Re: ORGLIST: Reduction with Sodium

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From: srinivas reddy (gounisrinivas$##$yahoo.com)
Date: Sun Dec 18 2005 - 02:05:11 EST


hi,

its advised to add sodium at short intervals.

here is some procedure and referenceabout n-Butanol/Na
from the web:

Reduction of Nitriles and Oximes with Na/n-Butanol

The usefulness of n-butyl alcohol in the sodium
reduction of a number of aliphatic cyanides and oximes
has been investigated. In a considerable number of
preliminary experiments upon the reduction of n-butyl
cyanide it was found that: (1) better results were
obtained by adding the sodium to the boiling solution
of the cyanide than by adding the cyanide solution to
the sodium; (2) if the temperature of the reaction
mixture were kept below the boiling point mechanical
stirring increased the yield of amine, but it was of
no advantage to stir the refluxing solution; (3)the
use of more than 7 atoms of sodium per mole of cyanide
did not appreciably increase the yield of amine; and
(4) all of the sodium dissolves within a convenient
time if slightly more than 3 moles of n-butyl alcohol
is used per atom of sodium. It is probable that would
not be true for all reductions of this type. The
yields of amines from a series of methyl alkyl
ketoximes varied from 69 to 86% of the theoretical
amounts. Heptaldoxime gave 69% of the amine. n-Butyl
and n-amyl cyanide gave 86 and 78%, respectively, of
the corresponding amines.

Procedure

A solution of 1 mole of cyanide or oxime in 2300 cc.
of n-butyl alcohol in a 5-liter two-necked flask
fitted with a reflux condenser was heated to boiling
and 161 g. (7 moles) of sodium added in 10-20 g.
pieces at short intervals through the large neck of
the flask. This required from ten to fifteen minutes.
After the reaction had moderated the mixture was
refluxed until practically all of the sodium had
dissolved. The reaction mixture was allowed to cool,
1.5 liters of water added and the mixture distilled to
remove the amine and alcohol. More water was added as
necessary. The distillate was made slightly acid with
hydrochloric acid and distilled to a volume of 300 ml,
500 ml of water added and distillation continued until
no more alcohol came over. The water solution of amine
hydrochloride was saturated with sodium hydroxide, the
upper oily layer of amine separated and further dried
over sodium hydroxide and then over sodium. The amine
was now distilled from sodium in a 250ml special
Claisen flask. If the amine is properly dried there is
very little forerun and no high boiling residue.

reference: J. Am. Chem. Soc. 56, 487 (1934) (old
though).

hope this is helpful.

regards

Srinivas





--- Nalini Patel <nalini.patel$##$rediffmail.com> wrote:

> Hello Friends !
>
> I'm doing one reduction reaction of Oxime to Amine
> ON PLANT LEVEL in n-Butanol with sodium. Here I'm
> not aware of properly performing this sodium
> handling reaction & wish to get some advices from
> you friends :
>
> a) Is it necessary to stirr the reaction (slowly or
> fast ?) or not, while adding sodium pieces at reflux
> temp. of solvent to get better yield of Amine ?
>
> b) Proper method of addition of sodium, i.e. adding
> big pieces at long intervals or small pieces at
> short intervals.
>
> c) Any more advices from you & suggesting references
> for such reduction reaction.
>
>
>
> Awaiting comments from all of you !
>
>
>
>
> Regards,
> NALINI
>
>
>
>
> > _______________________________________________
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