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Author: Subject: Azides
Thraxx
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[*] posted on 17-1-2017 at 02:37


About the IP extract + IP nitrit method.
Schema of reaction:
HS Extract (3 times) + NaOH + IP nitrite == NaN3 + Na2SO4+IPA
1/8 mol=16g + 5g + 13ml == 7,5g

Extracted was 5 h at RT ,reaction was 24 h at -5C in freezer.Precipitated was with 3 vol. of ethanol(tech.)+aceton 1:1

Pictures: 1,2,3= extraction chemicals and extraction beaker
4=extract + NaOH solution in 40 ml IPalc.
5= extract with NaOH sol + IPnitrite=reaction mixture
6= the reaction mixture after 12 h.
7= reaction mixture after 24h.
8,9,10,11=filtration and amorph product
12=giving the product in the beaker before diluting
13 =product diluted in watter,very solubile
14=precipitation with alc./aceton mix
15=precipitation after 12 h. in freezer at -5C=ZERO
Conclusion: This reaction I did 13 x.Only one of these was with yield,all other reactions produced either dark liquid or ,like this -nothing.Does somebody knew what is wrong or what to do for to have some yield?

P1.JPG - 21kB 2.JPG - 149kB P3.JPG - 22kB P4.JPG - 18kB P5.JPG - 19kB P6.JPG - 17kB P7.JPG - 18kB P8.JPG - 18kB P9.JPG - 22kB P10.JPG - 27kB P11.JPG - 26kB P12.JPG - 21kB P13.JPG - 21kB P14.JPG - 20kB P15.JPG - 19kB

[Edited on 15-10-2016 by Thraxx]

[Edited on 15-10-2016 by Thraxx]
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PHILOU Zrealone
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[*] posted on 18-1-2017 at 00:29


Quote: Originally posted by Theoretic  
Quote: Originally posted by PHILOU Zrealone  

If OH(-) eliminates nitrite from isopropyl nitrite it will be as NO2(-) and "isopropyl hydroxyde"

It won't! That's substitution you're talking about; it's not elimination. That's why I specifically said "Hydroxide E2 eliminates nitrite from IP nitrite". E2 elimination.
OH- won't displace nitrite to form isopropanol; OH- isn't a very good nucleophile and NO2 isn't a very good leaving group, with the C-N sigma* antibonding orbital at a too-high energy to react with hydroxide.
If hydroxide ever 'displaces' the nitrite, it happens by addition to the N center, then elimination of isopropoxide anion.

[Edited on 16-1-2017 by Theoretic]

Oh yes I understand now. I simply reused your "eliminates" without noticing the E2.
Yes I was speaking of substitution.
The case of nitrite esters is a hard one because into water they are extremely unstable...while they are very easily made from dilluted HONO (what is in strong opposition with most other esters that require concentrated acid and water scavenging to schift equilibrium to the right side of the reaction).
In fact the nitrous ester suffer from very easy retroconversion into the alcohol and nitrous acid...in fact as fast as it was done.
HO-N=O + Alk-OH <===> Alk-O-N=O + HO-H
The reaction is almost instantaneous and may go via several pathways:
-nitrosonium exchange with a proton form water (most probable)
-hydroxyl exchange with a nitrite anion (probably too slow)
-protonation of the alcohol, elimination of water to make carbocation and attack of the nitrite to leave a proton (probably too slow)

So nitrite esters are sensitive to base, to acid like most esters but also to neutral water; leave a nitrite ester for a few seconds into water and it has already reached decomposition/recomposition equilibrium.
This is the reason organic chemistry likes this reactant so much.
Easily done, easily collected and very reactive (fast reacting).




PH Z (PHILOU Zrealone)

"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Thraxx
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[*] posted on 18-1-2017 at 13:00


Well,but what could be the strange liquid?Hydrazine is reducing. agent.Alcohol is not possible to be reducted,but what the HNO2?Could it be reduced into HNO azanone ? And is the azanone able to react with hydrazine or alcohol?
---
If the problem is in the lability of alcohol-nitrite,then it should be added either in drops,or it should be diluted.In the old methods they have a big part of diethylether.May be this is the reason-ether is a solvent for alcohol-nitrite.
From other point of view,in Urbanski,part III.under Baryum azid is described such method,where is ading of ethylnitrite during more hours and is freezed under -15C.
May be,that the IP extract/IPnitrite method need ether. Or an dropper.



[Edited on 15-10-2016 by Thraxx]

[Edited on 15-10-2016 by Thraxx]
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PHILOU Zrealone
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[*] posted on 19-1-2017 at 09:07


Quote: Originally posted by Thraxx  
Well,but what could be the strange liquid?Hydrazine is reducing. agent.Alcohol is not possible to be reducted,but what the HNO2?Could it be reduced into HNO azanone ? And is the azanone able to react with hydrazine or alcohol?
---
If the problem is in the lability of alcohol-nitrite,then it should be added either in drops,or it should be diluted.In the old methods they have a big part of diethylether.May be this is the reason-ether is a solvent for alcohol-nitrite.
From other point of view,in Urbanski,part III.under Baryum azid is described such method,where is ading of ethylnitrite during more hours and is freezed under -15C.
May be,that the IP extract/IPnitrite method need ether. Or an dropper.

No other idea. You have the product in hand so you can do a lot of testing on it...
Smell, evaporation (crystals?), pH, burning, explosion.

You have made so much experiments with a lot of variations on the amount of reactants and procedure. Usually less ingredients is the best to avoid side reactions --> KISS method (Keep It Short and Simple).

I think the ether may help the nitrite ester to solubilize (especially into the case of less volatile nitrite esters like n-butyl nitrite) and help the alkaline azide to precipitate from the media.

[Edited on 19-1-2017 by PHILOU Zrealone]




PH Z (PHILOU Zrealone)

"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Thraxx
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[*] posted on 19-1-2017 at 22:25


For the chemistry I am lover and fucker and from this position I feel me not competent,despite of 13 bad experiences, to tell about such important method like Thiele/Stolle's method is ,that it doesnt work.I will try to look at this method in its historic developement and connections.
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