HOTPLATE
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GRIGNARDIMINE
I need more details on the addition of acetaldehyde and methylamine hcl to a grignard.Is it correct that you can add the methylamine hcl directly
without first making it into gas,and what is the correct order as I have read that there are quite a few problems if it is not done correctly.Also
besides heat what else would you see and after the ether+ hcl and Naoh what should the layers look like.Are there any pictures available.If I have
missed something on this or any site that can answer my question sorry.
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smuv
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No!
You must make the imine first between acetaldehyde and methylamine, isolate it and make sure it is rigorously dry and then alkylate/reduce it with the
grignard. Methylamine HCl is an acid, it has 2 readily extractable protons and will kill 2-eq of your grignard reagent.
Search around on the web, I am sure this has been covered somewhere. Maybe search 'grignard schiff base'
"Titanium tetrachloride…You sly temptress." --Walter Bishop
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Sauron
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Impossible to reply intelligently unless you provide proper and complete/correct citations to the references from which you draw this procedure. You
have not identified target product. You have not even said what Grignard reagent you are using. There is no single Grignard reagent, there are
thousands of them of general formula RMgX where R is a carbon compound and X is Cl, Br or I. Solvent is usually Et2O or THF and solvent and appartatus
ought to be scrupulously dry. The reaction should be closed off from the atmosphere with drying tube or bubbler (Hg or mineral oil).
So whose procedure is this and what does the paper or book state?
Sic gorgeamus a los subjectatus nunc.
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stoichiometric_steve
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Check out "Easier Grignard to Meth" in the Rhodium archives, that's most likely what he's referring to. I think Nicodem stated some time ago that
acetaldehyde and methylamine form a trimer.
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Nicodem
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I also stated to post questions without providing references, or without properly describing the topic, only in the Beginnings section where I'm
moving this thread which is an excellent example on how not to start a thread. I guess it should go to Detritus, but I'll let it be for now.
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HOTPLATE
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Sorry,I thought people might recognise the reference to the procedure,anyway here it is.My appologies for my mistakes.I will try harder in future.
Well, I think I got it all together, since no-one seems to have done this not-me thinks he will boldly go where no bee has gone before. This will be
done on the following scale: 2.025g Mg covered in 8.325ml. ether, the stirrer will be started and 3.125ml. of a mixture of 10.5375ml. benzyl chloride
dissolved in 41.663ml. ether will be dripped in and left for 30 min. until the reaction starts. The remainder will be dripped in over a 30 min.
period. The reaction temp. will be kept as close to 45°C as possible by immersion in an ice bath. After the reaction has subsided it will be refluxed
for 15-30 min. on non-explosion proof hotplate. Immediately following 5.5g of methylamine HCl and 5.5g of acetaldehyde dissolved in 61ml of ether
chilled to 0°C will be slowly added dropwise over 30 min. After the reaction has stopped the temp. will be allowed to rise to approx. 50°C and will
be refluxed for 1-1.5 hrs the temp will again be allowed to rise to approx 55-60°C and distilled for approx. 2.5-3hrs. to ensure all the solvent has
been distilled off. After this has ended 25ml. of ether in 100ml of 10% HCl will be poured into the flask. The ether will be distilled off and 25%
NaOH will be added to the flask until a pH of 10 is reached. The contents of the flask will be poured into a 250ml. sep. funnel and extracted with
2x25 ml. portions of DCM.
The extracts will be combined in a 250ml. flask and saturated with dry HCl generated from dripping HCl onto non iodinized salt, the gas will pass thru
a dreschel bottle fitted with a med. bubbler and containing sulfuric acid and will pass into the 250ml. flask containing the extracts. The precipitate
will be recrystallized from dry 2-propanol and xylene.
On the old reference I have it has the formula
Acetaldehyde + methylamine = acetaldehyde methylamine + water
Benzyl chloride+ magnesium = benzylmagnesium chloride
What about the water?
any help appreciated and solvent would be thf.
[Edited on by HOTPLATE]
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Sauron
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You just can't take a hint, can you?
Nobody is going to give you Five E-Z Lessons in How to Cook Meth.
Sic gorgeamus a los subjectatus nunc.
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UnintentionalChaos
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| Quote: | Originally posted by HOTPLATE
Sorry,I thought people might recognise the reference to the procedure |
Yes, because you assumed this was a forum for cooks. It is not.
Is "not-me" the new swim over in methland?
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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smuv
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| Quote: | | Immediately following 5.5g of methylamine HCl and 5.5g of acetaldehyde dissolved in 61ml of ether chilled to 0°C will be slowly added dropwise over
30 min. |
Good luck making toluene on your 'non-explosion proof hotplate.'
"Titanium tetrachloride…You sly temptress." --Walter Bishop
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harrydrez
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I hate reading posts like this, it's not so much the fact that they don't know what they're doing (no one knows everything), it's that they don't
really even care. They just want their damm meth  .
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