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Ramiel
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A few other options are discussed here:
<html><a href="http://www.sciencemadness.org/talk/viewthread.php?tid=132">Methanol=>Methanal</a></html>
I'd be interested to know about the reaction involving a 'hot' solution of acetone and 'bleach'. Unfortunately I'm away
from my chemicals at the moment, and can't check. Just imagining it in my mind it seems to work out sochiometrically.
<html><img src="http://www.sciencemadness.org/scipics/FormBAc.gif"></html>
ps. Formaldehyde & Paraformaldehyde are nasty; truly evil. Just a tiny whiff knocked me on the floor for half an hour, it was agony.
- Ramiel
Caveat Orator
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ziqquratu
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This won't work, I dont think. First of all, your equation is unbalanced - you have two hydrogens too many...
Second, this is a classic case of the Haloform reaction. The hydrogens on carbons directly adjacent to the carbonyl (ie. the alpha-hydrogens) are
made acidic by the electron withdrawing properties of the carbonyl group. Thus they are easily substituted by chloride (which is very electron-rich),
to give chloroform. If you use three equivalents of NaOCl you get chloroform and sodium acetate; six equivalents of hypochloride gives two
equivalents of chloroform and one of either carbon dioxide or sodium formate (I'm can't remember which of the two it is - it may depend on
the conditions). Anyway, any formaldehyde that was formed (and there is none formed at any point in the reaction, but I'm including this to make
the point) would be immediately oxidised to either the formate or to carbon dioxide. Hence, this is not the way to get it.
[Edited on 17-6-2003 by ziqquratu]
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Organikum
resurrected
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Yep. Makes chloroform.
I believe this to be the right equatation:
CH3COCH3 + 6 NaOCl -> CHCl3 + NaCH3COO + 2 NaOH + 3 NaCl
It is the most easy synth in organics I know and yields chloroform. Useful for kidnapping daughters of milionares or for washing
dimethylaminehydrochloride out of methylaminehydrochloride. 
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frogfot
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decarboxylation...
I have checked the preparation of formaldehyde in scimadness library and one thing sounds strange.. reaction is carried out in a glass flask?
This adress tells us that decomp. temp. of Ca formate is >400*C
www.baoyuanchem.com/product.html
Is it ok for a glass vessel? Was this method tested, or maby they lie about so high temp?
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a123x
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I didn't think this was worth starting a new thread for and it seems to fit here. I want to try producing formic acid(to react with Ca(OH)2 to
make calcium formate to make formaldehyde... to react with ammonia to make hexamine). I found a vague procedure while searching google and wanted to
know whether it would work or not. It was 4 parts glycerin, to 4 parts oxalic acid, and one part water. Heated at 100C for 12 hours. Mixed then with
it's weight of water, then distilled to get formic acid. I was just wondering if that is indeed a workable procedure for producing formic acid.
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a123x
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I was just thinking, what about oxidizing methanol with ozone? Just bubbling ozone directly into methanol from a HV ozone generator? I guess maybe it
wouldn't be practical but I'm just wondering if it is possible.
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ziqquratu
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Hey a123x, check out http://www.rhodium.ws/chemistry/formic.acid.html
This procedure uses oxalic acid and glycerine to produce decent yeild of formic acid. You use anhydrous glycerol, however, so I'd be a little
wary about the synth you saw that required water. Some water is required for the reaction, as I understand it, but you get enough from the oxalic acid
and the condensation with the glycerine. The byproduct of the reaction is allyl alcohol, which can be a useful organic solvent for some reactions,
and a useful reagent in some organic syntheses.
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a123x
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Thanks but I think I'll just go with the oxidation of methanol for obtaining formaldehyde and formic acid since if I'm not mistaken using
H2O2 should likely produce formaldehyde from methanol but also oxidize some to being formic acid as mentioned earlier in this thread so I guess it
works for me either way.
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