P2P [Phenylacetone] via aldol & Baeyer/Villiger

Guest · Tue Feb 22, 2005 3:03 pm

That's great work,
~18g doesn't sound too bad, considering your just getting the hang of it,

Tremendous work,

I don't as yet fully understand all the mechanics of the various Aldol reactions, mixed, acid catalysed, basic, etc,
But somewhere I do remember a post replacing The dry Hcl,
with another acid,
Sulphamic, or something,. oh well,

Astrum,
You are welcome to do a full write up, with any media, if you have it.

Good to see this method, getting the attention it deserves,.

Benzaldehyde is readily made in many.many different ways,
This is a great route for PMK(p2p)

syn

bio · Working Bee

Twodogs the person that introduced this method to the Hive some years ago said in the original thread that he tried aqueous sulfuric acid and also concentrated HCl acid but did not get the results he did with the HCl gas. There was no further elaboration on the difference in yields.

This is most likely due to adding water to the reaction which has an equimolar amount of water produced along with the condensation product. This would drive the equilibrium in the wrong direction. Some aldols are quite sensitive to water contamination and require standard precautions such as drying tube etc. This reaction does not seem very sensitive to small amounts of water and no particular precautions are needed. An inert dessicant might work to improve yields if using aqueous acid but it hardly seems worth the effort HCl gas being so easy to make. One person who had very good sucess told me that he didn;t even dry his gas and his results were on par with the best.

Some of the original aldol type condensations (knoevenagle for example) used a very small amount of catalyst and let the mix sit for a couple of weeks in the dark at ambient temperature. This might work with concentrated H2SO4 using only a few drops or one of the newer solid super acids.

IndoleAmine · Dreamreader Deluxe

Most of the old aldol condensations need either a water-miscible solvent (like alcohols), a dessicant like silica/mol.sieves, and/or some way of mechanical water removal (dean-stark trap) to work properly and to give good results (Knoevenagel for example). Embarassed

When gassing with HCl, the two important factors are time and temperature. If the benzaldehyde/MEK mix isn't cold enough, more tar will be formed due to self-condensation of the starting materials. Same thing applies for going too fast during the gassing stage (gassing should take 4-5 hours MINIMUM), and (of course) over-gassing has the same polymerization effects..

I don't think that adding stronger acids directly to the rxn would solve this problem; although they can in fact "dehydrate" the reaction effectively (especially sufuric), they also can make great red tar quite quickly..

(SWIA once had a suck-back accident during gasssing, and the MEK/benzaldehyde was sucked into a H2SO4 bubbler. The reaction occured under heat evolution, and the result was much tar and little product. But then again, this was probably waaay to much H2SO4 and much too high of a reaction temperature...)

Oh, and last but not least: most acids (especially solid super-acids Wink

) cannot be distilled, so there is no option for recycling the molar excess of MEK - you have to wash with bicarb (or similar) to neutralize the acid pre distillation, and this removes the MEK too quite effectively. With HCl gas, the MEK can be recovered very easily before distilling the a,b-unsaturated ketone...

i_a

IndoleAmine · Dreamreader Deluxe

Did I mention that this was one of the most frustrating days SWIA had lately? Crying or Very sad

The peracetic B/V oxid. was allowed to run for 36h total, after this time no exotherm rxn could be detected anymore.

The acetic was distilled at 100 mmHg - almost 700ml recovered, but didn't solidify upon freezing. Not pure...

The remainder solidified upon cooling and was diluted with 300ml of hot water. This was extracted 3x with toluene (450ml total), the emulsions were dealt with by washing with copious amounts of hot, dilute brine and bicarb solutions.
The combined toluene extracts were dried over Na2SO4 and the solvent stripped to leave a nice yelow oil with a very fruity smell (definately ester, together with unreacted MePhBuO). The unreacted phenylbutenone was fractionated (at least most of it), came over at <130°C/aspirator vac.

Then SWIA decided to do something stupid - and dropped the receiver flask containing at least 70g unreacted, solidifed MePhBuO into a hot oil bath accidentally. The "nature-identical cherry aroma" was immense and overpowering, the oil bath was dumped, and SWIA had wasted lots of solvent, energy and time on recovering something which was lost now.
Evil or Very Mad

...

To the remaining slightly orange-colored oil was added 80ml EtOAc and 350ml 10% aequ.NaOH, and the whole thing was stirred at 80°C for 1,5h.
The color changed from orange to red/brown.

