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Organikum
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favour the formation of benzalchloride
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Your ratios are wrong then. This favors benzylchloride I might say.
TCCA = 232g/mol
500g TCCA is roughly 2 mol, is 3 mol Cl2 is theoretically enough to chlorinate 6 mol toluene to benzylchloride or 3 mol toluene to benzalchloride.
1000 ml toluene is about 10 mol.
I didnt do the workup by now, but somethings sketchy it seems.
We will see.
/ORG
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ballzofsteel
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Yes you are right.
So sorry,Wasnt thinking right.
I made a mistake when writting that post,thinking that 1 pool tab=100g when they are in fact 200g,and I used 5 of the suckers = 6mol cl2.
Ill still work this up,as it should contain at lleast a portion of benzal/benzyl chloride.
After sitting over night the yellow seems less intence leading me to believe it may just be the mix I was after.
[Edited on 23-12-2004 by ballzofsteel]
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Organikum
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to good to be true - for me
The workup of the TCCA/water/toluene via Sommelet produced zero/nada/nothing on benzaldehyde.
It might be
- fucked up Sommelet (not very likely)
- hydrolysis of BzCl to BzOH because I waited too long and/or because this happens anyways.
I guess that hydrolysis is the main problem of this reaction.
Will try this with hypochlorite next time, maybe that works better.
Adding sodium carbonate might help though, or using the di-chloroisocyanuric acid sodium salt, this would be better soluble too.
what a fucking christmas
/ORG
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IPN
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...or using the di-chloroisocyanuric acid sodium salt, this would be better soluble too.
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I was organizing my chems and found a 1kg box of granulated sodium dichloroisocyanuric acid and remembered this thread. 
So now I have 80g of toluene, 50ml saturated solution of SCCA in water and 1g of hexamine refluxing in a water bath. I'll let it be there for 3h
or so and then add sodium carbonate and reflux that. I hope I get something.
Heres a vid of the mix refluxing: 
http://koti.mbnet.fi/otto2000/toluene_scca_reflux.MOV
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garage chemist
chemical wizard
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Sorry for bringing up old threads... but its better than opening a new one.
I hope that this hasn't been posted before.
In "The war gases", I found something interesting about benzylchloride:
"Under the influence of weak oxidisers, like calcium nitrate, barium nitrate etc., the benzylchloride is converted to benzaldehyde after the
following equation:
2 C6H5-CH2Cl + Ba(NO3)2 -----> BaCl2 + C6H5-CHO + NO + NO2 + H2O
With strong oxidisers, like chromic acid, it is converted to benzoic acid."
Also, in this book, benzylchloride is prepared by bubbling chlorine through 100g toluene with 5g PCl5 as the catalyst (until the weight has increased
by 35g). The PCl5 could likely be replaced with the same molar amount of red P, as it reacts with chlorine rapidly to form PCl5.
I planned to chlorinate toluene to benzylchloride, hydrolyse this to benzyl alcohol and oxidise this to benzaldehyde, since benzyl alcohol is oxidised
to the aldehyde much easier than straight toluene.
But the hydrolysis apparently isn't necessary, just adding some barium nitrate seems to produce benzaldehyde.
Reactions conditions aren't named, but if you see red nitrogen oxides evolving from the reaction, you know that it is working.
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garage chemist
chemical wizard
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Will adding red P (gets converted to PCl5 rapidly) as a sidechain chlorination catalyst interfere with the added hexamine?
I don't know too much of the chemistry of hexamine... and if there's a chance that bis(chloromethyl)ether forms, hexamine is out of the
question. Bis(chloromethyl)ether is ultra carcinogenic and as toxic as phosgene.
Drying + distilling the toluene before chlorination, heating and lighting the flask with a halogen lamp should prevent ringchlorination as far as
possible, even without hexamine.
