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Polverone
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| Quote: | Originally posted by garage chemist
In another thread (sec. alcohol -> ketone) we recently talked about the FeBr3 catalyzed H2O2 oxidation of benzyl alcohols to benzaldehydes in over
80% yield. TCCA/KBr in DCM can also be employed for the oxidation of benzyl alcohol.
I also must say that benzyl alcohol is the best precursor to benzaldehyde you can get, much better than toluene.
I even think it would be worthwhile to make benzyl chloride from toluene, hydrolyze this to benzyl alcohol and oxidise it.
How is the availability of benzyl alcohol in the US? |
If you have benzyl chloride, can't you go directly to the aldehyde with the Sommelet reaction? I've never seen benzyl alcohol for sale in a brick and
mortar store, but it is available online from numerous suppliers and is unregulated so far as I know. Best price I've seen recently is $40 for 1 US
gallon (3.785 liters).
PGP Key and corresponding e-mail address
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evil_lurker
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The Sommelet does work, but keep in mind that benzyl chloride and benzaldehyde's boiling points are practically the same for all intents and purposes
so if the reaction doesn't go to completion your gonna have contaminated product.
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Maja
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But you can easily purify benzaldehyde by bisulfite...
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roamingnome
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Prohibition my friends will soon be over.
You see in a free and ever growing educated society were commerce is king and the transport of resources and information never end, braking points are
reached.
Today millions of dollars go into the commerce of beer and wine making. Many are employed to raise the grapes. The "controllers" realized that
regulating sugar and water and harmless little ole yeast would be futile and immposible, hence prohibition was repealed.
The advanced collective mind of scientific thought is bringing forth such techniques and wonders that soon my friends no man shall controll.
in other words fuck the DEA
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Baphomet
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Roamingnome you have a point in that it will never be feasible to completely stop synthesis of illicit substances. But I don't think the governments
are trying to eradicate it completely anyway. The true aim of their bans on various chemicals is to make synthesis as difficult as possible. For
example it would take a lot longer to make meth using matchbooks and seaweed.
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roamingnome
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a few months wiser, i think prohibtion might be around for a bit....
the cheapo almond flavor that I found and grabed a bunch of to perform some small scale tests etc.....turns out to ultimintaly have been a complete
distraction from more important issues....
I poured 8 or so bottles approx 500mls into distilation setup
applying vaccuum i suspect the alcohol was coming off at 20 degreees
the next fraction assumed to be water started coming over at 55-60 degrees
after shutting down the process the liquid left in the flask had ZERO smel
and appyling the patented "gil" taste test, it was more water!
the distillate also had zero smell...
my point is i can only assume the aromatic oil just evaporated off
i know thats its aromatic and volitle, but its boiling point is 179.1 here
I guess ill head to the getto and salt the water till a layer forms???
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picketfence
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| Quote: | Originally posted by Organikum
Benzaldehyde is a list I chemical and watched. If you cannot get oil of bitter almonds locally OTC, I wouldnt recommend to order it from anywhere.
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^That's right.
This can be made with toluene and ammonium persulfate in excellent yields, however it consumes a lot of ammonium persulfate.
Ammonium persulfate can be procured at electronics shops for some purpose which i dont give a shit about.
But again, myself I wouldn't want to be caught with a listed, or for that matter order a list chemical.
There's exceptions now though. See phosphorus and iodine are both listed items, however psuedoephedrine is no longer available as in oz atleast it's
been replaced by phenylephrine, so they could never even get you for conspiracy - that's just my opinion though.
[Edited on 22-1-2007 by picketfence]
[Edited on 22-1-2007 by picketfence]
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Coldfinger
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| Quote: |
This can be made with toluene and ammonium persulfate in excellent yields, however it consumes a lot of ammonium persulfate. |
the ammonium persulfate is used as an etching compound for production of PCBs for electronics, it by itself is no challenge to find.