Then, the reflux condenser was replaced with a distillation setup, the mixture diluted with 120ml hot water and heated to a vigorous boil to steam distill the BMK. It came over as an almost colorless oil, with a slight tint of green to it, and the typical smell.

Steam distillation is still in progress, and the product will be recovered by extracting 2-3x with toluene, followed by drying the combined extracts and solvent removal at the rotovap at full aspirator vacuum (currently 6mmHg due to good weather and cold, cold 4°C tap water, in these winter daze Cool

)

I don't think the yield will approach 90% this time Laughing

, but we're working on that...
(will report back if I get to know the results)

i_a

Astrum · Wed Feb 23, 2005 8:52 am

SWIM pretty much followed bio's post (No: 472943) from the-hive. A few minor differences, for instance I used toluene for extraction instead of DCM.

This method really is easy, it just takes a lot of time to complete.

IndoleAmine · Dreamreader Deluxe

bio · Working Bee

.....................I think the reason is that he added 300ml hot water during workup, and tried to properly recover the unused MPB. The ester was partially hydrolyzed before separation of starting material and product was attempted, and the P2P was mostly removed with the unreacted MPB...............

I don't know how hot the water was or how long it was in contact but I do know that RT water is OK for the ester.

My hunch is that the hydrolysis conditions damaged the ketone by not using enough solvent and heating. With no heat added and the 50/50 EtOH mix with the given amount of NaOH causes about a 20deg rise and I always add it slowly and stop after about 2 hours. Apparently BMK is sensitive to too strong of base but what that is empirically I don't know. One run when the hydrolysis was run at 60deg returned about 20% less than usual but I couldn't completely attribute that only to the hydrolysis as some other variables had been introduced. It's important imho that only one condition at a time be varied to get some kind of meaningful experimental results.

Also using slightly stronger base with less solvent works OK. Although I have always stayed with the original molar proportions one bee did this with less NaOH with the same results. How much excess is required is hard to say.

IndoleAmine · Dreamreader Deluxe

IndoleAmine · Dreamreader Deluxe

bio · Working Bee

This is the excerpt from WD I promised. Only that which hasn't appeared in other threads is included and has only been edited as to form NOT content.

bio
Professor of P2P @ Ketone University

Just found this site today and am pleased to see so many bees here. I was running some experiments with a couple other bees and now have no way to reach them. If perhaps they read this please PM me. The catalyzed below 30deg oxidation (22-26deg) was a great success with a yield increase to 55% molar. Recycling is also working out well.

So many reactions........so little time

IndoleAmine
New Dreamer

AFOAF of mine will try this very soon, he feels that more experimenting has to be done as this is a really marvelous little procedure...

psuedonymph
WD Secretary of the Interior: Kung-Futon Master

Have any of you guys entertained the idea of adding a little TAED?

Astrum
Starting Dreamer

SWIM has been working with this method as of late. It's a decent method and it does work well enough.

bio
Professor of P2P @ Ketone University

Here is an excerpt from an interesting article I bumped into when doing a searcha year or so ago. Never tried to find the OTC stuff pure (TAED)

Another thing on the to do list. Anyone have an idea of an OTC source. Please don't say detergent!

152 JSDC VOLUME 115 MAY/JUNE 1999

If we go back some 30 years or more,consumers coped better than they donow. They probably owned a twin-tubwashing machine, had less colouredarticles and took more time to separatetheir wash loads into whites andcoloureds. Whites were washed at high
temperatures and the coloureds, usingthe same water, were washed at lowertemperatures. The oxygen bleach (perborateor percarbonate) was effective atthe high temperatures used for ‘whites’
and was relatively ineffective at the lowertemperatures used to wash coloureds(Figure 1)Times have changed; the growth in
the use of synthetic fibres and fibre blends, new applied textile finishes and the increase in coloured textiles means
that consumers have to wash at the lower temperatures of 40 and 50 °C.The first requirement for the wash isto remove stains and to achieve this atlow temperatures has meant the
development of low-temperature bleach activators. In Europe the activator is TAED, tetra-acetylethylenediamine,
while in the USA and some other countries SNOBS, sodium nonanoyloxybenzene sulphonate, is preferred.
TAED is a hydrophilic bleach that,under European wash conditions of lowliquor volumes and relatively long wash times, is effective in achieving stain removalat low wash temperatures (Figure
2). SNOBS on the other hand is a hydrophobicbleach that is effective under American wash conditions of high liquor
volumes and short wash times.Hydrogen peroxide is a weak bleach at
low temperatures, and the function of theactivator, TAED or SNOBS, is to react chemically with the peroxide in the wash
solution to produce a more activeFurther investigations have shown
that 30% of cotton articles fade noticeablyand irreversibly after repeated washing in a bleach-containing detergent’
bleaching agent, peracetic acid orpernonanoic acid and the diacylperoxide (DAP)(Scheme 1).Hydrogen peroxide and peracetic acidor pernonanoic acid are susceptible to wasteful decomposition in the wash. The most important side reaction is the
mutual decomposition of peroxide and peracetic acid or pernonanoic acid (Scheme 2). This reaction is catalysedby the presence of metal ions and can be inhibited by the inclusion in the
detergent formulation of phosphonate based ethylene diamine sequestrants Additionally, the reference detergent
used in these protocols is unrepresentative of market place detergents.The detergent industry workingthrough the Fastness Tests Committee of the Society has introduced a nonphosphate
reference detergent to which bleach activator (TAED) and sodium
perborate tetrahydrate can be added.This formulation in colour fastness testshas been shown to correlate well with
marketplace heavy-duty activated bleach-containing detergents and has been adopted by the European Colourfastness
Establishment (ECE).

