Year: 1898

page_text: I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
Chancery Lane, in the County of London, Consulting Engineer and Chartered Patent
Agent, 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 Manufacturers) to be as follows:-
By the action of methyl alcohol on isatoic acid, G. Schmidt, (Journal für praktische
Chemie/2/36,374) obtained as an accessory product a yellow coloured liquid, which he
found to possess the composition of a methyl ether of anthranilic (orthamidobenzoic)
acid.
It appears, however, that this product cannot have been pure anthranilic methyl
ether. This follows from the observation of my correspondents, who have succeeded
in obtaining the said ether in a chemically pure formn by a new process and have found
its properties to differ essentially from those of Schmidt's product. While Schmidt's
product is described as a yellow oil, the compound obtained by my
spondents is at ordinary temperature a solid substance forming nearly colourless
crystals. The new product is moreover characterized by its sweet and intense smell,
which resembles that of orange blossoms and could not have escaped the attention of
any chemist who got the product into his hands.
corre-
It is therefore probable that Schmidt's product did either not contain the methyl
ether of anthranilic acid at all or only in a state of great impurity.
The new process for the manufacture of pure methyl ether of anthranilic acid con-
sists in treating the solution of anthranilic acid in methyl alcohol with acids, such as
hydrochloric, sulphuric, phosphoric acid or of strong organic sulphonic acids.
The following example may serve to illustrate the new process.
In a suitable vessel provided with an inverted condenser a solution of 1 kilo.
anthranilic acid in 5 litres of methyl alcohol is saturated with gaseous hydrochloric
acid. The formation of the methyl ether is accompanied by a considerable rise of
temperature of the mixture which at last begins to boil. It is allowed to stand for
several hours, then the larger part of the alcohol is distilled off on the water
bath.
By addition of a solution of sodium carborate to the residue the new ether is
separated in the form of an oily liquid which is washed with water and thereupon
distilled in vacuo.
The methyl ether of anthranilic acid obtained in the manner described is represented
by the following formula:-

page_text: easily in mineral acid, in alcohol, ether and other organic solvents, but only sparingly
in water. All its solutions show a beautiful blue fluorescence.
On treating the solution of the new compound in ether or benzene with gaseous
hydrochloric acid, the hydrochloride of the methyl ether of anthranilic acid separates
in the form of colourless needles melting at 178 C.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
The Manufacture of an Aromatic Ether.
· I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Build-
ings, Chancery Lane, in the County of London, Consulting Engineer and Chartered
Patent Agent, 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 Manufacturers) and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
By the action of methyl alcohol on isatoic acid, G. Schmidt (Journal für praktische
Chemie [2]36, 374) obtained as an accessory product a yellow coloured liquid, which
he found to possess the composition of a methyl ether of anthranilic (orthamido-
benzoic) acid.
It appears, however, that this product cannot have been pure anthranilic methyl
ether. This follows from the observation of my correspondents, who have succeeded
in obtaining the said ether in a chemically pure form by a new process and have
found its properties to differ essentially from those of Schmidt's product. While
Schmidt's product is described as a yellow oil, the compound obtained by my corre-
spondents is at ordinary temperature a solid substance forming nearly colourless
crystals. The new product is moreover characterized by its sweet and intense
smell, which resembles that of orange blossoms and could not have escaped the
attention of any chemist who got the product into his hands.
It is therefore probable that Schmidt's product either did not contain the methyl
ether of anthranilic acid at all or only in a state of great impurity.
The new process for the manufacture of pure methyl ether of anthranilic acid
consists in treating the solution of anthranilic acid in methyl alcohol with an acid,
such as hydrochloric, sulphuric, phosphoric acid or a strong organic sulphonic
acid.
The following example may serve to illustrate the new process.
In a suitable vessel provided with an inverted condenser a solution of 1 kilo.
anthranilic acid in 5 litres of methyl alcohol is saturated with gaseous hydrochloric
acid. The formation of the methyl ether is accompanied by a considerable rise of
temperature of the mixture which at last begins to boil. It is allowed to stand for
several hours, then the larger part of the alcohol is distilled off on the water bath.
By addition of a solution of sodium carbonate to the residue the new ether is
separated in the form of an oily liquid which is washed with water and thereupon
distilled in vacuo.

page_text: It forms colourless crystals of blue fluorescence, which melt at 25° C. and which,
distilled in vacuo at a pressure of 11mm. boil at 127° C. The new ether dissolves
easily in mineral acid, in alcohol, ether and other organic solvents, but only sparingly
in water.
All its solutions show a beautiful blue fluorescence.
On treating the solution of the new compound in ether or benzene with gaseous
hydrochloric acid, the hydrochloride of the methyl ether of anthranilic acid separates
in the form of colourless needles melting at 178° C.
Having now particularly described and ascertained the nature of this inven-
tion 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 anthranilic acid with methyl alcohol and an acid and decomposing the salt
of the ether thus formed by means of an alkali.
2. The methyl ether of anthranilic acid manufactured as above set forth.
1000
Dated this 5th day
June 1893.
ABEL & IMRAY,
Agents for the Applicant.