wg48temp9
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Aurin- tricarboxylate synthesis
In the synth of Aurin- tricarboxylate in the fllowing note what is the purpose of the nitrite?
"Add 4 g of sodium nitrite, in small portions and while vigorously
stirring, to 44 ml of sulfuric acid (sp gr 1.84) contained in a 250-ml
beaker. The nitrite should be added slowly to prevent excessive
evolution of oxides of nitrogen. When all of the nitrite is dissolved,
cool the solution to 10° C. Over a period of 5 to 10 minutes, next add
12 g of salicylic acid, while again stiring the solution.
Cool the solution to 3° C by immersing the beaker in crushed ice,
and add drop wise 3.5 ml of an approximately 37-percent solution
of formaldehyde, while again vigorously stirring.
Since the temperature at this stage must not exceed 5° C
a small thermometer makes a convenient stirrer.
When all the aldehyde has been added, allow the beaker to remain in
the ice bath for about 1 hour and stir the contents every 5 minutes.
The reaction is now allowed to proceed at a reduced temperature for
about 20 hours. A cooling bath is conveniently made by placing a
20-lb block of ice in a tray having approximately the dimensions
12 by 12 by 3.5 inches and filling the tray with ice water. With this
arrangement, when the room temperature is 20 to 25° C,
the temperature of the reacting mixture will increase about 1 to 2° C
during the first 7 hours and then gradually to about 20° C during the next 13 hours."
From Attachment: prep-aurintricarboxylate-jresv21n1p113_A1b.pdf (2.7MB)
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I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Boffis
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If you read your own attached paper you will see that they state that the course of the reaction isn't certain but its possible that some of the
salicylic acid is converted into a nitroso compound and this condenses with the the first formed methylenedisalicylic acid (assuming it is first
formed!).
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wg48temp9
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Quote: Originally posted by Boffis  | | If you read your own attached paper you will see that they state that the course of the reaction isn't certain but its possible that some of the
salicylic acid is converted into a nitroso compound and this condenses with the the first formed methylenedisalicylic acid (assuming it is first
formed!). |
Thanks Boffis I missed that.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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wg48temp9
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I found a curious note titled:
SYNTHESIS OF THE COVALENT HYDRATE OF THE INCORRECTLY
ASSUMED STRUCTURE OF AURINTRICARBOXYLIC ACID (ATA)
Attachment: cushman1990.pdf (566kB)
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The note suggests that the usual synthesis using salicyclic acid, formaldehyde, sulfuric acid and sodium nitrite produces a polymer of methylene
linked aurincarboxylic acid molecules. Its not helpful in understanding what the nitrite does but it does explain the use of
3,3'-dicarboxy-4,4'-dihydroxydiphenylmethane (two molecules of salicyclic acid linked with methylene) in the synthesis of aurincarboxylic acid as
described in Org. Synth. 1929, 9, 8 DOI: 10.15227/orgsyn.009.0008.
Attachment: CV1P0054.pdf (337kB)
This file has been downloaded 188 times
[Edited on 15-8-2019 by wg48temp9]
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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