The base formulation, TAED and sodium perborate are available through the Society.

IndoleAmine
New Dreamer

I recently dreamt that both sodium perborate*4H20 and TAED are available very cheaply (and by the kilo) through professional detergent suppliers...

IndoleAmine
New Dreamer

Psuedo: now that we have entertained ourselves with the idea of adding TAED to a peracid during the Bayer-Villiger
oxidation of MePhBuO: For which purpose would one WANT to do something like that?

Yes, perborate and TAED go well together for washing clothes - but this doesn't mean they're good for peracid
formation using NaH2BO4 and GAA, or did I miss something?

psuedonymph
WD Secretary of the Interior: Kung-Futon Master

quote:Originally posted by IndoleAmine

Psuedo: now that we have entertained ourselves with the idea of adding TAED to a peracid during the Bayer-Villiger
oxidation of MePhBuO: For which purpose would one WANT to do something like that?

Yes, perborate and TAED go well together for washing clothes - but this doesn't mean they're good for peracid
formation using NaH2BO4 and GAA, or did I miss something?

Perborates function best at 60 Celsius, and this reaction needs to be ran at 30 C or below due to the sensitivity of 2 - acetyl - propenylbenzene.

I noticed that cold water detergents utilise TAED to activate perborates below 60 Celsius, and was wondering if TAED would be beneficial for this purpose.

AS to whether this has a benefit to dreamers, I don't know.This is purely hypothetical, just thiinking out loud.

bio
Professor of P2P @ Ketone University

The part of the article which was the graphs I couldn't copy. Basically it shows that the TAED activates (by forming peracetic)
the perborate to function at 40-50deg whereas perborate alone needs around 90deg used alone to effectively bleach out stains. The graph shows that at 80deg the TAED marginally improves stain removal (85 versus 95%) but at 40deg it is twice as effective (60 versus 30%. This is simply because peracetic is a stronger oxidizer than H2O2.

I don't think you missed anything here, IndoleAmine, as in our case we WANT the peracetic to decompose or the reaction can't proceed.

The reason the perborate4H2O is "more effective"(really just faster) above 60deg is because it "dissolves" actually melts at 63deg per CRC (melts in water of hydration to form the tri if not in solution) and loses water at 130-150deg per CRC.

One reason I remain somewhat skeptical about the 30 deg reaction being the main answer to higher yields is because in the one runaway I had (prior to adding the perborate portionwise to the substrate) the temp went to 115deg and was starting to reflux when it pooped out with me frantically putting the hose on it (I'd had wet iced towels on it from about 60deg) praying the eruption didn't happen. Good thing had a reflux condensor on it . Anyway it was all over in 2 hours and was the best yield to date at that time. About 43% I think. So you see what I mean??? I'm skeptical. My opinion is the answer lies in a catalyst. And please forget the RheniumWhateverItIs that gave the 92% yield.

The article below confirms that it works from 20deg just takes longer and really doesn't dissolve at all. One bee told me he tossed the mix out because he thought his perborate was bad cause it didn't dissolve. Poor fucker tossed his goods.

This from Ullmans.......................

Physical Properties. Sodium perborate tetrahydrate, Mr 153.9, r 1.731 g/cm3, theoretical active oxygen content 10.38 wt %, melts in its own water of crystallization at 65.5 °C.
distribution of 0.1 - 1.0 mm. Depending on the crystal shape, bulk densities of 0.65 - 0.9 kg/L can be obtained.

