Cool both solutions
Put beaker "A" in an ice bath
Add beaker "B" to beaker "A" slowly
After the reaction remove the top layer (yellow coloured) with syringe
Are their any errors in this?
Also is there any substitutes for sodium nitrite? For example: ammonium nitrite.
I don't know where to get sodium nitrite, how can I synthesise it?
After this, will the isopropyl nitrite be pure or will I have to do something with it?
Thank you for reading and sorry for the newbie questions. LanthanumK - 27-6-2011 at 14:23
Be careful with ammonium nitrite as it can be explosive (although the reaction conditions would not be conducive to an explosion).UnintentionalChaos - 27-6-2011 at 14:33
IIRC ammonium nitrite can not be isolated as a solid and is not stable in solution. Any stable nitrite salt can be used, it's only purpose is to turn
into nitrous acid in situ. There is a very large thread here already about the preparation of nitrites. In fact, a google search for "preparation of
nitrites" (without the "") returns that thread as the second hit.JonMc95 - 27-6-2011 at 14:50
I need some help with synthesising isopropyl nitrite.
So far this is what I have (written basically):
Monograph Number: 0005216
Title: Isopropyl Nitrite
CAS Registry Number: 541-42-4
CAS Name: Nitrous acid 1-methylethyl ester
Additional Names: 2-propanol nitrite; nitrous acid isopropyl ester
Molecular Formula: C3H7NO2
Molecular Weight: 89.09
Percent Composition: C 40.44%, H 7.92%, N 15.72%, O 35.92%
Line Formula: (CH3)2CHONO
Literature References: Prepd by treating isopropyl alcohol with
nitrosyl chloride: Kornblum et al., J. Am. Chem. Soc. 77, 5531
(1955); by adding concd sulfuric acid and isopropyl alcohol to
sodium nitrite: Levin, Hartung, Org. Synth. 24, 26 (1944).
Properties: Pale yellow oil. d40 0.856; d425 0.844. bp752 39-
39.5°; bp745 39-40°. nD20 1.3520.
Boiling point: bp752 39-39.5°; bp745 39-40°
Index of refraction: nD20 1.3520
Density: d40 0.856; d425 0.844
CAUTION: Can cause vasodilation with fall in blood pressure,
tachycardia, headache. Large doses can cause methemoglobinuria
with cyanosis. Severe poisoning results in shock which can end
fatally.
Use: Jet propellant.
This dobe in Collective Volume III.JonMc95 - 27-6-2011 at 17:06
Thank you for that information, can KoNO2 replace Sodium nitrite?g3ovn - 27-6-2011 at 20:58
Yes it can be replaced by KNO2, just do the math. You can use hydrochloric acid instead of sulfuric, but i personally prefer sulfuric. Just check the
temperature, and the addition rate, never let it warm too much nor add acid too fast as it will produce NOx fumes. The procedure is like this: http://www.youtube.com/watch?v=ygAxh81WaWg , wash it like the orgsyn procedure http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV2... .
I've tried this three times, with Hydrochloric once and Sulfuric twice. Yet nothing has worked so far. What the heck am I doing wrong? Etaoin Shrdlu - 11-2-2015 at 17:36
Fantastic question. What's your procedure?Hawkguy - 11-2-2015 at 19:07
I take a few grams of NaNO2, and stir it into 20 ml Hydrochloric or Sulfuric Acid [tried both]. The mix is cooled in an ice bath, and 15 ml of
Isopropanol is added. Bubbles are produced. At this point, I leave it stirring in the ice bath for about half an hour, and then the whole thing is
left to separate. This has gotten me no yields at all, and I feel like I'm making some sort of fatal flaw at some point. Crowfjord - 11-2-2015 at 19:20
The problem might be with order of addition. I made isopropyl nitrite a few years ago by adding acidic isopropanol to aqueous sodium nitrite. I think
I used this silly write-up from rhodium, which the first post of this thread copies (without the silliness). It worked just fine.
[Edited on 12-2-2015 by Crowfjord]Hawkguy - 11-2-2015 at 19:23
Wouldn't the dilute solution affect the reaction?Crowfjord - 11-2-2015 at 19:30
Like I said, it worked as advertised. I ended up with a highly volatile water-insoluble liquid that caused instant pounding headache if inhaled.
Give it a shot. If that doesn't work, then maybe your acid is too weak or your supposed nitrite is something else. Hawkguy - 13-2-2015 at 21:11
Okay so second time. I made Potassium Nitrite by melting five grams of Potassium Nitrate in a suitable crucible. 0.4 grams of Charcoal were added,
finely powdered. Gas was produced, and finally it can be concluded no more Nitrite was left to be made when the Charcoal stopped reacting in the
molten Potassium Nitrate. When dissolved and filtered/ crystallized, yellow crystals of Potassium Nitrite were collected. 20 millilitres saturated
Potassium Nitrite solution in water were cooled in the freezer. Some crystallized out. 10 millilitres Isopropanol was mixed with about 5 millilitres
concentrated Sulphuric Acid. This was cooled as well in the freezer.
When both solutions were nice and cold, I slowly added the Nitrite solution to the Alcoholic one. NOx was produced at each addition, and it was cooled
in between as heat would be generated. Bubbling of a clear gas would also follow additions. A different smell emerged, but by the time the additions
were done, no layer separation occurred. The solution did become a greenish colour though, and Potassium Sulfate precipitated as it is insoluble in
alcoholic solutions. After an hour still, and a day, no layers separated. Although I saw a bit of yellow oily tinges at the beginning (I think) at the
end, nothing was collected. This is ridiculous. What am I doing wrong?Hawkguy - 13-2-2015 at 21:13
Maybe excess 2 - Propanol dissolved the Isopropyl Nitrite?Crowfjord - 14-2-2015 at 11:02
Excess isopropanol might be the issue. Or, it may have something to do with the homemade nitrite. The NOx produced would indicate either your HONO is
decomposing before it could react, or that what you had was still mostly nitrate. It sounds like you got a small amount of ester, though it is hard to
say whether it was of nitrite or nitrate. Did you confirm the identity/purity at all of your supposed nitrite?NitratedKittens - 22-4-2015 at 08:09