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S.C. Wack
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On a slightly less than 1 gram scale:
Attachment: jacs_105_7672_1983.pdf (208kB)
This file has been downloaded 1690 times
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The_Davster
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| Quote: | Originally posted by Organikum
US3691217
Benzalchloride and acetic acid plus tin(II) or tin(IV) chloride yields benzaldehyde and chloroacetic acid.
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I just read through that patent and saw nothing even mentioning chloroacetic acid, the reactions there produce the acid chlorides, nothing on the
chloroacids. Did I miss something there or did you mean to say acetyl chloride instead of chloroacetic acid?
[Edited on 28-2-2006 by rogue chemist]
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Organikum
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Hell thats so long ago I hardly can remember it. But I remember all the pain this chlorinations gave me.
Sorry, I won´t look it up, I am completly into non-toxic transformations now, I had my share of lachrymators and more then I ever wanted. Passing out
under seizures from cleaning a flask with chloroacetone did it for me. Cost me expensive glassware (don´t give a shit) and braincells (thats bad).
/ORG
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ordenblitz
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I have had some success using TCCA.
A 250 ml. flask was equipped with overhead stirring, a reflux condenser, thermometer and a free neck with a stopper. Therein was placed toluene,
H2SO4/H2O 50/50 mix and a pinch of hexamine.
Heat was applied and when the temperature reached ~80º, large chunks of TCCA was added one at a time through the free neck of the flask. The TCCA
chunks were broken from a large pool chlorinating tablet sized to just barely fit through the 24/40 neck. It was easy enough to add the chlorinator by
momentarily pulling the stopper in the neck; quickly dropping said chunk, then replacing the plug. I had nothing resembling a run away and it was no
problem to control the foaming with good stirring. The additions continued periodically, about every 8 to 10 minutes, as the temperature rose through
100º. I was going to wait until 100º to begin additions but was nervous about what might happen upon the first drop. I have to say that in
retrospect it wasn't as hard as one would expect. I had plenty of time for the additions as the foaming never made it up into the reflux condenser.
Remember though.. big chunks.
The final temperature was roughly 130. After the requisite amount of TCCA was added and the reaction ceased, the contents were cooled, suction
filtered and distilled. The result was an equal mixture of ring chlorinated product as well as the side chain chlorinated specimen coming over at
176º
I do think that if the first additions are commenced after reaching 100º, a good deal more of the desired product could be had.
I did repeat the process deciding to skip the filtration step, opting to separate the products directly by distillation. Not a good idea. Upon heating
the combined material began to rapidly darken and get viscous. Eventually it turned into a tarry mass of black crap that nothing distilled from until
the temperature was well over 200. What came over was a lovely maroon oil. What it was I have no clue.
Some pictures:
http://img95.imageshack.us/img95/3138/setup9id.jpg
This picture was from a previous attempt where the plan was to drop powdered TCCA down the condenser where upon it could be gradually reflux washed
into the reaction. It did not go as planned as was abandoned.
http://img75.imageshack.us/img75/9335/addition13kq.jpg
http://img75.imageshack.us/img75/5899/addition22du.jpg
http://img75.imageshack.us/img75/2450/midway3us.jpg
The first picture was immediately after the first TCCA addition, the second two or three chunks in and the third picture from about 40 minutes into
the reaction.
http://img45.imageshack.us/img45/437/nearend8ph.jpg
This is how it looked not long before the foaming subsided and the cooling was begun.
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JohnWW
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Can benzyl chloride be used as an intermediate in the preparation of DDT? I would think so.
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Nicodem
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No, you need chlorobenzene.
But if you do have benzene you can chlorinate it with TCCA under electrophilic conditions (H2SO4 catalisys). Actually I don't know how Ordenblitz
obtained so much benzyl chloride at all since the conditions he used were for electrophilic substitution mostly (except for the higher T and the part
of toluene that got chlorinated in the vapor phase). Yet it seams he was after benzyl chloride and not ortho/para chlorotoluene.
I would never do something like he did though. TCCA in dilluted H2SO4 hydrolises to HClO which in highly acidic media easily dehydrates to Cl2O.