When stored under cool, dry conditions the rate of loss of active oxygen is only 1 % per year. Decomposition is accelerated at higher temperatures and moisture content.

There is a tendency for increased caking at higher temperatures caused by conversion of the tetrahydrate to the trihydrate [39].

The solubility in water is 0.152 mol/L at 20 °C and 0.388 mol/L at 40 °C. 23g/l 60g/l

Thermogravimetric analysis curves for sodium perborate tetrahydrate show that decomposition takes place in three stages: 20 - 150 °C, 150 - 165 °C, and 165 - 400 °C. In the first stage, the tetrahydrate is dehydrated to the monohydrate.

[39] D. W. van Gelder, Recl. Trav. Chim. Pays-Bas 75 (1956) 117 - 126.
The commercial product is a white, crystalline solid with a spherolitic or elongated particle shape, and a particle size

....................................

sodium perborate hydrates are partially hydrolyzed, reforming the starting materials metaborate and hydrogen peroxide according to the following equation
t in aqueous solution the sodium perborate hydrates are partially hydrolyzed, reforming the starting materials metaborate and hydrogen peroxide according to the following equation [37]:

OVER

madchemist
Starting Dreamer

SWIM is lucky enough to have the materials/equipment involved and does have some experience with this method. Just recently found the thread and others a few months before The Hive went down. SWIM has a whole BMK compilation based on this route alone, SWIM can e-mail a zip file if any one wants (got no place to upload to, too lazy to register something right now).
It's got valuable Hive posts on this route + benzaldehyde manufacture, a few pics, some patents, some MSDS sheets, basically all the info one with the knowledge could ever want to safely and properly pull this synthetic pathway off with no problems at all, and then some.

SWIM spends 80% of most of his tweek-time using it as a tool to learn about O. Chem, and also study new potential OTC methods so he can tweek even more. Screw the good book, books like Vogel and Solomons are the real holy bibles! After all life is all a result of the shitloads of never-ending always changing chemical reactions down to the subatomic particle and the energies that apply.

Anyways (so many run-ons and tangents, so little time) this is a kick-ass route, but SWIM agrees yeilds in both the aldol condensation and the Baeyer-Villiger can definitely use some vast improvements.

Keep in mind that this is definitely not all there is as far as the sacred lost art of coupling the holy ring with various holy hydrocarbons to get good old sun-drop, rose-petal, kodak jack, prope dope or whatever your clique may have called it. Ever since SWIM
began studying all the types of coupling/condensation info he could gaze upon, so many doors leading to all sorts of kick-ass potentially OTC kitchen worthy routes for phenylacetone have come into play, and so much more are waiting to be discovered. After all, clandestined chem is all about being clever.
But thats for another thread! I'm already way off subject here.

Anyways, about the aldol condensation:

Cons for SWIM with the HCl cat. MEK/PhCHO:

Distilling:
SWIM doesn't know about every one else, but a lot of precursor is destroyed upon distillation. There is tarry like shit left (in the still flask) that is a bitch and a half to remove, indicating some degredation/yeild reduction.
SWIM does not currently have a vacuum source, although he does have required glass and equipment to not only build a continous aspirator, but also glass for fractionating under vacuum, complete with one of those valved manifold receiver things. You know so the vacuum doesn't have to be disturbed when switching recivers (SWIM has no cow dammit), never even been used. Right now his current living situation has put a lot of dreams on hold, and SWIM is reduced to simple lab procedures due to this situation (mainly on the factors of being detected).
He only breaks out the hand pumped auto-engine vac. line checker when he needs to use the buchner or just plain speed up filtration on the plain funnel/vac. filter flask.

So when SWIM distills the MePhButenone it's of course at normal pressures. As quoted in a lot of The Hive's threads pertaining to this, vacuum distilling will definitely raise yeilds to a worth-while degree. Plus it wouldn't be as hard to clean out the still flask hehe.

Catalysts:
SWIM always used dry HCl gas, but there was some mention from twodogs in some of his rantings that mention using H2SO4. He stated he got good yeilds by adding catalytic amount of H2SO4 to the mix and refluxing. Although that seems to me (harsher acid, higher temps) that it would actually form more by-products but hey it could work. SWIM may try this the next time he has the chance.

There is also several patents/refs from those old posts pertaining to other things being used as catalysts also. However, they usually used more complex compounds, the types which start bringing this out of the OTC way. Got to be OTC!! No suppliers that tightly record your business and may get you caught. No hassle of making fake docs/info or company or whatever (which sometimes can get you in as much trouble as drug manufacture itself), or anything. Gotta love OTC materials!