However, the oxidation itself looks better on paper than it is in practice, often the toluene will not be fully oxidised and will only result in
benzyl alcohol, or it will be oxidised too much and you are left with benzoic acid. It is also an exothermic reaction and heating it too rapidly or
from experience, to over 70deg C. it tends to get into a 'runaway' situation, where it will boil rapidly, with alot of the liquid shooting out of the
condensor or ending up all over your workspace.
I am not saying it is impossible, it is just a bit more sensitive than it appears.
| Quote: |
There's exceptions now though. See phosphorus and iodine are both listed items, however psuedoephedrine is no longer available as in oz atleast it's
been replaced by phenylephrine, so they could never even get you for conspiracy - that's just my opinion though. |
i disagree, just because something is no longer available OTC does not mean that you can not be charged with conspiracy to manufacture.
Pseudoephedrine is still highly illegal to possess, in my part of the world anyway. Someone would have to be out of their mind to even consider
messing with it.
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roamingnome
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i think one needs to step up to zeolites if you really want a good way to convert toulene to benzaldehyde
Zeolite Y
http://www.personal.utulsa.edu/~geoffrey-price/zeolite/fau.h...
...shoot can find the other refs at this time....
http://www.springerlink.com/content/n16548546t166jx5/
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bio2
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So after all these years of discussing PhCHO
from bitter almond extract or diluted flavoring
has anyone published a procedure that's workable?
This doesn't seem so difficult after all.
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Sauron
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Anyone can say "fuck the DEA" as talk is cheap.
However if the DEA says "Fuck you!_ you might find it costly.
Or in other words, to paraphrase John F.Kennedy,
"Ask not what your country can do for you. Ask what your country can do TO you."
I used to say "Fuck the ATF". And in 1975 I had a run-in with an ATF undercover agent who tried to clumcily entrap me. I made a fool of him. For the
next ten years he waited to get even. One day he got his chance and he took it. It was such an egregious case Jack Anderson wrote a column about it.
Anyway, my advice is, don't go out of your way to piss off powerful agencies.
Life will supply you with enough problems without all that.
PS to above:
Unless the USC has seriously changed, a criminal conspiracy requires at least two conspiraors. There's no such thing as a conspiracy of one. An
individual cannot conspire with himself.
Furthermore with exception of some tax codes and some firearms codes that are really tax codesa, all criminal laws place the burden of proof of
criminal intent on the prosecution. If you are not using benzaldehyde to prepare drugs or precursors for drugs that are scheduled, then where's the
criminal intent? (n legal jargon, the phrase of art is "mens rae".
Naturally if you are a drug user, drug dealer, have a drug record, associate with druggies, etc. then the prosecution will have an easy time with this
burden.
[Edited on 24-1-2007 by Sauron]
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picketfence
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| Quote: | Originally posted by Coldfinger
| Quote: |
However, the oxidation itself looks better on paper than it is in practice, often the toluene will not be fully oxidised and will only result in
benzyl alcohol, or it will be oxidised too much and you are left with benzoic acid. It is also an exothermic reaction and heating it too rapidly or
from experience, to over 70deg C. it tends to get into a 'runaway' situation, where it will boil rapidly, with alot of the liquid shooting out of the
condensor or ending up all over your workspace.
I am not saying it is impossible, it is just a bit more sensitive than it appears. |
No you see I've actually done the rxn and fractionally distilled - from memory the purity was >90% as was the yield.
The patent isn't posted here.
| Quote: | | i disagree, just because something is no longer available OTC does not mean that you can not be charged with conspiracy to manufacture.
Pseudoephedrine is still highly illegal to possess, in my part of the world anyway. Someone would have to be out of their mind to even consider
messing with it. |
Who would keep ephedrine though except a desparate, dumb meth cook who has no other options?
The only option is a plantation of ephedra sinensis or other high yielding (like 1% at best) and a small garden with a few plants is just laughable.
