Improvements in the Method of Preparing Aldehydes from Alcohols.
Year: 1897

page_text: Date of Application, 28th May, 1897
Complete Specification Left, 23rd Feb., 1898-Accepted, 30th Apr., 1898
PROVISIONAL SPECIFICATION.
Improvements in the Method of Preparing Aldehydes from Alcohols.
JULIUS BEREND COHEN, of 15, Regent Park Avenue, in the City of Leeds, Doctor
of Philosophy, Lecturer on Chemistry, do hereby declare the nature of this inven-
tion to be as follows:-
My improved method of preparing aldehydes & ketones consists in submitting
the corresponding alcohols to the action of nitrogen trioxide or nitrogen tetroxide
either in the gaseous or liquid state or in solution in chloroform or other suitable
solvent. The invention offers a new method for the manufacture of benzaldehyde
and its homologues and the numerous derivatives of these products such as chloro-
benzaldehydes, nitrobenzaldehydes, amidobenzaldehydes, oxybenzaldehydes, all of
which can be employed for the manufacture of colouring matters and for other
purposes.
The alcohol is treated with a solution containing from 10 to 20 per cent. of
either nitrogen trioxide or nitrogen tetroxide dissolved in a suitable solvent such
as chloroform. For example I prepare orthonitrobenzaldehyde as follows: I add
one molecular equivalent of orthonitrobenzyl alcohol in powder to a cooled solution
containing one molecular equivalent of nitrogen trioxide or nitrogen tetroxide in
chloroform or other suitable solvent. I allow the mixture to stand for several
days and I then remove the oxides of nitrogen from the chloroform, which con-
tains the aldehyde. This may be done by pouring the mixture into an excess of
dilute caustic soda solution with stirring. I then separate, dry and distil the
chloroform solution. The residue which remains after the chloroform is distilled
contains the orthonitrobenzaldehyde.
D: oth
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1007
COMPLETE SPECIFICATION.
Improvements in the Method of Preparing Aldehydes from Alcohols.
I, JULIUS BEREND COHEN, of 15, Regent Park Avenue, in the City of Leeds,
Doctor of Philosophy, Lecturer on Chemistry, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:―
My invention consists in preparing aromatic aldehydes from the corresponding
alcohols by the action of nitrogen tetroxide either in the form of gas or liquid, or in
solution in chloroform or other suitable solvent such as ether or liquid paraffins
in which this substance is not decomposed.

page_text: The invention can be employed in the manufacture of benzaldehyde, its
homologues, and the numerous derivatives of these substances such as chloro-
benzaldehydes, nitrobenzaldehydes, oxybenzaldehydes; many of which
employed in the manufacture of colouring matters and for other purposes.
are
As an example of how the process may be carried out, assume that I wish with
a 10 to 20 per cent. solution of nitrogen tetroxide in chloroform to prepare ortho-
nitrobenzaldehyde, then I would proceed as follows:
For each molecular equivalent of nitrogen tetroxide in solution I would add
one molecular equivalent of orthonitrobenzyl alcohol, the mixture being kept cool
and then allowed to stand at the ordinary temperature until the reaction was
completed, after which the oxides of nitrogen and the chloroform would be
removed. This may be done by distillation or by pouring the chloroform solution
which now contains the aldehyde into dilute caustic soda solution and then.
separating the chloroform solution and distilling off the chloroform. The residue
in either case would contain the orthonitrobenzaldehyde. In lieu of using the
tetroxide in the forni of a liquid solution good results may be attained by placing
the orthonitrobenzyl alcohol in a suitable closed vessel and there submitting it to
the action of nitrogen tetroxide in a gaseous form. Other aldehydes may be pro-
duced in like manner.
Although in the Provisional Specification it is stated that the invention is
applicable to the manufacture of ketones, and that nitrogen trioxide may be
employed, my later experiments tend to show that the process cannot be satis-
factorily carried out for preparing ketones, and that the reaction when using
nitrogen trioxide is not satisfactory.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
-
The manufacture of aromatic aldehydes from the corresponding alcohols by
causing said alcohols to be acted upon by nitrogen tetroxide in the form of gas
or liquid, or in solution in chloroform or other solvent of nitrogen tetroxide in
which this substance is not decomposed.
EVRO
Daten the way
חזז on tha
PHILIP M. JUSTICE,
55 and 56, Chancery Lane, London,
Chartered Patent Agent, for the Applicant.