The reaction:

It works because the acid catalyzes enolation of the MEK, causing it's alpha carbon to react with the enolized benzaldehyde. This coupling is made a condensation by the acid also catalyzing dehydration of the newly formed enol to give MePhButenone.

Now all prior attempts were done just like the posts, and the benzaldehyde and MEK were just mixed together.

Now with using HCl gas, this may not be all that bad depending on how much gas the mix can hold. My book says at least for base catalyzed crossed aldols (and SWIM's assuming this for acid ones as well, but could be wrong) that compounds with no alpha-hydrogen (aka the benzaldehyde) do not self condense. So thats good. The MEK, however does have an alpha-carbon and will self condense in a crossed aldol. There is one possible yeild reducer, esp if one were to attempt this with sulfuric which would all be in contact with all reagents (instead of being slowly introduced like HCl gas) until the end.

The book then goes on to say that the non-alpha carbon (PhCHO) and catalyst are mixed first. Then the alpha-carbon containing reagent is to be slowly added, to effectively reduce side rxns. This means higher yeilds.

SWIM is definitely gonna try using H2SO4 next, by mixing PhCHO with it and dripping in the MEK. SWIM is undecided about heating or not but two-dogs did claim to reflux.

(After a quick reveiw, he stated that refluxing in conc. HCl acid, or H2SO4 worked, but not as well as dry HCl. He also states something about water that is formed as byproduct do not effect the condensation as much.)

That may be true, but it just seems highly unlikely that all the H2O from conc. HCl would not give very high yeilds.

Thats another suggestion for higher yeilds, maybe adding something inert like silica-gel or using Dean-Stark or something to separate the formed H2O when using reflux with H2SO4 would make that work a lot better.

With this method,

Now as for the Baeyer-Villiger, my views and thoughts and past experiences and shit will have to wait till later on tonight. SWIM really has to get going got shit to do today. Woke up at 10am did some ---- and now it's 4pm and SWIM is still sitting here trapped.

Before SWIM goes off for the day, he wants to mention another route from MePhButenone. SWIM hasn't tried it yet, but sees no reason why it shouldn't work as the rxns involved are well covered.

If the low yeilds of the Baeyer-Villiger is pissing you off, forget it entirely. If you look at the structure of methyl phenyl butenone, you begin to release it's an alpha-methyl type derivative, as well as a methyl-ketone derivative, off nothing any more special than cinnamic fucking acid! So what to do, how to convert to alpha-methcinnamic acid?

Well, right away SWIM sees the methyl-ketone group being converted back to the carboxylic acid (ex:p2p back to PAA) with a well known easy performed synthesis known as the haloform rxn.
Thats right, the same procedure using hypohalite salts (bleaching powder) to oxidise simple methyl ketones like acetone or MEK to get a haloform (CHCl3 with bleaching powder) and a carboxylic acid. Simply put, the methyl group swaps with an OH. Or R-(C=O)-CH3--->R-(C=O)-OH or better written as R-CO2H.

So basically running your basic haloform rxn on methyl phenyl butenone would give you some alpha-methylcinnamic acid.

Now if you do have access to things like Raney Nickel and sodium azide, then the procedure at Rhodiums using a-Me-cinnamic acid---(Raney/Ni)--> a-Me-hydrocinnamic acid. From there you can react it with the azide and H2SO4 via the Shcmidt rearangement to proceed directly to racemic amphetamine. You can always resolve if racemates aren't for you. Also one could form the N-formyl derivative and reduce that to get ----. Also as for resolution, a-Me-hydrocinnamic acid (reduced double bond) can be resolved to pure dextroratory isomer before the rearangment. The result is pure dextroamph.

******A side note about crossed aldol's:
SWIM just noticed in that Rhodium doc mentioned above [Optically Pure Amphetamines by way of alpha-Methylcinnamic acid], they have a clever little crossed aldol to form a-Me-cinn. acid directly.

Condensation of benzaldehyde with methyl proprionate gives alpha-methylcinnamic acid. MEK can be treated in that usefull haloform reaction to give propionic acid. Esterfy in the usuall mannor with methanol to give methyl propionate.
They do it by adding NaH to methyl propionate and adding ethanol as a catalyst. This forms some type of alkoxide base perhaps? Which is the catalyst?
Anyways on ice bath, methyl propionate and benzaldehyde are dripped in and it's removed from bath until rxn starts. From there it's periodically controlled with the ice bath and allowed to react a couple hours. They then add AcOH and water, and separated the organics. The aq. was extracted with some ethyl acetate, and the extracts (of course) are combined, and are washed with dilute HCl acid, then NaCl solution, followed by drying with Na2SO4. They evaporated the solvents to receive the esters, and those were taken care of by refluxing with KOH, H2O, and MeOH. The shit was isolated by removing the alc. then diluting with water and acidifying the salt to precip. the acid.