And they can forget the overhyped biosynthesis with benzaldehyde and acetaldehyde, that was never an at-home, in-a-bucket job as many wanted to
believe it was, it requires highly controlled conditions to reach L-PAC.
Anyway, I partially agree with you, as being caught with anby listed chemical including RP would not be nice. However there's better alternatives to
phosphorus that're non suspicious, and iodines used in photography.
[Edited on 24-1-2007 by picketfence] |
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Hilski
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| Quote: | | And they can forget the overhyped biosynthesis with benzaldehyde and acetaldehyde, that was never an at-home, in-a-bucket job as many wanted to
believe it was, it requires highly controlled conditions to reach L-PAC |
{EDIT} Never mind. It's not even worth arguing about.
[Edited on 24-1-2007 by Hilski]
\"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety. \"
- Benjamin Franklin
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picketfence
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Exactly - that's the past.
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einstein(not)
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Bisulfite Addition Weirdness
I just tried bisulfite addition to imitation almond extract with weird results. The extract I'm using contains the following ingrediants:
Water,Alcohol(36%) and Benzaldehyde.
The following volumes were used in all experiments.
50ml extact
50 ml ether,hexane(starting fluid)
50ml saturated sulfite solution
Experiment 1
The extract was dryed with oven roasted rock salt for 2 hours decanted and ether was added. The mixture was shaken vigorously in a sepratory funnel
and the lower phase drained off. The lower phase still had a strong smell of benzaldahyde. The upper layer was dumped into bisulfite solution and
stirred for 5 minutes. No precipitate was detected. The same was repeated with the lower layer with the same results.
Experimient 2
Same as above except the extract was dried with molecular seives. Same result.
Experiment 3
Same as above except the extract was dried with calcium chloride(damp-rid). This time when the lower layer was dumped into bisulfite solution a
white suspension resulted. When this suspension was then added to the lower layers of the previous experiments they became white suspension as well.
I can tell that some of this suspension is bisulfite adduct but I'm not sure it all is.
So my question is does calcium chloride react with bisulfite,alcohol or benzaldehyde is some way that caused this? Or is there an additive in the
extract to prevent separation? Is the procedure flawed? This is my first attempt at bisulfite addition.
[Edited on 15-5-2009 by einstein(not)]
[Edited on 15-5-2009 by einstein(not)]
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DJF90
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Bisulfite addition usually requires adding the aldehyde to a solution of sodium bisulfite and then cooling, can take an hour or so to form; at least
it did in the procedure I read IIRC.
[Edited on 15-5-2009 by DJF90]
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bquirky
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I dont relly know anything about organic chem so im likely way off
but if your looking for large amounts of almond extract why not just buy a bunch of almonds and extract the oils yourself ?
at least then you would know that it contains what almonds are supposed to contain 
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einstein(not)
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Where can I find detailed information on the proper precedure? One suitable for a beginner. Preferably with explainations why each step is done
in a particular way.
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Nicodem
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There are plenty of examples in the literature, just pick one and try it out.
CaCl2 form chelates with alcohols just like with water.
Bisulfite adducts of aldehydes are generally water soluble, some better some worse. So if your goal was to get a precipitate of the adduct, what was
the point in having a biphasic mixture? Though it is true that aldehydes can be extracted in to the aqueous NaHSO3 solution in the form of the
bisulfite adduct (RCH(OH)SO3Na), you do not seem interested in extracting the adduct, but rather precipitating it (that is if I understood correctly,
as it would be nice if you would bother describing what you do and what you want more properly).
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Sedit
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I recently figured I would attempt to extract the BzO from the tinctures found in the super market and the results I obtained where unimpressive to
say the lest. There was so little BzO in them is wasn't even funny. Just a few very fine droplets of oil from 3 bottles that I didn't even waste my
time attempting to extract it. I know that not all extracts are made equally but for anyone that wants to attempt this dont spluge and by 20 bottles
until you are sure there is a decent amount in there to make it worth extracting in the first place.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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Arrhenius
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There are synthetic bitter almond oils available that are >90% benzaldehyde. I found it very easily purified by fractional vacuum distillation.
