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kafka
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[*] posted on 13-4-2007 at 13:57
washing layers with KOH

hello, quick question:

if one were to make mononitro toluene via the usual method (H2so4 +HNO3 + toluene) would there bay any reason not to wash the product of that reaction with KOH? the methods i have seen mention washing it with an aquesous solution of NaOH but KOH is currently on hand and NaOH is not. Any chance harming the nitrotoluenes produced?

thank you for your help,

kafka
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Bromine
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[*] posted on 13-4-2007 at 22:33


I think you could use KOH solution.



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UnintentionalChaos
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[*] posted on 13-4-2007 at 23:15


Potassium behaves much the same as sodium, especially for this kind of use. You can use washing soda or baking soda as well for washing the MNT. All you need is something alkaline to neutralize excess acid.



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kafka
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[*] posted on 14-4-2007 at 10:41


thanks, i assumed there would be no problem with the KOH and the obvious method using baking soda totally escaped me. thanks for the help.
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chemrox
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[*] posted on 14-4-2007 at 21:50


KOH is expensive compared with Na2CO3, NaHCO3 and NaOH (Red Devil Lye). Don't waste your KOH this way.
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[*] posted on 15-4-2007 at 00:52


Alkali is not compatible with nitroaromatics. There will be some reaction taking place, producing nitrocresols from your nitrotoluenes. Caustic alkali is not suitable as a drying agent for nitrocompounds, and not for washing them either.
Wash with NaHCO3 or with Na2CO3, but not with strong alkali, you will degrade your product.



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[*] posted on 15-4-2007 at 00:54


Hydroxydes are basic enough to deprotonate o- and p-nitrotoluene. They actually dissolve in aq. NaOH or KOH giving an intense dark yellow solution.
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