That is very similar to the process of making P2P via glycidic esters. Where an alkoxide base (OTC or purchased) catalyzed the cond. of PhCHO and 2-chloro-methyl propionate (or ethyl may be used, as well as Br or I). If you treat propionic acid with a halogen in the presence of red phos. (arrggg, thought we were past that) you get the 2-halo acid. Then estery, and you got the 2-halo-ester that is used to make the phenylglycidic esters. Which get formed in a rxn not much very different than the one above. The esters are hydrolyzed, and if I remember correcly you get the diol. Quick acid dehydration gives P2P (probably better to go with if you don't mind aquiring the rp). So just think about all that.*****

Your other logical pathway, something SWIM has a few patents on (and it's looking pretty easy and OTC also), is decarboxylation of the a-Me-cinn. acid, which gives the highly conveted propenylbenzene. SWIM is sure he dosen't have to tell you what to do with that one!

SHIT I GOTTA GO! Be back later to continue this discussion...........................

WizardX
Wizard Master

quote:An acid catalysed Aldol condensation of Benzaldehyde and Methyl Ethyl Ketone to give Methyl Phenyl Butenone ie C6H5CHO + CH3CH2COCH3 + dryHCL ---> C6H5CH=C(COCH3)CH3

Methyl Phenyl Butenone is incorrectly named. Correct names are...

Chemical names: 3-METHYL-4-PHENYL-3-BUTEN-2-ONE
Synonyms: 3-BENZYLIDENE-2-BUTANONE; BENZYLIDENE METHYL ETHYL KETONE; BENZYLIDENE METHYL ACETONE

C6H5CH=C(COCH3)CH3

Molecular Formula: C 11 H 12 O
Molecular Weight: 160.215
Accurate Mass: 160.088815
Percentage Composition: C 82.46%; H 7.55%; O 9.99%

Variant: ( E )-form
Chapman and Hall Number: DDH12-N
CAS Registry Number: 42968-14-9
Type of Compound Code(s): WE9999
Molecular Formula: C 11 H 12 O
Molecular Weight: 160.215
Accurate Mass: 160.088815
Percentage Composition: C 82.46%; H 7.55%; O 9.99%
Physical Description: Needles with a camphor-like odour
Melting Point: Mp 38-39degrees
Boiling Point: Bp 12 130degrees. Bp 1 88-93degrees

Derivative: Oxime
Chapman and Hall Number: DDH13-O Molecular
Formula: C 11 H 13 NO
Molecular Weight: 175.23
Accurate Mass: 175.099714
Percentage Composition: C 75.40%; H 7.48%; N 7.99%; O 9.13%
Melting Point: Mp 104 degrees C

Variant: ( Z )-form
Chapman and Hall Number: DDH17-S
CAS Registry Number: 53793-27-4
Molecular Formula: C 11 H 12 O
Molecular Weight: 160.215
Accurate Mass: 160.088815
Percentage Composition: C 82.46%; H 7.55%; O 9.99%
Physical Description: Pale-yellow oil

quote:The unsaturated ketone undergoes the Baeyer-Villiger oxidation with peroxy acids to give the enol ester of Phenyl propanone ie C6H5CH=C(COCH3)CH3 + RCO3H ----> C6H5CH=C(OCOCH3)CH3

http://www.sciencemadness.org/library/methyl_ethyl_ketone_peroxides.html

There were 7 different peroxides formed by the interaction of methyl ethyl ketone and hydrogen peroxide in the presence of acids and subsequently identified using paper chromatography and hydrogen iodide-glacial acetic acid as the detection agent. The different amounts of peroxides in the mixture were estimated at I 25%, II 1%, III 2%, IV 5%, V 12%, VI 45% and VII, 10%. All of the peroxides in the series are shock-sensitive and explode with considerable brisance. Form VII seems to be a precursor to all other forms when hydrogen ion (acid) was present in the MEK-H2O2 mixture. Peroxide VII evolved oxygen and yielded all other forms except I when allowed to decompose in a closed system at room temperature over several weeks.

