Year: 1897

page_text: A communication from abroad by WILLIAM J. MATHESON AND COMPANY,
LIMITED, a corporation organised under the laws of the State of New York,
having its place of business at 178 Front Street, New York City, New York,
United States of America.
I, JOHN CORRY FELL, of the Firm of Fell and James, of 1 Queen Victoria
Street, in the City of London, Chartered Patent Agent, 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.
Heretofore acetanilid and the acetoluids have been made by the action of glacial
(anhydrous) acetic acid, acetic anhydrid, or acetyl chlorid on the respective amins.
The practice has been to use the acid in the most concentrated and anhydrous form
because the reaction depends upon the elimination of water as shown by the
equation:
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It has, therefore, been supposed that the presence of water should be avoided,
and all experience up to the present has supported this view. Even after boiling
anilin with glacial acetic acid for ten hours in a flask connected with a reflux
condenser, a certain amount of the anilin is found to be still unconverted into
acetanilid.
The cost of glacial acetic acid as compared with the weaker grades, such as
50%, 33%, and of the crude acetic acid known as pyroligneous acid, which are
the ones usually met with in commerce, is high, and hence the cost of acetanilid is
correspondingly great.
I have found that on heating anilin, or the toluidins under pressure with acetic
acid, weaker than anhydrous acetic acid, for instance with acid of 50%, or of 33%
or even with the crude pyroligneous acid, acetanilid or the acetoluids is formed.
This discovery allows of the use of the cheaper grades of acetic acid in making
acetanilid and the acetoluids, and renders it possible to produce them at a lower
cost than heretofore.
As an example of the process of making acetanilid by my method, I will explain
the production of acetanilid with acetic acid of 50% strength. Anilin oil and 50%
acetic acid are well mixed, whereby a clear solution results. A proportion which
has given me good results, is one part by weight of anilin and one and one half to
one and three quarters parts by weight of acetic acid of 50% This quantity of
acetic acid is about 30% more than the calculated amount for the acetylization of
the anilin. The solution is then heated in an autoclave or suitable pressure
apparatus, at a temperature of 150° to 160° C., at a pressure of about 50 lbs. for
about thirty hours, or until the anilia is satisfactorily converted into acetanilid.
The resulting liquid is then run out into suitable receptacles, when on cooling it
solidifies to a mass of acetanilid mixed with dilute acetic acid. The mixture may
be distilled, the acetic acid and water going over first and then the acetanilid, or the
free acetic acid may be neutralized by the addition of a solution of caustic soda,
and the liquid allowed to drain away from the acetanilid. The acetanilid is then
11

page_text: purified by crystalization. The solution of sodium acetate, obtained as just described,
is concentrated and allowed to crystalize. A small amount of acetanilid is
separated from the concentrated solution before the crystalization of sodium acetate
takes place. If acetic acid of other than 50% strength is used, a proportionate
amount should be employed.
To make the acetoluids the corresponding proportions of the raw materials
should be used as in the production of acetanilid.
My process works more satisfactorily when the quantity of acetic acid, as
compared with the quantity of anilin or the toluidins employed, is in excess of
.theoretical requirements. Therefore, the quantity of acetic acid employed may be
varied as the manufacturer may deem best to his advantage.
The preceding method is the best to me at present known. But as temperature
and time and pressure are frequently convertible conditions in chemical reactions,
I do not limit myself to the exact time or temperature, nor the exact pressure, nor
to the exact proportions, nor to the acetic acid of the exact strength above set
forth, the essence of my invention being that when acetic acid, so dilute that it
cannot be used for the commercial manufacture of acetanilid or the acetoluids, by
boiling with the amin under a reflux condenser in the usual manner, is heated with
anilin or the toluidins under pressure, the amin is converted into acetanilid or the
acetoluids.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
.
The within described process of producing acetanilid or the acetoluids, which
consists in mixing dilute acetic acid as herein before described with the amin, and
subjecting the mixture to heat and pressure, above or in excess of that of the
atmosphere, until the conversion is satisfactorily completed, substantially as and for
the purpose described.
Dnd this ash dow of Mouch 1807