Author Topic: Questions about drone's enolate p2p synth  (Read 7811 times)

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ning

  • Guest
Questions about drone's enolate p2p synth
« on: August 23, 2003, 12:14:00 AM »
I was reading Drone #347's acetone enolate synth, and something bugged me. He talks about fusing chlorobenzene (actually halobenzene) and acetone, by using sodium ethoxide to steal a proton from the acetone. All fine and good--I assume everything will combine out and give sodium chloride and ethanol or whatever. Only problem is, as far as I can tell, chloro(halo)benzene and acetone are this:
 
C6H5-Cl + CH3-CO-CH3 + NaEtO

which would combine to give

C6H5-CH2-CO-CH3 + NaCl + EtOH

but isn't P2P actually

C6H5-CH2-CH2-CO-CH3
?

If this is the case, then in drone's synthesis, benzyl halide, and not halobenzene would be called for. Or am I missing some mysterious carbon-hydrogen source?

Also, what would you(all) say to the possibility of reacting chloroacetone with benzyl chloride, either directly producing Cl2, or by adding metallic sodium to the mixture to rip the chlorines out?

Thanks for the help...

ning

  • Guest
Wait!
« Reply #1 on: August 23, 2003, 12:20:00 AM »
I just realized I am a moron, and that Drone is right...
Same number of carbons. But my other question still stands-
just change it to be chlorobenzene.

:-[

Rhodium

  • Guest
chloroacetone + chlorobenzene + sodium
« Reply #2 on: August 23, 2003, 03:49:00 AM »
Very few reactions produce Cl2 gas just like that, especially not if you react two alkyl chlorides with each other. Nothing would happen.

If you would add sodium, a lot of things would happen (possibly with explosive force). Very roughly speaking, the sodium would rip off the chlorines from the chloroacetone and chlorobenzene and then all the formed fragments would all add with each other in a big mess, and not at all as nicely as one benzene and one acetone fragment joining together to form P2P.

Search the web for "Wurtz Coupling" (the name for such metal-mediated connection of alkyl halides) and you'll see that the reaction most often is too uncontrollable to be of any use when making as complicated molecules as P2P, it is mostly only useful when forming certain hydrocarbons.

ning

  • Guest
Hmmm....Thanks
« Reply #3 on: August 23, 2003, 07:06:00 PM »
So I guess the big question is how to produce sodium electrolytically. Any pointers?

I read on a mining web page a method to produce sodium amalgam, by performing electrolysis of NaOH with a mercury electrode, which would force the sodium into the mercury.
They used it to reduce precious metal oxides so the mercury could suck them up, but I keep wondering if something this easy could be done to produce alkoxides. Perhaps like this?

A beaker is filled with ethanol, NaOH, and dessicant. Electrolysis is performed, with this result:
            (e)
NaOH + EtOH --> NaOEt + H2O

which would probably just switch right back again, except the dessicant absorbs the water before it can get back to the alkoxide. When the pot is nice and yellow, the alcohol is removed and evaporated to deliver a nice alkoxide for use in the next step.

I don't know much electrochemistry. Could it work?

Thanks again for taking the trouble....

acid_egg

  • Guest
alkali alkoxides
« Reply #4 on: August 23, 2003, 08:12:00 PM »
Alkoxides..easy. :)

Post 257912

(Antoncho: "Alkali metal alkoxides: finally, OTC!", Novel Discourse)

Post 236718 (missing)

(foxy2: "Sodium methoxide from MeOH, NaOH, butanol!!!", Chemistry Discourse)

Rhodium

  • Guest
Sodium = bad idea
« Reply #5 on: August 23, 2003, 11:26:00 PM »
Ning: I just told you that the sodium idea would NOT be suitable, as it wouldn't produce P2P, but rather a big mess.

acid_egg

  • Guest
Rhodium, isn't he musing on routes to sodium...
« Reply #6 on: August 23, 2003, 11:42:00 PM »
Rhodium, isn't he musing on routes to sodium alkoxides (well ethoxide specifically)?

ning

  • Guest
Sweet!
« Reply #7 on: August 23, 2003, 11:44:00 PM »
Looks like the dehydration idea wasn't too far off! Ass-kicking good! I won't forget that. All that must be done is to find a decent source of halobenzene and....

