Crowfjord
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2-(4-hydroxy-3-methoxy-phenyl)-nitroethene/Vanillin nitrostyrene
The nitrosyrene resulting from condensation of vanillin (4-hydroxy-3-methoxy-benzaldehyde) and nitromethane was prepared in modest yield (54% based
on vanillin. This is a fairly easy synthesis with great aesthetic appeal, and in my opinion would make a great experiment for those just beginning in
organic chemistry, provided the materials can be acquired (probably the most difficult part). The product also can function as an acid/base
indicator1.
10 g vanillin, 3.4 mL* nitromethane, and just enough methanol (MeOH) to dissolve all vanillin (~10 mL) were added to a half-pint canning jar and
swirled to mix. The jar was placed on a scale which was tared, and 0.50 g n-butylamine was added. The solution immediately turned yellow, then
quickly to red. The jar was capped and swirled again to ensure proper mixing (pic 1).
After sitting at ambient temperature for about 1-2 hours the solution had turned to a solid red mass (pic 2). This was broken up, 5 mL MeOH added,
then vacuum filtered on a Buchner funnel, washing with 0.1 M HCl, ~100 mL. This caused a change in color from red to bright yellow (pic 3).
The damp yellow solids were recrystallized from hot (almost boiling) MeOH (~150 mL) - the solids were dissolved in the hot MeOH with stirring, the
jar capped and allowed to come to ambient temperature, then placed in the freezer overnight. The fibrous, cotton-like crystals were vacuum filtered,
washing with cold 0.1 M HCl, then with cold distilled water. The air-dried product weighed 7.0 g (54%)(pic 4).
This is a nice, quick and fun preparation - one could probably go from start to finish in a few hours. The colors are fantastic! I have another
batch going, prepared the same as above, but with 2 molar equivalents of nitromethane (as in the reference) this time, and acidification of the
resulting mass before filtering (and hopefully less messy technique  ). Maybe
these changes will provide a higher yield.
1. Can J Res. 1948 Jan;26(Sect B 1):7-10.
DOI: 10.1139/cjr48b-003
* This was a miscalculation/misread. I intended to use 1.1 mol equivalents, which would be about 3.9 mL
   
[Edited on 7-6-2014 by Crowfjord]
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plante1999
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Nice experiment, although I can easily see clandestine chemistry as an inspiration. I even wonder if the amine of the said compound is restricted or
not..
I never asked for this.
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Crowfjord
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Not really sure, but I actually chose vanillin in order to avoid making anything illegal (or a precursor to something illegal). That, and because
vanillin is so cheap. The inspiration was to make a substrate with which to test the Cu/Al reduction system, mainly. Since the prep was so simple,
with nice colors, I figured that I would make a separate thread, for the benefit of beginners.
[Edited on 7-6-2014 by Crowfjord]
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plante1999
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Keep us updated on the weird copper/aluminium reduction too. I know vanilin can be used to make MDMA and MDA but it must be processed before the
addition of the nitro compound.
The amine might enter in the amphetamine analogues legislation of Canada, better to keep away from it.
[Edited on 7-6-2014 by plante1999]
I never asked for this.
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arkoma
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so what. beautiful crawfjord.
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
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PHILOU Zrealone
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I suppose it is the trans-nitrostyrene isomer.
The use of butylamine allows one to think to the first formation of a Schiff base.
Ar-CH=O + H2N-R --> Ar-CH=N-R + H2O
Nitromethane chemistry is very special...and proportions between aldehyd and nitromethane might give a lot of various products 
2 Ar-CH=O + CH3-NO2 --> Ar-CHOH-CH(NO2)-CHOH-Ar --> Ar-CH=C(NO2)-CHOH-Ar + H2O
Ar-CH=O + 2 CH3-NO2 --> Ar-CH(CH2-NO2)2 + H2O
Also possible:
O2N-CH2-CH(-Ar)-CH(NO2)-CH(-Ar)-CH2-NO2
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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Crowfjord
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Quite true, PH Z. I will do some analytics tomorrow (melting point, TLC) to verify what I have, and assess purity.
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PHILOU Zrealone
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By the way I like your idea very much...
I will try to nitrate the resulting molecule in hope to get the 2,5-dinitro compound...split off the CH3 to free the hydroxy group and oxydise to get
the ortho-quinone molecule.
Then maybe make a polymer of the polynitrostyren.
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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Crowfjord
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The second run, as stated above was conducted exactly the same as the first, except that 7.1 mL nitromethane (~2 mol equivalents on vanillin) was
used, more care was taken to avoid spillage, and crystallization was made to happen more slowly. This resulted in slightly larger crystals, and a
total yield of 8.17 g (63%), so a small improvement over the first time. Melting point: 171-173 C, lit: 169 C (paper referenced above).
Both experiments gave only one spot on TLC (2:1 ethyl acetate:methanol), though they gave different Rf values (so did vanillin, despite using the
exact same elution mixture and the same vanillin solution). See photo.
The nitrostyrene may still be a little impure; a better solvent system probably could have been chosen.
1:run #1
V: vanillin
2: run #2
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Baffled
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Just a few papers, because there's more to the Henry than that!
Attachment: Boobalan R.; Lee G.; Chen C. Copper Complex of Aminoisoborneol Schiff Base.pdf (435kB)
This file has been downloaded 1391 times
http://www.orgsyn.org/Content/pdfs/procedures/v82p0087.pdf
Attachment: Henry.pdf (199kB)
This file has been downloaded 702 times
Attachment: Henry (1).pdf (325kB)
This file has been downloaded 814 times
[Edited on 16-6-2014 by Baffled]
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