Doctor Cat
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Selectivity of piria reaction?
I'm looking for ways to sulfonate 3-chloronitrobenzene into 4-Chloro-2-nitrobenzene sulfonic acid but since it is not activated for nucleophilic
substitutions I'm left with no easy options...
EDIT: Preferably, ways that doesn't involve freaking oleum please 
how stable is a nitro group right next to a sulfonate one? and how easy (for a home set up) is to perform a piria reaction in the other isomers of
3-chloronitrobenzene?
http://www.sbioinformatics.com/design_thesis/Nitrochloro_Ben...
[Edited on 10-08-2015 by Doctor Cat]
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Nicodem
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How are you going to sulfonate 3-chloronitrobenzene? Do you have any references for such unusual claims?
Why don't you use a more rational approach instead, possibly one that actually makes sense chemically? Like for example, preparing
2,5-dichloronitrobenzene from 1,4-dichlorobenzene (reference already on the forum), then substitute the reactive 2-chloro with a sulfide (analogously
to Org. Synth.) and then oxidize to your target compound.
…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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Nicodem
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Thread Moved
27-6-2016 at 12:49 |
aga
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orgsyn.org looks like the business.
Awe, just Awe.
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Doctor Cat
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Thanks Nicodem!
Can I ask for what reference is that for the nitration of p-dichlorobenzene? and also... I am not very sure of the oxidation step... how would you
perform this? because you would be oxidizing the disulfide in this case right?
... Can you really nitrate p-dichlorobenzene with 12M HNO3 in glacial acetic acid at 10°C ?? -> http://www.chem.uiuc.edu/weborganic/arenes/Nitration/diClben...
So far the only method I've found refers to Morgan's nitration of p-DCB (which I've been having a terribly time trying to find but which basicly
seems to involve mixing 2 parts of red fuming HNO3 with concentrated H2SO4... that procedure doesn't sound very friendly to be honest...)
[Edited on 10-08-2015 by Doctor Cat]
[Edited on 10-08-2015 by Doctor Cat]
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CuReUS
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another method would be to make 3-nitroaniline-4-sulphonic acid and then diazotise the NH2 to Cl
3-nitroaniline-4-sulphonic acid could be made:-
from sulphanilic acid - http://pubs.acs.org/doi/abs/10.1021/ja01377a020
from 1,3-dinitrobenzene - http://onlinelibrary.wiley.com/doi/10.1002/cber.18960290311/...
alternatively,3-nitroaniline could be sulphonated to get 3-nitroaniline-4-sulphonic acid
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Doctor Cat
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Thanks a lot CuReUS
Sad thing that the nitration of sulphanilic acid gives just about a 30% yield...
Its the best method I've found so far though... about the nitration, does it has to be fuming nitric acid? would KNO3/H2SO4 also work?... or at least
lower acid concentrations?
If this works then I'm planing on doing a Sandmeyer reaction to get the 4-chloro-2-nitrobenzosulphonic acid... it would be the first time I do a
Sandmeyer reaction though
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CuReUS
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Although the nitration yield could be increased using Cu salts or clay catalysts, Its wise to stick to the literature method for the time being. You
could try to make the fuming nitric acid at home, but its better to buy it.
If you feel that its just not worth the trouble, 3-nitro aniline-4-sulphonic acid is available commercially.
The sandmeyer should not be problematic since diazonium salts of sulphanilic acid are much more stable than the diazonium salts of other
compounds.Diazotised sulphanilic compounds are frequently used in coupling reactions to form dyes, so it won't be difficult to find a procedure.
I found some references for the diazotisation on similar compounds
on sulphanilic acid - http://onlinelibrary.wiley.com/doi/10.1002/jlac.18761800108/...
on m-nitroaniline - http://www.sciencedirect.com/science/article/pii/S0040402010...
there is also a thread on making chlorobenzene from aniline - http://www.sciencemadness.org/talk/viewthread.php?tid=32851
and a video too - https://www.youtube.com/watch?v=GgsCLoPi24I
[Edited on 5-7-2016 by CuReUS]
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byko3y
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I'm pretty sure the main product for sulfonation of 3-chloronitrobenzene (with oleum, of course) is 2-chloro-4-nitrobenzenesulfonic acid, although,
chlorine is not a good activating group, so god only knows what you will get.
Doctor Cat, nitration of 1,4-dichlorobenzene can be easily done with a regular concentrated sulfuric acid and 90% nitric acid CCCLXXXV.—Nitration of p-dichlorobenzene.
Piria reaction is good, when you have an aniline. Oxidation of aniline to nitrobenzene is a tricky one, because you need to avoid quinone by-products.
Nitration-diazotisation of 4-chloroacetanilide might be another way, at least it seems to be possible to chlorosulfonylate 2-nitroaniline Preparation of arylsulfonyl chlorides by chlorosulfonylation of in situ generated diazonium salts using a continuous flow reactor.
[Edited on 4-7-2016 by byko3y]
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CuReUS
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I had earlier suggested buying fuming nitric acid,but after a little searching I realized that making it at home is child's play.If you have pure
KNO3 and concentrated H2SO4,fuming nitric acid is just a distillation away  . Stoichiometric quantities of both reagents are recommended for maximum yield.
https://youtu.be/2yE7v4wkuZU?t=303
[Edited on 5-7-2016 by CuReUS]
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