L-Ephedrine synthesis from L-phenylacetylcarbinol (L-PAC)

[rampage]

my first trial run of making l-pac, here is my recipe not sure if it's all correct but i'll give it a go anyway.

2.5 ltrs of h2o
87.50 gms of molasses
yeast and nutrient
20ml of benzaldehyde
75ml of ether

in to a 5ltr demijohn goes 2.5ltrs of h2o and 87.50 gms of molasses,
saturate wash with pure oxygen,
add yeast and nutrient and allow to ferment for 8hrs or so,
once wash is rapidly fermenting add 10ml of benzaldehyde ,
after 4hrs or so add another 10ml of benzaldehyde and allow to ferment for another 12hrs or more,
once finished remove yeast,
extract l-pac with 50ml of ether and then 25ml of ether,
combine ether and distill
collect l-pac?
theoretical yield 10ml is 50% conversion.

feedback is appreciated and i'll post my results once done.

 

[OrgUnikum]

It seems not to be understood that this is a condensation reaction of two aldehydes. Benzaldehyde and - what? So Acetaldehyde is added and there is your second one. Or Acetone in the Austrian Patent which Uncle Fester sold (it does not really work like most of his stuff). Or Pyruvate is added this is a energy source for the yeast and forms Acetaldehyde in the process.

So, if you do this without a second Aldehyde or a precursor of it then TWO Benzaldehyde will be needed as Benzaldehyde + Benzaldehyde works too but of course maximum yield counted from Benzaldehyde is reduced to half.

And Dextrose and Frucose can provide energy but no Aldehyde to the reaction.

 

[rampage]

hi ,which one would you recommend acetaldehyde or pyruvic acid?

 

[OrgUnikum]

Sodium Pyruvate is the gold standard. Calcium Pyruvate works too. Problem is you need a frigging lot of it so for serious production Acetaldehyde is better suited. If you can buy Paraldehyde - thats perfect, easily de-polymerized to Acetaldehyde and far better to handle.
With Acetaldehyde you need to add a energy source like sucrose or dextrose though.
The trick with pyruvate is that it does not need the yeast fermenting.

 

[rampage]

how much sodium pyruvate would be required?

 

[handle]

No point making l-pac. Yield 0.5ml l-pac per 1L of water. Makes No sense. 20L of water for 10ml of product? Mmm?

 

[rampage]

hi handle
may i ask how you worked that out?

 

[rampage]

do you have access to the full article?

 

[Consider]

But yeast fermentation method of ephedrine synthesis is said to be good yield for commercial production, how come 0.5ml for 1 liter of water, are saying true

 

[rampage]

thanks handle if that in fact is the case its not worth wasting chems

 

[OrgUnikum]

It is the main way l-PAC and ephedrine is manufactured industrially. 3 to 5 gram l-PAC per liter of reaction medium is realistically to get, more, well then it gets tedious. But for industry that is no issue, handling large volumes is no problem. Industrially Benzaldehyde and Acetaldehyde are ultra-low cost items, that is what counts. They just use a bigger vessel. T
he trick in the whole biosynth what nobody seems to realize is not fucking around with the reaction but use a bigger pot and keep it simple. And use continous extraction to retrieve the l-PAC - this way a small amount of solvent over a few hours pulls all the goodies from the big pot.
It is a mere technical problem except - well a source for paraldehyde or cheap pyruvate and most important: A strain of yeast which does the wanted conversion at a ph <5 . First: Not every starin of Cerevesiae does it all, few in good yields and even of those very few can do it at a ph <5 what necessary as above you mostly get the diol. Whats not useless but not what you want. And ideally you can buy this yeast as dry yeast in bulk for cheap. And no, I do not know of such a yeast to buy at the moment, I am again searching myself.

- yeast
- continuous extraction

ok?

 

[rampage]

interesting org, how would you go about doing a continuous extraction?

 

[OrgUnikum]

I would start using a bloody internet search engine

 

[handle]

Spoiler: Erowid link

Erowid link

 

[The-Hive]

I have a PDF on this but I like the way the conversation is going so I’m hold out uploading it…

 

[rampage]

sharings caring lol

 

[The-Hive]

G Grue-Sorensen - 1988

 

[OrgUnikum]

I have about 200 papers on the topic and I can assure you that most of them are useless and some intentionally misleading. In special Australian papers by Rogerss/Shin are of this kind.

 

[handle]

Some things people overlook when biosynthing L-pac from feeding benzaldehyde to yeast. You make the wort, with sugar, just like you are making beer or wine. After the yeast has grown and split enough, the benzaldehyde is added and reacts in a couple of hours and is ready to cyphon off for more work.
The yield seems like nothing when you consider the amount of affluent used. I figured it a few years ago and I think I calculated 20 grams from a 55 gallon drum every 4 days.. technically 3 days but you'd have to kick ass to centrifuge those 20 grams out of 55 gallons of rm

 

[OrgUnikum]

l-PAC threads are always instantly overrun by bullshitters, so I say good-bye.

You got the most important information: Acetaldehyde or Pyruvate, a suited yeast and ph <5.

Nobody asked the big and obvious question: How can I find out if a strain of yeast is good or not?
And as nobody asked, there will be no answer but the mention that rather easy methods exist.
Happy searching don't PM me.

bye

 

[handle]

How can I find out if a strain of yeast is good or not?

 

[The-Hive]

You can use a variety of bakers yeast/Saccharomyces cerevisiae

 

[handle]

Spoiler: Like this?

 

[The-Hive]

4 x 11g Fermipan Instant Yeast Ragi Saccharomyces Cerevisiae Baking Bread Bakery | eBay

Instant Yeast that is suitable for making bread. Last updated 07-Jun-2024 12:38:59.

www.ebay.co.uk

 

[handle]

I think try this fresh live yeast.

 

[The-Hive]

Do several small batches see witch ones best