Author Topic: benzaldehydes to phenylacetones  (Read 11690 times)

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  • Guest
« Reply #40 on: December 11, 2002, 11:02:00 AM »
aurelius presumes from the end product that the OH is in the alpha position, correct?  (nice procedure)  the brewer's wort, what is that?  can the reactants (bz. ald. and acetaldehyde) be added in one large portion with decent yeilds?


  • Guest
Orgy, To clarify a minor point, Swim is under the ...
« Reply #41 on: December 11, 2002, 11:34:00 AM »
To clarify a minor point, Swim is under the assumption that the brewers wort in question is simply a liquid barley malt, most likely canned, to which no additional h2o is added, is that the case?
 Organikum knows best, but swim believes from reading on the subject, adding the benzaldehyde etc. in a lump may poison the yeast and retard (or worse) the reaction in progress.

Iä-R'lyeh! Cthulhu fhtagn! Iä Iä!


  • Guest
patent and brewers wort
« Reply #42 on: December 11, 2002, 05:38:00 PM »
The patent

Patent US3338796

shows the possibility of using the described procedure on substituted benzaldehydes. Also an alternative fermentation medium is disclosed and a easy way for finding the right strain of yeast.

The synthesis described by me before is the best yielding known (the yields I got first time don´t count). Only if extracted and purified enzymes are used higher yields are propagated - up to 99%.

The "brewers wort" is here the wort as prepared for brewing a lager beer up to the point where the hops would be added. No hops and more important no boiling. The temperature of the malt (and wort) must never exceed 78°C. Or your coenzymes are gone. And for providing these coenzymes on a natural and cheap way the wort is used. Concentration of the wort should be this that it contains about 18% fermentable saccharose. A look for beer brewing answers most technical questions on fermentation, aeration, saccharose concentration, sterilisation.......
The used molasses should be made from sugar beets and contain about 50% sugar.


now or never


  • Guest
Very Very Nice!
« Reply #43 on: December 12, 2002, 05:40:00 AM »
This process is very amenable to being run in a "Bioreactor" (which is what the big Drug Companies do) and having the whole process automated. These bioreactors are composed of Glass Fermentation vessels, 1 liter and up. There is a top mounted motor for stirring, heating/cooling coils, and plastic feed lines for Air/Oxygen, and pH Up/Down, etc. Most have internal Oxygen and pH Sensors running to a computer control unit. You enter the parameters you want your fermentation batch to run at (i.e. temperature, pH, O2 levels, time to add other materials, etc) and the computer monitors and tweaks the "run". You can automatically add additonal materials (like benzaldehydes) at whatever rate and time you desire from bottles connected to peristalic pumps in the bioreactor. Most colleges with "Biotechnology" courses have one or more of these bioreactors. Older models turn up at auctions sites too.


  • Guest
fermenter and bioreactor
« Reply #44 on: December 12, 2002, 07:53:00 AM »
A internet connection for the bioreactor is a "must have" yes?  ;D
It´s like a brewery. Modern mass production high tech breweries vs. old style small ones. What beer tastes better?

Process control by sensors and computers or you have to look yourself thats the difference - a bucket with lid or if you want to go big a vessel for wine making are sufficient for the engaged amateur. Stirrer is a paint stirrer attached to the drill and aeration by an big aquarium pump or a small compressor (oilless one, no fridge compressor).
I advice everybody to do a lot of testruns without substrate, with only the yeast.

I am a tekkie myself but its not necessary and brings no better results. Sorry, this is 3rd world technology, this is ghetto. Whereby ghetto isn´t the right word - this is Missisippi?  ;)


now or never


  • Guest
What I was Trying To Say Is...
« Reply #45 on: December 12, 2002, 08:23:00 PM »
Yup, one can dump everything in a H2O 5 gallon glass jug and get it to work, BUT.... used technology is "cheap" and can make for tighter, better tweaking of fermentation params.
Ghetto here, thanks to the Internet, can mean finding what was a $20K technology at one time, for pennies on the dollar.
You'd be surprised what shows up on ZBay and college "garage sales", and used equipment sites.  That Pentium computer one can buy for $50 is more powerful than a mainframe 20 years ago.
Technology rules! The War Is Over!


  • Guest
and thus to me....
« Reply #46 on: December 13, 2002, 12:50:00 AM »
Oh oh, this to me for I get beaten all time for being tekkie.

