Sciencemadness Discussion Board

Alcoholic nitrites from N2O3

Alastair - 13-7-2011 at 08:24

Hello everybody! Im kinda new here, so nice to meet ya all.

Now my question to those more intelligent than me :D

N2O3 + 2NaOH = 2NaNO2 + H2O.

I understand that lye isnt alcohol but alcohols share the OH group with it.

Could the reaction go like
2IP-OH (isopropyl) + N2O3 = 2IPNO2 + H2O ?

Pardon my ignorance... Thank you for answers!

barley81 - 13-7-2011 at 08:43

Yes, this is basically the way alkyl nitrites are made. Try Vogel's Practical Organic Chemistry http://library.sciencemadness.org/library/books/vogel_practi...
Quote from page 302:

Alkyl nitrites. By the interaction at 0° of the alcohol with sodium nitrite
in the presence of excess of concentrated sulphuric acid, for example :

C<sub>6</sub>H<sub>11</sub>OH + HONO • C<sub>5</sub>H<sub>11</sub>ONO + H<sub>2</sub>O
n-Amyl nitrite

Here's a video I found of the synthesis of isopropyl nitrite: http://www.youtube.com/watch?v=ygAxh81WaWg

Alastair - 15-7-2011 at 07:55

So could somebody use dinitrogen trioxide INSTEAD of the commonly used Sodium nitrite?

Nicodem - 15-7-2011 at 08:30

N2O3 is generally considered a nonisolable compound at room temperature, though it is an equilibrium species present in a mixture of NO and NO2 gases.
A 1 : 1 mixture of NO and NO2 introduced into isopropanol would indeed yield the ester, but this would be less practical synthesis than the general procedure described in Vogel's, because the only easy way to obtain a NO/NO2 mixture of the correct stoichiometry would be to make it from NaNO2 or other nitrites. Obviously, if NaNO2 is already available, then you can just use it in the general nitrite ester procedure without dealing with noxious gases.

Beware that the analogy of the esterification reaction with the reaction with a hydroxide makes no sense chemistry-wise.

The shorthand for isopropyl is supposed to be "iPr" or "i-Pr" (with the letter "i" in italic as it is an abbreviation of the latin prefix "iso"). Inorganic chemists will point out that organic chemists are a bunch of idiots who don't even realize that Pr stands for Praseodymium, but the organic chemists will reply that they don't give a fuck about Praseodymium anyway.

PS: Please open referenceless threads only in the Beginnings forum section, where I'm moving this.

Alastair - 15-7-2011 at 09:33

Impressive answer! I thank you Nicodem. I now feel enlightened.
Main character in my book can not by any means get NaNO2. He intends to obtain N2O3 by Fe + HNO3 and removing impurities by freezing.