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einstein(not)
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Well I'm trying to separate the benzaldehyde from the extract. I tried vacuum distillation once and ended up with red cinnimon smelling oil.
Learning for me has always been a hands on process and what I was hoping to learn with these experiments is how to properly extract a disolved
aldehyde from a solution. Imitation almond extract was available so that's what I used. As was the starting fluid. I eventually I would like to
move on to actual aldehyde synthesis but without knowing how to extract the finished product what would be the point.
One thing I've learned is that I don't understand how to extract properly from alcohol solutions.
I considered basic A/B extraction but after my failure with vac. distillation I opted for what sounds like a milder method.
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Arrhenius
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Really, vacuum distillation is a slam dunk if your starting oil has a good amount of benzaldehyde in it, and if your vacuum distillation setup is
legit. I'll post a writeup if you guys don't believe me.
Acid-base extraction will not work with benzaldehyde, as it doesn't contain an acidic or basic moiety. Can you explain more thoroughly the procedure
you used? Where does the starting fluid come into the distillation?
Benzaldehyde is quite fragrant, and any almond essence or almond extract product used for cooking is likely not to have very much in it. Products
specifically for fragrance applications are likely to be quite concentrated. It really depends if you want the benzaldehyde, or you want the
challenge of trying to squeeze a little bit out of an OTC product. If you're starting with an alcohol solution, you can pump off the alcohol with a
vacuum pump at room temp.
One thing to note with distillations is that if you have water present, you will actually be conducting a steam distillation, and you won't
fractionate your mixture.
[Edited on 15-5-2009 by Arrhenius]
[Edited on 15-5-2009 by Arrhenius]
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einstein(not)
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Starting fluid wasn't used in the distillation. Only the bisulfite procedure.
Vacuum distillation experiment
236ml of imitation almond extract (water, alcohol(36%) and benzaldehyde) was placed in a 500ml RBF 24/40 single neck to which was connected a
thermometer adapter with a sloped side side connector. A 300mm jacketed allihn condenser was attached on the receiver end to a 45 degree vacuum
adapter attached to a 500 erlenmeyer flask.
The flask was place in the mantle and slowly heated over approx. 3 hours to 110C while vacuum was applied. The reading on the gauge showed 15 which
I assume is inches Hg. Condenser coolant was maintained at 0C. Distillate came over at approx. 2 drops per second. Almond smell filled the work
area I assume from the vacuum pump. When boiling slowed almost to a stop the mantle, vac. pump, and coolant pump was turned off. The residue was
approx. 15ml of a dark red oil smelling of cinnimon. Washing with 20ml of Dh2o made no difference in color.
Wonder if imposing a wash bottle with bisulfite solution between the vacuum pump and the receiver might catch any losses?
If there is alcohol present along with the water is it still a steam distiiation?
[Edited on 15-5-2009 by einstein(not)]
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Arrhenius
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So what color was the distillate? In a vacuum distillation the benzaldehyde should come over as a clear fraction. If you have a vacuum gauge on the
setup, try using a nomograph to correct the BP and see if you're close to that of benzaldehyde. At this point the pot residue should be unwanted
contaminants.
If you want to start with that almond extract, I think you should try to get the benzaldehyde away from the water first. Dilute the extract with
water, extract with ether or ethyl acetate, dry with magnesium sulfate if possible, and strip off the solvent. This will prevent water from messing
up your distillation.
Your loss in the vacuum pump should be really negligible. The boiling point of benzaldehyde is a bit too high for your pump to be stripping it off of
the distillate side of the apparatus, but your nose is really sensitive to it. Don't worry about losses there.
Also: 3 hours sounds like a long time for a distillation. It's okay to get it going a little faster. Generally, applying heat will promote side
reactions, so it's favorable to get your product out as quickly as possible.
[Edited on 15-5-2009 by Arrhenius]
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