Elementary (Hive Bee)
01-18-02 23:02
No 258058
      P2P via Benzyl Sodium  Bookmark   

P2P Method Via Benzyl Sodium

Intriged by this method mentioned in Post 239660 (not existing), I have decided to try and break down what the reaction could be. This not an answer, more of a thought train that needs more input from other bees, as details of the method have not be found as of yet.

1. The addition of benzyl chloride to Sodium Metal to obtain benzyl sodium.

C6H5.CH2Cl + 2Na = C6H5.CH2Na + NaCl

This raises the question, is this a straight addition if so wouldn't this happen.

C6H5.CH2Cl + Na = C6H5.CH2 (hypotheticaly) + NaCl

The hypothetical C6H5.CH2 would rearrange itself into other compound(s) ?

Or maybe the benzyl chloride would not react with the sodium until excess sodium was available to fill the space where the Chlorine was.

2. The Reaction of benzyl Sodium with ethyl acetate.

C6H5.CH2Na + CH3.COOC2H5 = C6H5CH2COCH3 + C2H5ONa ?

Sodium Ethoxide ?? makes me wonder if that is going to just sit there and not reduce anything, but if there is not a hydrogen doner then maybe it will sit there.

So lets look at this another way, sodium and ethyl acetate.

Bouveault-Blanc method of reduction of esters, consists in refluxing the ester with metallic sodium and an alcohol.....without the alcohol, there is no hydrogen doner so we would we be looking at sodium acetate and C2H5 radical ?

So we have this C2H5 radical that is going to want to join to something ! Umm the C6H5.CH2 ? don't think so !

So maybe there is another reagent involved in the reaction to send things in the phenylacetone direction that isn't a hydrogen doner ?

My thinking continues.......................................

And my thinking also continues with using lithium instead of sodium.......................................

One day I'll understand everything !
(Hive Prodigy)
01-19-02 05:30
No 258203
      Re: P2P via Benzyl Sodium  Bookmark   

Free Radicals are unstable and highly reactive. More often than not, they are responsible for our beloved black crap tar when a reaction goes wrong.

Also I don't know if this reaction is minimized with sodium and lithium, but with potassium it is very common for PhCH2K + PhCH2Cl --> KCl + PhC2H4Ph a.k.a. (PhCH2)2 a.k.a. absolutely worthless compound.


Vivent Longtemps la Ruche!
(Hive Bee)
01-21-02 08:41
No 258899
      Re: P2P via Benzyl Sodium  Bookmark   

Organic alkali-metal compounds of mixed aromatic-aliphatic hydrocarbons are also known. Sodium benzyl, C6H5CH2Na, and sodium triphenylmethyl, (C6H5)3CNa, are specially interesting on account of their redcolour, and the fact that the sodium is linked ionically with the hydrocarbon radical.
(Organic Chemisty - Paul Karrer 1947)

See Post 258901 (Elementary: "Re: Benzyl Sodium ?", Chemistry Discourse)

One day I'll understand everything !
(Ubiquitous Precursor Medal Winner)
01-21-02 09:38
No 258918
      Re: P2P via Benzyl Sodium  Bookmark   

Another specially interesting thing about benzyl sodium besides its redness, is the fact it's spontaneously flammable in air. Same with the lithium compound, I expect.

turning science fact into <<science fiction>>
(Hive Bee)
01-23-02 02:21
No 259630
      Re: P2P via Benzyl Sodium  Bookmark   

I have found references of lithum alkyls being used in the synthesis of ketones.

Post 258901 (Elementary: "Re: Benzyl Sodium ?", Chemistry Discourse)

Another reference discribes the synthesis of ketones from esters of carboxylic acids. The condensation reaction takes place under the influence of sodium ethylate:


The keto-carboxylic acids formed decompose on hydrolysis with dilute alkalis into carbon dioxide and ketone


So if this happens with sodium ethylate could simular be happening with the benzyl sodium with ethyl acetate to give us the phenylacetone ?

One day I'll understand everything !
(Hive Bee)
01-24-02 16:54
No 260342
      Re: P2P via Benzyl Sodium  Bookmark   

Post 260327 (halfapint: "Re: Benzyl Sodium ?", Chemistry Discourse)

One day I'll understand everything !