No, of course it´s possible to get these parts quite cheap, but most would have to learn to operate them first...
A bucket is easier - no manual needed. If you go and invest some money, so do it for a glucometer, a oxymeter and a good ph control device which adds the phosphoric acid and holds the ph at a certain level.

The process has overall a very high tolerance wherein yields vary only slightly. You have to fuck it realy up before yields suffer badly. But for to be true: As long as I can buy toluene and EtOH by the tanker I don´t mind 10% up or 10% down. Byproduct is benzylalcohol which is easily converted to benzaldehyde again - nearly no loss, just a bigger bucket.
And a perforator for the extraction - who wants to boil 50 liters water away?


now or never


  • Guest
You have a point about the bucket being simpler, ...
« Reply #47 on: December 15, 2002, 03:14:00 PM »
You have a point about the bucket being simpler, if you factor in either the knowhow needed to use the hybrid mechanical/electrical/pheumatic/electronic devices of the past(including maintinence). 

And a bucket would sure be simpler than the design and development work needed to build a homegrown automation system using modern sensors and process control compononents.

But consider one other option...

What if opensource software were available that could do the following with cheep and readily available components

Component:    X10 dimmer (<$20)
Uses:       * Adjust current to heater coils for temp control
            * Adjust speed of DC stirrers,pumps and fans indirectly
              thru a linear AC/DC supply (most wall warts)
Interface:   Shareware ActiveX control & X10 rs232 interface $25

Component:   Cuecat (nearly free) or broken optical mouse
Uses:        rotation counters for spinner flow control
Interface:   rs232 or USB

Component:   Cheep Web Cam ($20)
Uses:        Read a cheep automotive vacuume gage
             watch sesitized paper for the presence of H2S or
             other toxic substances
Interface:   USB & thresholding/position mapping BMP's dropped
             out of an activeX

Component:   Sound card - A/D thru a single chip Vol to Freq convter
Uses:        Ph, temp, O2, conductivity using cheep probes off the

Component:   R/C servo's - ($10)
Uses         Attached to small valves for dripper control, flow control
             purge or relief falves

No circuites would have to be built by the user, any one of ten garage type companies will whip out and sell about any circuite you can describe without
case or powersupply for under $20, no questions asked.

The key is some clever opensource software, with a set of core routines to provide some base functionality aod structure with some LCD compatable HTML UI.  The interface and higher level logic could be simplified by the core providing a rule firing shell that executes VBScript rules.  To further simplfy the most basic customization, the core would automatically store parameters and history for the rules scripts, allowing any parameter to be profiles or externally controled by non-coders.

The bottol line...

A user could download a recipee/script off of the internet and succeed with
reactoins that they didn't even begin to understand the details of.  They would
just keep the feeder bottle from going dry, and the power on.  And assembly of the components would not necessarily be more complicated than plugging together a component sterao, once the sofware had matured a little bit and found a few good neighbors in the 3rd party hardware crowd.

That would make a bucket, and all the understanding and skills necessary to determine reaction conditions and proper responses and adjustments seem quite complicated in comparison.

And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!


  • Guest
more easy
« Reply #48 on: December 15, 2002, 09:14:00 PM »

The construction plans for a simple matter converter would solve most problems...


now or never


  • Guest
DEA would deam that an illegally usefull device, ...
« Reply #49 on: December 17, 2002, 07:12:00 AM »
DEA would deam that an illegally usefull device, emergecy schedule it with a retroactive death penalty for the inventors. Confiscate them all and use them to produce bullshit in an ever increasing quantity.


And on the eight day, God created Meth...
... and hasn't done much of anything usefull since!


  • Guest
Rhodium Archive Impact Factor
« Reply #50 on: December 25, 2002, 10:24:00 PM »
Speaking of Darzen, the name reaction database below (the most comprehensive I have seen to date) links to my page under the heading "Recent Academic References" - nice to see that my page carries at least some weight to professional chemists around the world  ;D


  • Guest
Hey Rhodium
« Reply #51 on: December 26, 2002, 10:00:00 AM »
That's not the only Reaction your page shows up on as a reference.  aurelius thinks that the author of that page might be a Bee ;D   that was part of the reason that aurelius decides to post the link for it.


