Cou's esters megathread

Liquid in beaker on right is distilled isopentyl propionate.
Boiling point matches CRC literature value of 160 C

It smells similar to isopentyl acetate, but smells like actual banana fruit instead of banana-flavored candy. it has the slight tart that cavendish bananas have.




[Edited on 9-6-2020 by Cou]

Are you going to try it with chiral ester?
I mean, using chiral alcohols.
That would be really interesting!

In another thread I gave you the recommendation to make chiral alcohols by the yeast reduction of ketones.
I can tell you, I made chiral alcohols by the reduction with yeast and celery, from phenyl-2-propanone, resulting in both enantiomers, and they smell really different... and even more surprising, the sum of both, the racemic alcohol made with NaBH4, also smells different to each of the chiral ones.
I haven't tried mixing both together though, too valuable

A good compound to try this out with would be acetophenone I would say, or propiophenone, which are easily made or cheaply and then can be esterified as usual.
Maybe that would be a cool addition to your experiments?

Quote: Originally posted by Cou

www.consolidated-chemical.com is a good source for many alcohols and a few carboxylic acids, they ship to individuals. Many can be found on amazon, if not on their webpage. [Edited on 9-6-2020 by Cou]

Quote: Originally posted by karlos³

Are you going to try it with chiral ester? I mean, using chiral alcohols. That would be really interesting! In another thread I gave you the recommendation to make chiral alcohols by the yeast reduction of ketones. I can tell you, I made chiral alcohols by the reduction with yeast and celery, from phenyl-2-propanone, resulting in both enantiomers, and they smell really different... and even more surprising, the sum of both, the racemic alcohol made with NaBH4, also smells different to each of the chiral ones. I haven't tried mixing both together though, too valuable A good compound to try this out with would be acetophenone I would say, or propiophenone, which are easily made or cheaply and then can be esterified as usual. Maybe that would be a cool addition to your experiments?

Quote: Originally posted by karlos³

Well no, you can only get the (S) enantiomer with yeast. For the (R) enantiomer you have to use something else. But options are plenty, cheap and easy to get, just not so nice to work with since you use like 100g of (plant) material for 1g of substrate. As said, I used celery root for example. Here is the thread in which I posted some papers describing that route: http://www.sciencemadness.org/talk/viewthread.php?tid=154179 One of them has a table in which several of those biocatalysts are listed, together with the respective part of the plant and the resulting enantiomer. Onions are, if I remember correctly, another biocatalyst resulting in (R)-alcohols for example.

Motivation here

https://jameskennedymonash.files.wordpress.com/2013/12/table...




[Edited on 10-6-2020 by j_sum1]

Quote: Originally posted by Cou

I have that poster on the wall The image is way too big. Resize it to 25% on mspaint and post new imgur link

Due to the size of the image, this is truly a megathread

Octyl butyrate boils at 239 C
Not a very interesting one. it has a very faint slightly sweet waxy smell. might be contaminated with trace amounts of butyric acid, really hard to remove since it taints all distillation equipment. it makes me think of the color hot pink.

I am about to send my first package of esters to an SM user. I am happy to send 1 mL samples of esters to anyone who wants to smell them. $4 starting price and an additional $0.50 for each additional ester.

[Edited on 13-6-2020 by Cou]

[Edited on 13-6-2020 by Cou]

[Edited on 13-6-2020 by Cou]

Cou, it is really joyful to see you having found a niche, it is obvious you really found something which in turn gives you a lot back

I have found my own nichein hobby chemistry only a few years ago, and boy, that was a ride so far, and it never ends!
For me, it is the class of aminoketones, making them and making something in turn out of them, and over time it only gets larger and larger, and this is so cool
The fascination with them always sticked to me, and over time I realised the gigantic potential of being well accustomed with substances from this class, as so many belong to it, and I discovered additional ones of interest like, weekly.
While I make two of them, ten or twenty others pop up I never knew before, yada yada, and the whole thing exponentially grows
And I got really good at it, and while at it, my general chemistry skills also got much better, oh how it makes me happy to remember the day of my first aminoketone - a gamechanger and the begin of a joyful trip

