is completely wrong. 256 to 256 °C? Scifinder literature says 125 °C and I confirmed that.
Michael Bijan Afghani
[Edited on 24-11-2021 by MichaelBijanAfghani]
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Fery
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Hi Michael, yes b.p. of acetates does not differ from b.p. of corresponding alcohols too much.
b.p. of tert-butyl acetate is 82 C so I believe your boiling point, not the b.p. in the link.
So in you reaction the tertiary amine is used to capture HCl and ether for keeping reaction mixture at 40 C.
I tried to scent some esters which scents I was unable to identify by myself, only after reading information I realized yes that's true what is
written. Sometimes I found that the written information was not correct, but that was maybe only my genetical variability?
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Dr.Bob
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Great job. I know that isoamyl acetate smells like bananas for sure, made that years ago, but have never smelled tert-amyl acetate, so that is neat.
You could make a great smelling lab\, much better than alkyl isonitriles...
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Bedlasky
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Hi. I read about mangese(III) acetate catalysed synthesis of alkyl acetates with 99% efficiency (even in the case of reaction with tertiary alcohol).
https://sci-hub.st/https://www.sciencedirect.com/science/art...
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DraconicAcid
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That is an amazing paper, if it works. Does someone have a copy of the reference for the preparation of manganese(III) acetate?
E.I. Heiba, R.M. Dessau, W.J. Kolhl Jr., J. Am. Chem. Soc. 91
(1969) 138–145.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Bedlasky
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Look at this:
https://www.designer-drug.com/pte/12.162.180.114/dcd/chemist...
I also saw video from Chem Player on this synthesis.
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