Alkoxides seem very useful for all sorts of C-C bonding uses, and if they are that easy to make...

So, then...here's a question--what keeps the acetones from condensing by themselves? Isn't the aldol just like this? Or is it that the halobenzenes are just so much more attractive?

Thanks, that was a good catch there. I have some hope now.

java

  • Guest
Re:"Questions about drone's enolate..
« Reply #8 on: August 24, 2003, 04:32:00 PM »
Try reading these links , as to enolates and other possibilies  and solvent to use for making the enolates...java

Post 309640

(java: "easy ketone.ArCH2COCH3", Chemistry Discourse)


Post 451983

(Rhodium: "Potassium tert-Butoxide in Organic Chemistry", Chemicals & Equipment)


Edit: some links not relevant removed by java


ning

  • Guest
Thanks, java
« Reply #9 on: August 24, 2003, 06:10:00 PM »
More good links!
Well, I was sort of thinking that solvent was unnecesary, since the reactants (acetone and chlorobenzene), and the product (p2p) were all liquid. As for the alkoxide formation, if I made ethoxide, it would just be in ethanol, I suppose, cuz that's its ion, right? I mean, like Na.OH in H.OH, Na.OEt in H.OEt sounds ok to me...No reason to seperate if they work together, and the reaction ends up producing EtOH anyway, right? I'm sure I would have to dry the acetone, of course. Maybe the whole shebang could be semi-one-pot? Naahhh...I must be dreaming.

java

  • Guest
Re:"Questions about drone's enolate..
« Reply #10 on: August 24, 2003, 11:00:00 PM »
Here is another point of looking at it.....java

Post 397557 (missing)

(Rhodium: "Process For Producing Benzyl Ketones", Stimulants)


Post 395155 (missing)

(pHarmacist: "iodobenzene 86–87% yield", Chemistry Discourse)


Post 391612

(pHarmacist: "Synthesis of Iodobenzene/Chlorobenzene in one pot", Methods Discourse)


Post 350684 (missing)

(Rhodium: "Half-a-Pint - RIP", General Discourse)
    .....there is a pearl in the narrative of this post , so read it all


ning

  • Guest
whoa...
« Reply #11 on: August 25, 2003, 05:13:00 AM »
blowing me away there...I read half-a-pint's last post before, but I didn't see that p2p stuff...
Seems there is 2 pathways he is talking about:

1: benzaldehyde "somehow" gets turned into benzyl cyanide(or was it benzonitrile?), which then is converted to alpha-acetoacetonitrile, which is somehow changed into p2p with sulfuric acid. Sounded easy, but there are some deep holes my chemistry can't cross yet.

2: Benzoic acid + perborate --> perbenzoic acid --> Iodo/Bromobenzene, to be substituted into the drone synthesis, I suppose.

I want to see totally OTC p2p. If half-a-pint is right in what he's talking about, seems like a good chance of it.

thanks... :)

java

  • Guest
P2P via acetone enolate.......
« Reply #12 on: December 05, 2003, 01:40:00 AM »
As I never really lost interest in this method of producing P2P I have read on and found this to be of interest.......

Post 122752

(dormouse: "what happened to my enolate review?! -drone 342", Serious Chemistry)

Drone 342, provides some excellent reference review and provides many leads to this inexpesive and easy method to produce this ketone.

Addendum:

This other article talks about the use of sodium , as you seem fixed on using it in developing your research on this interesting method.....java

http://www.basf.com/inorganics/pdf/bulletin/KTB%20bulletin%207-3-01.pdf



Note  Edited :thanks to Rhodium , I made the link direct to the Pdf file....java