Improvements in the Manufacture of an Aromatic Ether.
Year: 1899

page_text: Date of Application, 2nd Jan., 1899
Complete Specification Left, 1st Sept., 1899-Accepted, 7th Oct.,
1899
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of an Aromatic Ether.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Build-
ings, Chancery Lane, in the County of London, do hereby declare the nature of.
this invention (as communicated to me from abroad by The Actien Gesellschaft
für Anilin Fabrikation, of Berlin, in the Empire of Germany, Chemical Manu-
facturers), to be as follows:-
-
By treating the solution of anthranilic acid in methyl alcohol with acids my
foreign correspondents succeeded in obtaining the methyl ether of anthranilic
acid. They have now found that the same ether can be prepared by using as
starting products instead of anthranilic acid either suitable metallic salts of that
acid, or acetyl-anthranilic acid or finally orthonitrobenzoic acid. The preparation
of the methyl ether of anthranilic acid from these starting products may be
effected in the following way:
1). A suitable metallic salt of anthranilic acid, for instance the silver or lead
compound is treated with methyl iodide preferably diluted with methyl alcohol
and the ether thus formed is isolated in the known manner.
2). A suitable metallic salt of acetyl-anthranilic acid, for instance the silver
or lead compound is treated with methyl iodide preferably diluted with methyl
alcohol.
The methyl ether of acetyl-anthranilic acid thus formed is then converted
into a salt of the ether of anthranilic acid by heating it with mineral acids and
the free ether is precipitated from the solution of the salt thus obtained by
addition of an alkali.
3). Acetyl-anthranilic acid is heated with methyl alcohol and mineral acids. By
proceeding in this way the saponification of the acetyl-derivative and the forma-
tion of the methyl ether are effected in a single operation. A salt of the methyl
ether of anthranilic acid is produced, from the solution of this the free ether
is precipitated by addition of an alkali.
4). Orthonitrobenzoic acid is treated with reducing agents, for instance with
stannous chloride and hydrochloric acid with addition of alcohol, and the ether
thus formed is isolated in the known manner.
Dated this 2nd day of January 1899.

page_text: hydrochloride of the methyl ether of anthranilic acid separates in crystalline
form. From this salt the free ether is obtained in the manner described in
Specification No. 19868 of 1898.
EXAMPLE 4.
I kilo of the methyl ether of orthonitrobenzoic acid (obtained in the known
manner by treating orthonitrobenzoic acid dissolved in methyl alcohol with
mineral acids) is added to the warm solution of 4 kilos. of stannous chloride in
a mixture of 12 litres of concentrated hydrochloric acid and 6 litres of alcohol.
A clear solution is produced from which, after cooling, the tin double salt of
the amido-product separates. The methyl ether of anthranilic acid is obtained
from this double salt by neutralizing with sodium carbonate and distilling with
steam. The reduction can be as well effected by means of other reducing agents,
such as zinc-dust and hydrochloric acid, tin and hydrochloric acid and the like.
Having thus particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim
is:-
:
1. The herein described manufacture of the methyl ether of anthranilic acid
by treating suitable metallic salts of anthranilic acid with methyl iodide.
2. The herein described manufacture of the methyl ether of anthranilic acid
by treating suitable metallic salts of acetyl-anthranilic acid with methyl iodide,
eliminating the acetyl-group from the methyl ether of acetyl-anthranilic acid
thus produced, and decomposing the salt of the other thus formed by an alkali.
3. The herein described manufacture of the methyl ether of anthranilic acid
by heating acetyl-anthranilic acid with methyl alcohol and a mineral acid and
decomposing the salt of the ether thus formed by an alkali.
4. The herein described manufacture of the methyl ether of anthranilic acid by
treating the methyl ether of orthonitrobenzoic acid with suitable reducing agents.
Dated this 1st day of September 1899.
ABEL & IMRAY,
Agents for the Applicant.