  • Guest
Darzens article
« Reply #52 on: March 26, 2003, 05:40:00 AM »
Here some "historic background":

G Darzens. Condensation glycidique des aldehydes avec l'ether alfa-chloropropionique. C R Hebd Seances Acad Sci 142 (1906) 214-215.

Since we were able to set up a general method for the preparation of alfa,beta-substituted glycidic ethers by condensation of a ketone with alfa-chloropropionic ether 1, it was important for our work to evaluate if the same method would be applicable on aldehydes.
The condensation of chloroacetic acid homologues with aldehydes is much less general then the condensation with ketones. However, it is very remarkable that this reaction works while the same reaction with monochloroacetic ether fails miserably.
I was able to synthesize alfa,beta-disubstituted glycidic ethers by condensing acetaldehyde, propylic aldehyde and isovaleric aldehyde, but the yields were always very poor (never higher than 20-30%).
Saponification of these ethers yields rather stable acids; decomposition by heating was a most complex thing and I was unable to obtain ketones this way.
Trioxymethylene condenses swiftly and yields alfa-methylglycidic ether, also prepared by Melikoff.
However, in sharp contrast with these results is the high yield one can get with aromatic aldehydes. The obtained glycidic acids are easily decomposed, setting free a ketone of type R-CH2-CO-CH3.
- Benzaldehyde: gives a yield of 50% of the alfa-methyl-beta-phenylglycidic ether. Liquid boiling at 153-154° at 18 mmHg. The free acid is decomposed by vacuum distillation, setting free methylbenzylketone (characterization by its semicarbazone).
- Anisaldehyde: yields alfa-methyl-beta-anisylglycidic ether, boiling at 189-190° at 20 mmHg. Its Na salt decomposes by simply boiling its solution in Na2CO3. The resulting PMP2P is characterized by its semicarbazone and its oxime.
- Piperonal: gives a glycidic ether which biils at 205-210°C at 25 mmHg. MDP2P can be obtained in a similar way as PMP2P by boiling the Na salt.
- Furfurol: its aromatic aldehyde analogues are known, and I  was able to prepare ethyl alfa-methyl-beta-furfurylglycidate  easily, obtaining yields of 50%. The colourless liquid boiled at 150-151°C at 30 mmHg. This glycidic ether is easily saponified by NaOH solution and boiling the solution several minutes is sufficient to obtain the furfurylacetone. This ketone, formerly unknown, is a colourless liquid boiling at 179-180°C. Its semicarbazone melts at 173-174°C, its oxime is a liquid and can be distilled at 135-140°C (25 mmHg). [...]

The original text is available at Gallica.


  • Guest
What do ya know, nobody used TFSE ;-) Post...
« Reply #53 on: March 31, 2003, 02:49:00 PM »
What do ya know, nobody used TFSE   ;)

Post 285765

(foxy2: "Piperonal to MDP2P", Novel Discourse)

That thread has a patent ref for Bariums Procedure, 2-Chloropropionic acid methyl ester synthesis ref and 2-Chloropropionic acid synthesis refs.  It goes quite nicely with this thread.


  • Guest
post No 379632
« Reply #54 on: April 03, 2003, 03:47:00 PM »
Add the toluene, benzaldehyde and haloester to a rb flask equipped with a mag stirbar, thermometer and a addition funnel. With cooling, add the sodium methoxide solution dropwise at a rate which keeps the reaction temperature between 10 to 15°C. When the addition is over allow the mixture to stir at room temp for one hour.
The toluene solution of the glycidic ester is now poured into 1 mol NaOH, as a 5% aqueous solution, and the mixture heated to 70-75°C for 60 minutes to hydrolyze the glycidic ester. The toluene layer is then separated from the aqueous layer. The sodium salt of the glycidic acid can now be isolated by concentration of the aqueous solution to about one third of the original volume and cooling to 10°C, filtration and washing with cold MeOH affords the salt in a quite pure form.

Now does Barium mean that he hydrolyze the entire solution? Or does he seprate the toluene first then hydrolyze, only the toluene?


  • Guest
Barium does indeed mean that the toluene ...
« Reply #55 on: April 04, 2003, 01:23:00 AM »
Barium does indeed mean that the toluene solution is combined with the NaOH solution and the two solutions are heated for one hour under constant stirring. The ester which was made in toluene is now hydrolyzed and becomes a sodium salt wich is not soluble in toluene anymore, but it is soluble in water. Thus, the crap stays in the toluene and the product moves to the water phase.