Vapors of toluene and Cl2O are a highly instable mix that can explode any time, especialy by the presence of light. Anyway, you certainly don't want
to heat the reaction mixture if you want to chlorinate benzene. The reaction procceds at room temperature if left stirring for two days or is done in
5 hours at 65-80°C (see the original paper J. Org. Chem, 1970, 56(3), 719-722).
…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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ordenblitz
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Some time ago, working from said reference for the production of chlorotoluene, I was not paying close enough attention to temperature control and
inadvertently let it climb over 100°. Upon filtration and distillation I was surprised to collect a small amount of benzyl which I did not think was
probable from this reaction.
The above was done simply to see if the conditions could be altered slightly to increase the production of side chain chlorinated product, for which
incidentally I have no use. This was done for curiosity sake and was posted here merely for discussion purposes.
Nicodem:
Do you think that changing the reaction conditions by raising the temperature from 80° to 100° increases the danger of this reaction substantially
over that of the published procedure?
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Nicodem
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I know from the equilibrium constants of TCCA hydrolysis to HClO (0,00067 mol/L) and HClO dehydration to Cl2O (0,00357 mol-1L-1 at 20°C) that
substantial amounts of Cl2O is formed under your reaction conditions (especially under the acidic and reflux condition). I also know that a correct
vapor mixture of Cl2O and toluene explodes violently and unpredictively without the need of a spark. So, my answer is: Yes, it is potentially very
dangerous, especially if working with such large amounts. Going from 80°C to reflux is an enormous difference for what regards the composition of the
gases above the liquid phase.
This is what I think about why you got some benzyl chloride:
Cl2O and HClO are capable of benzylic side chain chlorinations in the vapor phase even if barely any or no light is present. So I guess the reason why
you got some benzyl chloride besides the normal products is because you used reflux conditions. I would assume a similar thing happens when using the
famous "Loomis patent" method (and that's probably why it is so prone to dangerous runaways) only that no ring chlorination can happen there since the
hypochlorite is insoluble in toluene and the reaction probably proceeds only in the vapor phase between the solid and liquid boundary (Cl2O, Cl2 and
HClO vapors being reversibly formed in an equilibrium from “calcium hypochlorite” at that temperature while at the same time these vapors are
prevented from dissolving/reacting in liquid toluene by the reversible process – reaction with the left over calcium hydroxide).
The reaction conditions for side chain chlorination of toluene with TCCA are published in that same JOC paper. No strong acids must be present to
avoid ring chlorination and a radical initiator is used to start the radical chain reaction. The authors used dibenzoyl peroxide as radical initiator
which is also the most common initiator used for radical polymerizations. Hence it is available OTC, at least in my country, as a solution in methyl
ethyl ketone (MEK). You can leave the MEK solution to evaporate at room temperature on a plate (benzoyl peroxide explodes when heated!) and dissolve
what remains in the toluene that will be used for the reaction. That is all you need to get benzyl chloride in a safe and clean way.
[Edited on 15-7-2006 by Nicodem]
…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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Ephoton
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I have never had a single prob with chlorinating toluene with hypochlorite ions.
they key to a safe reaction of course is to stay under 105C this is very easy to do.
just use a boiling water bath. as for dryness of hypochlorite and toluene this does
play a major factor. but if you put more toluene in the mix than needed then distill a small amount out. the water will go with it as an azeotrope
too easy why not just do it the old fashioned way. every time it works. never a
prob its the easiest one in the book.
personaly ive tried many ways to benzylchloride and this one has never failed. and for keeping the hypo ion covered with toluene to keep it from
detonating. this is not true its the temperature that the reaction is done at. I have done many of these going for many different products trying to
play with baker light like substances. (wondered if benzyl alcohol would work instead of phenol which it does not in my books) the only problem that I
can see with this synthesis is the fact you have to filter the product before distillation very nasty for the eyes and nose. make sure the filtration
is fully enclosed so as not to let out fumes. and if you have to sniff it to notice the sting you have done some thing wrong (which I can not see as
its so dam easy to do)
psycho kitty was the one who first suggested the use of red phosphorus for the initiator of the chlorination I believe on the hive. She gave patent
refs too but I don't have the time to dig them up. she swore by it and I have never had a problem with her posts working. still to try the TCCA and I
will one day but not for a bit.