Let me tell you one thing: at the point when you have accessed all the obvious and common target compoiunds, you might experience a little slowdown regarding finding new and interesting products, and that comes along with whatever you find being also harder to make.... I had that too when I made, maybe around 20 different and easily accessed products...
But don't let that affect you negatively!
This is the point where the real fun begins!
With increasing difficulty, they also increase the amount of fun and experience you gain, exponentially, and in turn a hugely growing confidence
From then on, it will get much better and really good

In maybe just three years people probably know whom to ask preferably for ester related stuff
I hope you will enjoy the ride and stick on that topic as long as it really gives you as much satisfaction as it obviously seems to do

Very nice! I'm also a big fan of Esters! I can really recommend making Methyl and Ethyl Cinnamate! I made them using the acid chloride via SOCl2

Quote: Originally posted by Tellurium

Very nice! I'm also a big fan of Esters! I can really recommend making Methyl and Ethyl Cinnamate! I made them using the acid chloride via SOCl2

Butyl salicylate:



faint floral blackberry smell

I only got 3 mL, a 24% yield. This was my first time making an ester of salicylic acid and an expensive alcohol, so there were some hiccups that I learned from.

When making methyl salicylate, you use a large excess of methanol as the solvent, because methanol is cheap and readily available [1]. but larger alcohols, such as 1-butanol, are specialty chemicals that should be conserved. salicylic acid is very cheap and readily available (I have a 1 kilogram bag from amazon that cost $35) so it should be used in excess to fully react all the 1-butanol.

Ideally benzene could be used for dean-stark technique, but benzene is expensive (for non-industrial sale), and carcinogenic.

I used a 3 molar excess of salicylic acid to 1-butanol. Xylene was used as the solvent (no dean-stark trap, just reflux). I added too much xylene than what was needed to dissolve all the salicylic acid. One day maybe I'll determine the solubility of salicylic acid in boiling xylene, but you could add a little xylene, heat to boiling, then drip it in with an addition funnel until everything is dissolved. Salicylic acid is much more soluble in boiling xylene than room temp xylene. Less is better

After refluxing for several hours, then allowing to cool, you should gravity filter to remove the unreacted salicylic acid, and wash funnel w/ xylene. Then proceed to typical fischer esterification workup: water, sodium carbonate, water. A simple distillation removes xylene first, then the salicylate ester comes out much later (this one boiled at 271 C)

[1] https://www.youtube.com/watch?v=lJLP2bcXDqY

EDIT: I found that salicylic acid is actually more expensive per mole than 1-butanol. It might be better to just use 1-butanol as the solvent. Ideally you should use benzene as the solvent and use the dean-stark technique, but I'm not sure if I want to mess around with benzene. Once you get to making salicylate esters of high boiling alcohols, such as 1-pentanol, toluene works as a dean-stark solvent. 1-butanol and 1-propanol are relatively inexpensive, so you can invest in larger amounts of those to use as excess solvents. I have a huge amount of salicylic acid so I chose to use it in excess with xylene solvent.

[Edited on 6-28-2020 by Cou]

Need help removing water from a small scale (0.06 mole) fischer esterification reaction. anhydrous magnesium sulfate?

it doesn't work with toluene b/c 1-pentanol and water form an azeotrope that screws up separation of water in the trap.

the volume of the reaction mixture is 16 mL

It's too small for a dean-stark apparatus if i don't use a solvent like toluene.

Molecular sieves are not compatible with fischer esterifications.

Can I use anhydrous magnesium sulfate powder to drive fischer esterification to products side?


EDIT
i found that i can use a pressure equalizing addition funnel as a substitute for a soxhlet extractor if i don't have enough volume

[Edited on 7-6-2020 by Cou]

Quote: Originally posted by Cou

Need help removing water from a small scale (0.06 mole) fischer esterification reaction. anhydrous magnesium sulfate? it doesn't work with toluene b/c 1-pentanol and water form an azeotrope that screws up separation of water in the trap. [Edited on 7-6-2020 by Cou]