  • Guest
ok, i got it
« Reply #56 on: April 04, 2003, 09:44:00 AM »
sometimes, it takes a few readings to get things together, for some reason i was thinking that there was a aq layer along with the toluene, but i see the error of my ways. Thanks Barium


  • Guest
acid catalyzed Darzen ?
« Reply #57 on: October 05, 2003, 01:00:00 PM »

mentions that the Darzen reaction can also be catalysed by an acid, does anyone know anything about that ?

Also, while I'm in asking-mode: would it make any difference, which PTC is used, i.e. could TBAB substitute for Aliquat 336 ?



  • Guest
methyl 2-chloropropionate
« Reply #58 on: October 05, 2003, 01:50:00 PM »
A rather large scale synthesis of this precursor can bee found in

Patent US4334083


  • Guest
Methyl 2-Chloropropionate from Methyl Lactate
« Reply #59 on: October 05, 2003, 04:18:00 PM »

Patent US4334083

, Example 1:

A round-bottomed flask is used which is equipped with a stirrer, a Vigreaux-type condenser, a thermometer, a dropping funnel and liquid nitrogen traps arranged downstream of the condenser.

Methyl lactate (832 g, 8 mols), [a]D20 = +7.48° (without a solvent), is placed in the dropping funnel and thionyl chloride (1060 g, 8.9 mols) and pyridine (4.15 g, i.e. 0.49% by weight of the amount of methyl lactate to be converted) are placed in the flask.

The methyl lactate contains about 1.03% of ethyl lactate as an impurity and 0.61% of other impurities including methyl lactyl-lactate.

The temperature of the flask is raised to 60°C, whilst stirring, and the methyl lactate is run in over a period of 4 hours, whilst keeping this temperature constant. When the introduction is complete, the temperature is raised to 75°C. and this temperature is maintained for 1 hour. Analysis by gas phase chromatography, carried out at this moment, shows that there is no more methyl lactate in the reaction mixture. Heating is continued for 20 minutes and the mixture is then left to cool for 20 minutes, under a partial vacuum of about 150 mmHg, to a temperature of about 40-45°C.

A crude product (992.5g 884 ml), comprising crude methyl 2-chloropropionate, SO2 (19.2 g), SOCl2 (1.6g) and HCl (1.8 g), is obtained.

Analysis, by gas phase chromatography, of the crude methyl 2-chloropropionate thus obtained gives the following composition by weight (excluding SO2, SOCl2, HCl and pyridine):

97.7% - Methyl 2-chloropropionate   
1.22% - Ethyl chloropropionate   
0.04% - Methyl acetyl-lactate   
0.08% - Methyl acetyl-lactyl-lactate
0.67% - Chloropropionate of methyl lactate
0.01% - Chloropropionate of ethyl lactate
0.03% - Lactide (cyclised methyl lactate)
0.11% - Chloropropionate of methyl lactyl-lactate
0.14% - Unidentified impurities

The formation of ethyl chloropropionate, methyl acetyl-lactate and methyl acetyl-lactyl-lactate results from the impurities present in the starting methyl lactate (yield of methyl 2-chloropropionate: 98%).

The crude product obtained above (900 g) is distilled, under a pressure of 20 mmHg, in a 40 cm high packed column. When distillation is complete, the vacuum is increased to 3 mm Hg. At the outlet of the packed column, the uncondensed vapours pass into a liquid nitrogen trap.

Distillation makes it possible to obtain the following three fractions:

Methyl 2-chloropropionate (95 g) of optical rotation [a]D20 = -25.37° (without a solvent)
Methyl 2-chloropropionate (675 g) of optical rotation [a]D20 = -25.26° (without a solvent)
Methyl 2-chloropropionate (71 g) of optical rotation [a]D20 = -24.56° (without a solvent)

At the bottom of the column, a residue (13 g) consisting of heavy products is recovered. In the liquid nitrogen trap, methyl 2-chloropropionate (17 g) containing traces of HCl, SO2 and SOCl2 is recovered.

After distillation, and taking account of the 2-chloropropionate recovered in the nitrogen trap, the yield is 97.2%.