Year: 1899

page_text: Date of Application, 16th Jan., 1899
Complete Specification Left, 29th Sept., 1899-Accepted, 4th Nov., 1899
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals: Meister
Lucius and Brüning, of Hoechst a/Main, in the Empire of Germany, Chemical
Manufacturers) to be as follows:-
In the Specification No. 9690 of 1898 is described a method of transforming neutral
esters of phenylglycine-ortho-carboxylic acid into indoxyl-carboxylic acid esters by
means of sodium alcoholate or metallic sodium.
My foreign correspondents have further found, that formation of indoxyl-derivatives
always takes place, if esters of aromatic ortho-amidocarboxylic acids, which contain at
the nitrogen atom the group
CH,−CO<
he subjected to the action of sodium or sodium alcoholate. Such compounds may be
obtained, if ortho-amido-carboxylic acid esters be combined with halogenacetone,
halogenacetaldehyde, w-halogenacetophenone and the like.
The only important are the acetonylanthranilic acid esters which can be obtained
easily by heating 1 molecular proportion of halogenacetone with 2 molecular propor-
tions of anthranilic acid ester. If both substances be allowed to act upon each other
in the presence of agents capable of combining with hydrochloric acid, such as alkalies,
carbonates or acetates, then, of course, the second molecule of anthranilic acid ester
is superfluous.
The process is illustrated by the following example :-
330 parts by weight of anthranilic acid ethyl ester and 92.5 parts by weight of
chloracetone are heated on the water bath until the chloracetone has disappeared.
On completion of the reaction, a solution of 55 parts by weight of soda is added and
the mixture obtained of acetonylanthranilic acid ester and anthranilic acid ester is
dissolved in 1000 parts of benzene. Then 23 parts by weight of finely divided
metallic sodium is added to the well dried solution.
The reaction may be accelerated by the addition of a few drops of alcohol, while
gently heating.
The reaction is illustrated by the following formula:

page_text: When the sodium has disappeared, the mass is allowed to cool down and is then
shaken with dilute acid to decompose the sodium compound. From the layer of
benzene which, besides indoxylmethylketone still contains anthranilic acid ester, the
former may be removed by means of dilute soda-lye. The ketone is only partially
removed from the alkaline solution by carbonic acid and completely only by acetic acid or
dilute mineral acids. It is a pale yellow substance having the melting point 153° C.
It is easily soluble in ether, alcohol or benzene, soluble with difficulty in chloroform.
On heating with caustic alkali a yellow mass is obtained from the aqueous solution of
which when exposed to air indigo separates. The indoxylmethylketone is soluble in
concentrated sulphuric acid with a yellow colour, becoming blue when heated with
formation of indigo. The substance is characterized as a ketone by forming a
hydrazone with phenylhydrazine and by eliminating chloroform when heated with
alkaline hypochlorite solution.
In this example for the anthranilic acid ethyl ester may be substituted any other
anthranilic acid ester, and for the metallic solium may be substituted sodium
alcoholate without change in the result.
Dated this 10th day & Lunuance 1800
ABEL & IMRAY,
Agents for the Applicant.
be subjected to the action of sodium or sodium alcoholate.
Such compounds may be obtained if ortho-amido-carboxylic acid esters be combined
with halogenacetone, halogenacetaldehyde, w-halogenacetophenone and the like.
The only important are the acetonylanthranilic acid esters which can be obtained
easily by heating 1 molecular proportion of halogenacetone with 2 molecular
proportions of anthranilic acid ester. If these substances be allowed to re-act with
each other in the presence of agents capable of reacting with hydrochloric acid to
form a chloride, such as alkalies, carbonates or acetates, then, of course, the second
molecular proportion of anthranilic acid ester is superfluous.
The process is illustrated by the following example :-
330 parts by weight of ethylant hranilate and 925 parts by weight of chloracetone
are heated on the water bath until the chloracetone has disappeared. On completion
of the reaction, a solution of 55 parts by weight of sodium carbonate is added and
the mixture of ethylacetonyl-anthranilate and ethylanthranilate thus obtained is

page_text: dissolved in 1000 parts of benzene. Then 23 parts by weight of finely divided
metallic sodium are added to the well dried solution.
The reaction may be accelerated by an addition of a few drops of alcohol, gentle
heat being applied. The reaction is illustrated by the following formula:
ketone (Na-compound)
When the sodium has disappeared the mass is allowed to cool down and is then
shaken with dilute acid to decompose the sodium compound. From the layer of
benzene which, besides indexylmethylketone still contains ethyl anthranilate, the
former may be removed by means of dilute soda-lye. The ketone is only partially
removed from the alkaline solution by carbonic acid and completely only by acetic
acid or dilute mineral acids. It is a pale yellow substance having the melting
point 153° C. It is easily soluble in ether, alcohol or benzene, soluble with difficulty
in chloroform.
On heating with caustic alkali a yellow mass is obtained from the aqueous
solution of which when exposed to air, indigo separates.
The indoxylmethylketone is soluble in concentrated sulphuric acid forming
a yellow coloured solution becoming blue when heated owing to production of indigo.
The substance is characterized as a ketone by forming a hydrazone with phenyl-
hydrazine and by yielding chloroform when heated with alkali hypochlorite solution.
In this example for the ethyl anthranilate may be substituted any other
anthranilic acid ester, and for the metallic sodium may be substituted sodium
alcholate without change in the result.
Having now 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 indoxylmethylketone by subjecting an
ester of acetonylanthranilic acid to the action of sodium or sodium alcoholate.
2. The indoxylmethylketone manufactured as above set forth.
Dated this 29th day of September 1899