DE280190C - - Google Patents

Description

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■ - JVr 280190 CLASS 226th GROUP

the anthraquinone series.

Addendum to patent 270789.

Patented in the German Empire on March 19, 1913. Longest duration: December 13, 1927.

Patent 270790 describes new nitrogen-containing condensation products of the anthraquinone series, α-anthraquinonyl-N-arylglycines, which are obtained by condensation of salts of aromatic glycines with α-halogen substitution products of anthraquinone. A process for the preparation of nitrogen-containing condensation products of the anthraquinone series, a-anthra-N-arylpyrroles, is then protected by the main patent 270789, which consists in ^{heating the aforementioned α-anthraquinonyl-1} N-arylglycines with acetic acid hydride. Here, with elimination of water and carbonic acid, a ring closure occurs with formation of the a-anthra-N-arylpyrroles. If one tries to carry out the latter condensation with other agents, such as sulfuric acid, oleum, chlorosulphonic acid or alcoholic caustic alkali, one always obtains aryl-α-aminoanthraquinones or their sulphonic acids; all of the acetic acid residue is split off.

The observation has now been made that a-Anthra-N-arylpyrroles are also obtained but which still contain the carboxyl group if instead of the free glycines their esters in the heat, with or without the application of pressure, the action of alkaline Condensation agents, such as alcoholic caustic alkali, caustic alkali in the presence of indifferent Solvents or alkaline earths.

The esters are surprisingly very stable and the elimination of water is quick and formation of the pyrrole ring precedes saponification. In the a-anthra-N-arylpyrrolecarboxylic acids formed the carboxyl group is firmly bound to acids and alkalis. They are mostly yellow to brown products, which, dissolved in acetate and mixed with acetic acid, dye wool vigorously, with nuances, those from yellow to blue depending on the nature of the substituents still present in the molecule vary.

These a - Anthra - N -arylpyrrolecarboxylic acids are intended to serve as intermediates for the production of dyes.

Example.

36 parts of a-anthraquinonyl-N-phenylglycine, 400 parts of alcohol and 10 parts of concentrated sulfuric acid are refluxed for 5 hours boiled and then most of the alcohol is distilled off. When cooling down the mass solidifies to a dark red crystal cake. It is filtered off with suction, washed with dilute alcohol, pressed and dried. The α-anthraquinonyl-N-phenylglycine ethyl ester thus obtained forms a dark red powder, which dissolves in alcohol with a red color and crystallized from it in little red needles.

60 parts of this ester are mixed with 20 parts of caustic potash and 400 parts of xylene in an autoclave heated with stirring to 150 ° for 2 hours; After cooling, the xylene is driven off with steam, the remaining Lye filtered and the brownish colored fluorescent solution made mineral acid. The a-Anthra-N-phenylpyitolcarboxylic acid

COOH-C-N

precipitates as a yellow colored powder. After vacuuming and drying, it will be removed from minor impurities freed by extraction with benzene. It dissolves in dilute Soda solution with a yellow color and shows a magnificent yellow-green fluorescence. Wool and silk are dyed yellow in an acetic acid bath. It dissolves violet-red in concentrated sulfuric acid, in Oleum and chlorosulfonic acid wine-red with low fluorescence. In organic solvents it is difficult to resolve with green fluorescence. From Pyridiir it crystallizes in small ones yellow colored leaflets.

Claims (1)

Patent claim: Modification of the process for the representation of nitrogen-containing condensation products of the anthraquinone series, consisting of that the α-anthraquinonylarylglycines obtainable by the process of patent 270790 here in the form of their esters with caustic alkalis or alkaline earths in the presence of inert solvents, with or without applying pressure, heated.