Bender84
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Nitrous acid scavenger
I would like to conduct a trial nitration of 2-EH using a nitrating mixture made from mixed acids and spent acid. At the same time, I would like to
see how (if at all) the addition of approximately 1% urea (which will act as a nitrous acid scavenger) do the mixture affects the process itself and
whether the resulting product differs in any way from the product obtained in the reaction without the use of urea.
However, I am wondering if adding urea to the nitrating mixture poses a risk of creating nitrourea, which is something I would prefer to avoid. Or
there's nothing to worry about?
Thanks in advance.
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Fery
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I do not know what is 2-EH but small amount of nitrous acid could catalytically speed up some nitrations (that's the reason why spent acid is added).
Please post your results with and without the scavenger. If it has an impact then the beginning of the nitration should be delayed.
HNO2 will be very likely formed during your nitration which should decompose all the urea as you use only approx 1% of it.
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Bender84
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Thanks Fery.
2-EH stands for 2-ethylhexanol. The intended product of the reaction is 2-ethylhexyl nitrate. The reaction is essentially instantaneous, yet sometimes
I obtain a product with a yellow color, slightly acidic, and I cannot identify the cause of the problem. 2-EH from different manufacturers yields
different results. The desired product is colorless and has an acidity of <3 g KOH/100 ml. The yellow one has an acidity of around 6-7 and higher.
I want to see if the addition of urea, as a scavenger for HNO2, will make a difference, but I would like to avoid the synthesis of nitrourea, which is
an explosive material.
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Fery
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Aha, the HNO2 catalyzes nitration of some aromatic which I cannot remember from my head. For the alcohol the HNO2 is maybe not necessary as a catalyst
and the reaction will very likely run without traces of HNO2. You are going to prepare nitroester of the alcohol (alcohol-OH -> alcohol-O-NO2).
There could be some side reaction by oxidation of the alcohol with HNO3 and thus producing HNO2. HNO2 may react with alcohol into nitrite
(alcohol-O-NO).
Nitrourea is explosive when concentrated/crystalline and if you even have only traces of nitrourea in you product then no explosive properties at all.
Nitroalcohols explosives are like glycerol trinitrate or ethylenglycol dinitrate or nitrated cellulose or nitrated xylitol etc. So not nitroesters of
alcohols with only one -OH group.
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