e3500 console login: root
bash-2.05#
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evil_lurker
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Tonight I attempted to chlorinate some toluene using chlorine gas generated by the reaction between MnO2 and HCl. The MnO2 was pottery grade, and the
HCl was off the shelf hardware store 31%, and the Toluene was "Ace Hardware" brand, once distilled.
The equipment used was a 2L addition funnel, 3L flask, Claison adapter, and gas inlet adapter (outlet in this case). The gas generator was hooked
onto a 500ml pyrex gas wash bottle loaded with "liquid lightning" sulfuric acid drain cleaner, a trap flask, check valve, and finally into the
chlorinator. The chlorinator consisted of a 3 neck 1L flask with inlet adapter, gas dispersion tube, thermometer, 200mm reflux condensor, and finally
another inlet adapter for discharging HCl.
Heat was provided by an embossing tool that looks like a hair dryer and light by a 500watt halogen bulb minus the glass shielding.
Total charge, 1400ml of muriatic acid, 3.5 moles of MnO2, and 552g (approx 6 moles) of Toluene. The heat tool was only able to get the flask up to
around 100ºC, however once the light was turned on it quickly refluxed, and did so at a rate that the heat tool was turned off and all heat provided
by the halogen light for the rest of the reaction (amazing... refluxing a damn 1L flask with a freaking LIGHT of all things).
Once the flask was brought up to temp, the muriatic acid was allowed to drip onto the pre-moistened MnO2. Nothing! I was like WTF, that asshole ripped
me off, this ain't MnO2! So I said F-it and pretty much added in about 1000ml into the reactor. After a minute or two, some Cl2 gas began began to be
formed. I instantly thought "oh crap, massive runaway time" but amazingly the gas generation never did really get out of hand... in fact it never
really did much of anything. So I added in the rest of the muriatic acid. Still no increase inflow with only a small stream of Cl2 being produced.
Flow slackend after about an hour and a half, and magnetic stirring was begun to compensate for the reduced flow.
After 3 hours the chlorine gas flow was barely going, and so the reaction was terminated. The contents of the flask were still clear and almost
colorless, even though no Hexamine was added as a catalyst/iron sequesterant. The contents of the flask were then transferred to a 1L flask for
distillation and weighed.
Then the crapper. Total weight increase of crude product 8 freaking grams!!!! ARRRGH! I was hoping for at least 1-2 moles worth, but the yield of
crude product was pathetic.
Last time I attempted to add HCl to MnO2 massive clouds of chlorine gas were emitted, but this stuff was crappy to say the least. Even on the outside
of the building there was barely any flow coming out of the discharge hose... swim was expecting massive clouds of HCl but there really wasn't squat
coming out.
I think I got ahold of some bad MnO2 if there is such a thing. Going to try tomorrow with some TCCA as a chlorine source and see what happens.
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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garage chemist
chemical wizard
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Its strange that you even got a good chlorine production from MnO2/HCl once, because the very slow reaction you described is what usually happens.
HEAT man! MnO2/HCl wants to be heated to near boiling temperature before it outputs chlorine with any usable speed!
TCCA/HCl also needs to be heated well in order to produce the theoretical amount of chlorine. Also finely powder the TCCA before using it, coarse
granules will coat themselves with cyanuric acid and not react fully.
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evil_lurker
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Well... your right... went outside to clean up and in the flask was lots of unreacted MnO2.
I got a sneaking suspicion after a few minutes that one might have to heat the stuff up to get decent Cl2 production... but didn't want to set back up
my water bath since I was using a RBF and a rather large bulky setup.
All I can say after cleaning up is thank god for respirators... chlorine is hell to work with, especially on a large scale.
