PrimoPyro (Change my Title Back!)
04-19-02 00:26
No 299045
      Aminomercuration Questions  Bookmark   

Hi! smile

Once again, I call upon the knowledge of those more advanced than myself, to answer some rather simple questions. Thanks to anyone who reads this and replies. smile

At the bottom entry of ../rhodium/chemistry /aminomercuration.txt Osmium states:

2-acetamidohexane [N-(2-hexyl)acetamid]

To a ice-cooled solution of 64.8g (0.20mol) of Hg(NO3)2 in 100ml MeCN
16.8g (0.20mol) of 1-hexene are slowly added keeping the temp below 30C.
The clear yellow solution is stirred for 1hr at RT. With ice-cooling 200ml
3N NaOH are added, followed by a solution of 3.80g (0.10mol) of NaBH4 in
200ml 3N NaOH. Again stir for another hour. Decant the aq/organic layer
leaving the elemental Hg behind, saturate the aq. layer with NaCl and
extract with Et2O (2*100ml). The extracts are dried with Na2SO4, the
solvent removed and the residue distilled. 22.8g (80%) amide, bp (1.6 torr)
93-96C.


Am I correct in thinking that the acetonitrile is both a solvent for the reactants hexene and mercuric nitrate, and that it is also a reactant, acting as the amine source for the amide?

RCH=CH2 + CH3CN ==Hg(NO2)2/H2==> RCH(NHCOCH3)CH3 correct?

The acetonitrile adds to the olefin and is oxidized to the carboxylate, which because of the nitrogen, is an amide. So the mercuric nitrate is a catalyst, correct?

If so, can other mercuric compounds be substituted for the nitrate, or do yields suffer?

Is my understanding of this reaction correct?

I'm interested in the obvious possibility of using safrole to jump to MDA-acetamide.

                                                    PrimoPyro

Vivent Longtemps La Ruche!
 
 
 
 
    Rhodium
(Chief Bee)
04-19-02 00:53
No 299046
      Aminomercuration  Bookmark   

Part of it is answered in the same text, perhaps a little cryptic:


- nature of the anion on Hg is important

 HgCl2 > Hg(OAc)2 > Hg(NO3)2 = Hg(ClO4)2

-the reaction has an IONIC character:

first a pi-complex between the olefin and the mercury salt is formed, then the amine adds to give the Markovnikoff addition product

- - -

The paper also indicates that "In all cases, rapid formation of amine-mercurcy complexes was observed prior to the addition of the olefin substrate. The rate of aminomercuration proved to be a sensitive function of the mercuric salt employed."



Here they state that the nitrate is equivalent in effiacy to only the perchlorate, the acetate and nitrate is inferior. It must also be present in a stoichiometrical amount.

Yes, in this particular example the acetonitrile itself works as a nucleophile towards the intermediate mercurinium complex (as in a three-membered ring incorporating a positively charged mercury ion).

Almost anything can be used as a nucleophile in the addition - I have personally seen oxymercuration, nitromercuration, aminomercuration and amidomercuration in the literature, probably many more is possible.

Here is an illustrated example of amidomercuration:

../rhodium/chemistry /allylamination.html

And some more on mercuration of safrole:

../rhodium/chemistry /mercury.html

Hmm... Time to collect them all into an enviro-unfriendly writeup?
 
 
 
 
    PrimoPyro
(Change my Title Back!)
04-19-02 12:26
No 299197
      Thank You Rhodium  Bookmark   

As you know, this is for info purposes only of course.

I can assure you that SWIPP is very environmentally conscious, and would never attempt such a reaction with the intent to dump waste materials into the environment. I've studied foxy2's mercury decontamination thread carefully.

If this were ever attempted, SWIPP would reduce all salts back into elemental mercury, followed by triple distillation to regain purity of the mercury. Leftover residues would be contained in a vessel and stored, adding to them over time as more reactions produce more wastes, until there was sufficient amount to be taken to a licenced chemical waste processing site, and SWIPP would pay the needed price to have the wastes properly dealt with by a professional.

And as for the distillation, it would be done in a *purchased* mercury distillation apparatus, not a homemade one.

SWIPP is interested because of the near 1.8Kg elemental mercury in his posession without an apparant use other than for Al/Hg amalgamations. That's a lot of amalgamations!

I have not yet viewed your links, I will after submitting this. tongue So if one used N-methylformamide in this procedure, it would attach to the olefin to create the MDMA-formamide, which could be hydrolyzed to MDMA? This would be pretty cool if it's the case, because it would be akin to a Leukart product, but without the need to shange the safrole into MDP2P.

                                                    PrimoPyro

Vivent Longtemps La Ruche!
 
 
 
 
    terbium
(Old P2P Cook)
04-19-02 14:43
No 299270
      Anhydrous mercuric nitrate.  Bookmark   

To a ice-cooled solution of 64.8g (0.20mol) of Hg(NO3)2 in 100ml MeCN
I wonder how one obtains the anhydrous mercuric nitrate? Is it really as easy as drying in vacuo over P2O5 as stated in ../rhodium/chemistry /allylamination.html? To produce anhydrous ferric nitrate requires baking the hydrated salt in a stream of nitric oxide.
 
 
 
 
    Rhodium
(Chief Bee)
04-19-02 15:54
No 299293
      mercuric nitrate  Bookmark   

I remember heated discussions on that topic from earlier days - apparently mercuric nitrate is very sensitive to heat and decomposes at pretty low temperature, so only  vacuum/dehydration is allowed, no heating.