You can make MEK peroxides to use in the Baeyer-Villiger oxidation of 3-Methyl-4-phenyl-3-buten-2-one, C6H5CH=C(COCH3)CH3

ENVIRONMENTAL HEALTH CRITERIA FOR METHYL ETHYL KETONE
http://www.inchem.org/documents/ehc/ehc/ehc143.htm

bio
Professor of P2P @ Ketone University

................ yields in both the aldol condensation and the Baeyer-Villiger can definitely use some vast improvements...................

Last 4m condensation yield was 93% (up from 84.8%) using the simplified method. So don't know what your talking about here. Molar yield is the only meaningful way to figure yield. The B/V yield of purified propanone from the ester is 55%molar with 1% H2SO4 catalyst. Lot's of room here although recycling is working out well. There is some question as to the efficiency of the hydrolysis step. If you compare similar reactions yields seem to hover around 60% without using the exotic catalysts.

.................. a lot of precursor is destroyed upon distillation. There is tarry like shit left (in the still flask) that is a bitch and a half to remove...................,

For this molecular wieght you definetly need a vacuum. Break down and buy a $10 plastic aspirator, Nals..... will pull 38mm with warm water and about 12mm with ice water.

......... SWIM is reduced to simple lab procedures .......

You can crystalize the MePhBuO directly from the condensation mix although distilling is faster and really easier. It helps when doing this to use less MEK.

...........distills the MePhButenone it's of course at normal pressures....

What temperature does it come over at atmospheric????????

If you must do this, the workup must be very thorough for obvious reasons. What are your actual yields of crystallized BuO? You should be getting at least 1.1g for each gram of aldehyde.

......... (aka the benzaldehyde) do not self condense.............

Ohh yes it will, quite easily in fact. Depending on conditions like too hot etc. This is the tar from hell as I call it which is always present to some extent. Just add some PhMe & Me2CO to the still hot flask and it comes out much easier or (if you didn't) boil it out later.

.........Anyway, more in a little while....................

bio
Professor of P2P @ Ketone University

Chemical names: 3-METHYL-4-PHENYL-3-BUTEN-2-ONE

If it's OK with you wiz; I'll keep using the trivial name.

Variant: ( E )-form

Physical Description: Needles with a camphor-like odour
Melting Point: Mp 38-39degrees
Boiling Point: Bp 12 130degrees. Bp 1 88-93degrees

I'll trust them on the physical data, Mp & Bp is what I get usually comes over at 126-132 at 12mm. The guy who wrote that must have had Vicks on his lip, lol. It does NOT smell anything like camphor to me at all. More of a subtle floral very pleasant smell. Someone else described it as a "cherry smell". The needles can be very long (as long as the container) and are pale yellow. If you don't stir the shit while crystallizing it will set as one solid chunk and then it's screwdriver and hammer time. I found this out the hard way. So if this happens to you just remelt the stuff, much easier, lol. BTW it is used as a flavoring additive in some foods but don't run out looking for it OTC as my data says less than 1Kg a year consumed in the US. Guess that's a well kept secret.

Variant: ( Z )-form
Physical Description: Pale-yellow oil

Have been saving this oil up now little by little and am wondering what to do with it. Doesn't smell near as good. If the distilled oil mixture is directly oxidized yield suffers but I don't know if it is due to the trans isomer. Shouldn't it yield the same product as the propanone is isomeric also???

Think I'll stick to the peracids that MEK peroxide sounds like some mean shit.

IndoleAmine
New Dreamer

quote:

Chemical names: 3-METHYL-4-PHENYL-3-BUTEN-2-ONE

..you mean like (E)-1-phenylpent-1-en-3-one?

'cause this is what it is in fact...

I just had understood the rxn mechanism of this whole thing, using the merck index' "name reactions" part, Chemdraw and common sense, and was pretty proud of it, and then I looked into this thread...

I think the wrong name "methyl-phenyl-butenone" originated from methylphenylbutanone like depicted below - they just differ in one hydrogen missing, so..

(made using ChemDraw)

Bio: could you perhaps do us a favor and explain the temperature control during the Baeyer-Villiger a little more detailed? I would really appreciate it, as it seems as if the right temp. would be essential for good yields in this step, and controlling it quite a hassle...

Greets, I_A

IndoleAmine
New Dreamer

Ehm - I think I was wrong and WizardX was right (sorry for the inconvenience)...

My unsaturated ketone would give a wrong ester and just 2-phenylacetaldehyde upon hydrolysis, whereas with (E)-3-methyl-4-phenylbut-3-en-2-one, the ester formed would result in P2P upon hydrolysis. Apparently I made a mistake while figuring out how the aldol condensation works, thought the MEK would condense with the CHO at the shorter alkyl chain, not at the ethyl side...

sorry.

psuedonymph
WD Secretary of the Interior: Kung-Futon Master

BTW it is used as a flavoring additive in some foods but don't run out looking for it OTC as my data says less than 1Kg a year consumed in the US. Guess that's a well kept secret.