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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garage chemist
chemical wizard
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Your procedure wasnt a failure, you just found out that chlorine is not produced at room temperature. Your chemicals are still fine, they just havent
reacted. Your synthesis hasnt begun yet.
All you have to do is heat the toluene to reflux again and then heat the chlorine generator.
I hope you didnt throw out the chemicals! It would be a shame if you didnt continue the synthesis.
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Magpie
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FYI, from Laboratory Studies in Chemistry by Bradbury (1923):
1. Prefered method of Cl2 generation:
Place crystals of KMnO4 1 cm deep in a 300mL flask supported by a ringstand with a wire gauze. Place a small flame 8cm below the flask. Using a
dropping funnel allow HCl to fall drop by drop into the flask.
"...the production of gas is under perfect control, and the method is greatly superior to the use of hydrochloric acid and manganese dioxide."
2. Alternate method:
"On account of historical interest of the reaction, some teachers may prefer to use manganese dioxide. In that case the dropping funnel is replaced
by a thistle tube running to the bottom of the flask. Enough concentrated hydrochloric acid is added at once to cover the manganese dioxide, and a
gentle heat is applied."
[Edited on by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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evil_lurker
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Bah. I switched over to TCCA and HCl... still using the 12 theoretical mole amount of chlorine... all it takes with the TCCA put out massive amounts
of chlorine is to just slooowly drip in the HCl and then heat when the flow slackens..
This time the reaction ran much more smoothly, albeit there were a few hiccups when a check valve I was using stopped up... that was messy to say the
least... thank god for ventilation fans.
Only other problem I ran into was that the sulfuric acid washing bottle however creates significant back pressure on the generator and slows down the
generation of Cl2.
Total time of chlorine generation was approx 4 hours.
Its distilling now so hopefully I'll know the yield in about 2-3 hours.
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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evil_lurker
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Well it got distilled. Total for a 6 mole run boiling over a 5ºC range = 108g
I distilled at atmospheric and there was quite bit of dark liquid in the flask. I estimate with fractionation that over a mole could be had as the mix
I distilled off had quite a bit of benzyl chloride smell to it.
Anyways, my yields suck. 
For now anyways.
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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bio2
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.......Only other problem I ran into was that the sulfuric acid washing bottle however creates significant back pressure on the generator and slows
down the generation of Cl2...........
To dry your gas with H2SO4 it is not necessary
to put the dip tube to the bottom of the wash bottle.
An inch submerged is enough. This makes a good flow estimating device also by counting the bubbles.. You can swirl the bottle ocassionally if you
like...
When doing a procedure for the first time it is always
best to do it on a small scale to identify the pitfalls.
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evil_lurker
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Yeah I heard that... but there ain't much smaller I can go using the equipment that I have.
I think my biggest problem, is the fact that I was using the wrong kind of light (halogen lamp).
From the website http://www.faizkaskar.8k.com/light1.html for chlorine molecules to disassociate the light must have a wavelength shorter than 488nm. Any higher
wavelength than that just does not carry sufficiant energy to break the bond.
From what I could find, a typical halogen spectrum looks like this:
If one notices, the spectral output barely reaches into the sub 500 range... so even though there is a shitload of light put out by a 500watt halogen
bulb, the light just ain't got enough energy to work.
The ideal solution would be a 20,000K metal halide light fixture, somewhere around 400watts. That should work quite well, and probably require
sunglasses while chlorinating.
Initial setup, minus hoses. 2nd run gas dryer was omitted and only wash bottle used.
Reaction vessel, up close:
Chlorine generator setup:
Chlorine generator, closeup:
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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not_important
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Better than a metal halide lamp, which is intended to give moderately good colour rendition and thus puts out a fair amount in the green through red,
would be a plain uncoated (clear) mercury lamp. These have peaks at 365, 404, 436, 546, and 578 nm, mostly in the range you want, and are cheaper
than metal halide.
http://www.neon-lighting.com/articles/Types%20of%20Lamps.htm
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