kafka
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o-Toluidine from xylene
o-toluidine seems easy enough to make from toluene (via nitrotoluene) but toluene is imposibble to buy locally around here. So im looking at other
options. i have acess to xylene wich is so damn similar to o-toluidine. ive looked around a little and found some exotic methods for mononitration of
xylene but nothing to easy. im sure im missing something obvious. any ideas?
If a straight mononitration of xylene (the correct isomer of course) is not possible, are there any tried and true methods of making tolulene from
xylene? how about toluene from benzene? xylene to benzene is easy enough...
thanks for the advice. since o-toluidine is such an interesting chemical, and xylene so available, id love to do a write up with pictures.
[Edited on 27-11-2006 by kafka]
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not_important
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First off you'll be dealing with the mixed xylenes. You can isolate them, but it is a bit of work.
After that oxidising one of the methyl groups to the carboxylic acid, take that to the amide, and Hoffman rearrangement to get the amine, should be a
fairly easy route.
.....................
Mononitration isn't too hard, but you'll have some polynitro xylenes as well. Fractional distillation will isolate the mononitro ones. Use excess
xylene, fairly mild nitration conditions. Don't have them handy, but there are references and examples around.
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Pabpa
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o-xylene -> o-toluic acid:
http://www.orgsyn.org/orgsyn/orgsyn/prepcontent.asp?print=1&...
toluic acid -> toluamide
pat. DE869639
toluamide -> toluidine
http://www.erowid.org/archive/rhodium/chemistry/methylamine....
---
nitration of o-xylene:
Kobe/Pritchett, Ind. eng. Chem. 44, 1398 (1952)
55% 3-nitro-1,2-xylene (bp: 136°C@38mbar)
45% 4-nitro-1,2-xylene (bp: 143°C@28mbar)
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kafka
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The mentioned routes are quite interesting. Im leaning more twords the possiblity of making toluene from xylene then nitrating that. I cant figure out
how to go from xylene to toulene. It looks so simple, wich angers me even more. making benzene from xylene still seems easy enough so im keeping that
in mind. Some ideas ive had is the partial hydrogenation of xylene to tolulene and haloBenzene to tolulene via methylation.
im having problems finding information on the methylation of halobenzene. would something like methyl chloride and iodobenzene or bromobenzene work
here?
thanks everyone for the help. im trying to find the awnsers myself but im having problems
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not_important
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You can get benzene but not toluene?
The main routes from xylene to toluene are
o refluxing with AlCl3, AlBr3, or simillar, and slowly fractionating off the toluene from the xylene+polymethylbenezes. You need a good fractionating
column for this.
o Oxidation of one of the methyl groups, then decarboxylation to toluene. The oxidation can be done using a number of methodes, the decarb isn't very
efficient.
Benzene can be done the same way, adjust the fractionation step to return toluene to the pot and only pass benzene.
One other alternative is to mononitrate xylene, oxidize one methyl, and decarbox that which will go better, and fractionally distill the mixed
nitrotoluenes.
I still think that the xylene to toluic acid to amide to amine route is the best. You can remove m-xylene by shaking with moderately strong H2SO4,
don't remember the exact conditions but not hard to find, and wash with water to remove the sulfonated m-xylene. Then cool the remaining xylenes to
fractionally freeze out the p-xylene to get fairly pure o-xylene. Oxidise one methyl and so on. You can make the amide by forming the ammonium salt,
and heating that in a slow stream of NH3, not much of a stream really more of an NH3 atmosphere.
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Pabpa
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| Quote: | | I still think that the xylene to toluic acid to amide to amine route is the best. |
Yepp
| Quote: | | You can remove m-xylene by shaking with moderately strong H2SO4, don't remember the exact conditions but not hard to find, and wash with water to
remove the sulfonated m-xylene. |
Jacobsen, B. 10, 1009
But you don't have to remove the m-xylene. It won't be oxidized by weak nitric acid. Start with o/p/m-xylene and you'll get o/p-toluic acid. All you
have to do is separating o/p-toluidine in the last step with oxalic acid. (Brimmeyer, Z. 1865, 513)
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kafka
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Im loving the feedback from you two! The oxidation can be done with KMNO4, wonderful, easy to find stuff. seperation of the isomers with oxalic acid.
Then concentrated ammonia and a NH3 atmosphere to get teh amide. From there a hoffman rearangment with NaOH and Br2 in H2O should give the desired
product.
yup thats the method for me. I dont care much about the amount of work envolved, i just want it all otc so other experimenters can try it as well.
to awnser the question about benzene, i dont have access to it, i can make it, theres a nice thread on that going. i can order tolulene but i really
rather go to the hardware store as would most people who are tryign to make this substance.
of course this is all for noveltys sake, nothing illegal will be preformed by myself.
thanks for teh help, i will start looking up detailed reactions, ill post what i find concerning what should be doen to perform each reaction in
detail (ie wieghts etc), constructive critisism is much appreciated.
sorry about the messy reply, im late for class!
btw, how about methylation of aniline?
[Edited on 29-11-2006 by kafka]
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not_important
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| Quote: | Originally posted by kafka
btw, how about methylation of aniline?
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To toluidines - not real easy, the NH2 complexes with and inactivates many catalysts, and tars are common products. For olefins aniline with some
active aluminium to form aluminium anilide works like F-C for non-activated aromatics.
http://www3.interscience.wiley.com/cgi-bin/abstract/10957482...
N-methyl aniline - aniline plus methanol and hydrochloric acid heated under pressure. Amd old industrial process.
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kafka
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"N-methyl aniline - aniline plus methanol and hydrochloric acid heated under pressure. Amd old industrial process."
THis is the reaction that i had read right before i wrote my last reply. IT sounds interesting, im looking for more data on it. i believe the temp is
around 230 C which isnt that bad, only problem im having is thinking of a good reaction vessel. Im guessing galvanized pipe, or copper would mess with
the reaction soo much.
Maybe i should rename this thread o-toluidine, since we are discussing routes other than from xylene.
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kafka
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ahh sorry for all the questions (just starting to cover aromatic reactions in class right now), how do i ensure that only one methyl group gets
oxidised? is there a "poison" (like for catalyst) or somethign that should be used or just cooler temperatures?
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Pabpa
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| Quote: | | IT sounds interesting, im looking for more data on it. |
http://en.wikipedia.org/wiki/Hofmann-Martius_rearrangement
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