Not anymore it isn't.

I_A, you might find this interesting:

The oxidation occurs only at 60–65C, sluggish below 60C and above 65C the oxidant decomposes.

Since the reaction rates were measured only in a narrow range of temperature and the oxidation proceeds via two kinetic routes, the thermodynamic parameters were not determined.

http://malina.ichf.edu.pl/pjch/pj-2001/pj-2001-07/07kar.pdf

IndoleAmine
New Dreamer

Perhaps adding a bit methanol during the baeyer-villiger would help in making the temp control easier? It refluxes at 60-67°C, and perhaps this helps, similar to DCM, refluxing at 40°C, in a performic with subst. propenylbenzenes, and keeping the rxn temp in the optimum range..

Maybe other solvents like chloroform (CHCl3; bp 61-62°C) are even better than MeOH?
(are alcohols inert in a B.-V. oxid.? I guess not..)

Anyone want to comment on this idea?

psuedonymph
WD Secretary of the Interior: Kung-Futon Master

quote:Originally posted by IndoleAmine

Perhaps adding a bit methanol during the baeyer-villiger would help in making the temp control easier? It refluxes at 60-67°C, and perhaps this helps, similar to DCM, refluxing at 40°C, in a performic with subst. propenylbenzenes, and keeping the rxn temp in the optimum range..

Maybe other solvents like chloroform (CHCl3; bp 61-62°C) are even better than MeOH?
(are alcohols inert in a B.-V. oxid.? I guess not..)

Anyone want to comment on this idea?

Can anyone see why this reaction would not work just as well or better in an acidic (no buffer) Performic/Peracetic in DCM?

Question: can anyone recommend a practical method for the decarboxylation of alpha methyl cinnamic acid?

Soda Lime?

bio
Professor of P2P @ Ketone University

..............Perhaps adding a bit methanol during the baeyer-villiger would help in making the temp control easier................?

Not a good idea I think. Will have to dig up the articles which I just found recently on some H2O2 oxidations where methanol was tried as solvent. For some reason MeOH lowers yield a lot (50% or more). One of these examples was a B/V. Acetone would be a good choice as it is not oxidized under B/V conditions. The patent twodogs referenced for perborate lists a few compatible solvents, but I don't think this is necessary as adding the perborate in portions to the MPB solves the temp control problem in a RT running water bath if you want to keep below 30deg. If running at 50-70deg adding the perborate to HOT substrate/AcOH over 30-60 min accomplishes the same thing surprisingly. If internal temp rises too much then place in a cool or ice bath until stable then keep the bath at 60-70deg. The initial exotherm is over in an hour or so. No noticible exotherm when running it RT. This should also be the case when using peracetic premade. Although the water content is higher with it if using 35% H202 which needs to be empirically determined by experimental testing.

A few have said they have done this yet no one seems willing to participate in experiments except the 2 bees that I lost contact with.
It takes a long time to perform numerous experiments when one has only one set of glassware and a long time to type all this shit.

IndoleAmine · Dreamreader Deluxe

IndoleAmine · Dreamreader Deluxe

bio · Working Bee

Terrific IndoleAmine. Way to go!

Is there any reason you can see that the lower acidity Peracetic would not return a similar yield? and of course peracetic made from perborate beforehand, which is my next experiment. With 1% sulfuric should give near complete conversion in 3-4 hours w/ only 4 moles water then just dump 'er in (slowly). Do NOT try this at home as it could be hazardous to your health neverminding the property.

I like the easy separation of the MPB and this is progress to the quant yields that should be attainable.

BTW you were supposed to get 95% what went wrong? Razz

Guest · Fri Mar 04, 2005 11:40 am

This is excellent material, Indoleamine,
Well done,
This route needed a lift in awareness, as as you have shown, it's synthesis can be broken up into long but readily available chemicals for the hobbiest,
Benzaldehyde, MEK, Formic or acetic, and you have, what I believe
a pioneering method, for the chemist,

There are many good routes, now to Benzaldehyde,
Toluene,Cassia Oil ,persulfate oxidation, anode/cathode,etc

This is brilliant chemistry

And a good yield too,
Nice work, Bio and Indoleamine!, Wink

syn

IndoleAmine · Dreamreader Deluxe

Thanks syn! Wink

..-g-