Patent GB-377419-A (GB)
Title: Process for the preparation of new condensation products of the anthraquinone series
Filed: 1931-07-17
Abstract: Anthrapyridones are prepared by condensing anthraquinone derivatives of the general formula:  <FORM:0377419/IV/1> wherein R represents hydrogen or an alkyl group, X represents hydrogen, a halogen, or an alkyl or alkoxy group, Y represents hydrogena halogen, or a hydroxy, alkoxy, amino, alkylamino or arylamino group, Z represents hydro, gen, a halogen, or a hydroxy, alkoxy, amino, alkylamino or arylamino group, with esters of the formula: RCOCH2COO alkyl, wherein R represents an alkyl, alkoxy, or phenyl group, in the presence of condensing agents of a weak basic character and in the presence or absence of organic solvents.  The products are C-carbalkoxy-or-C-acetylanthrapyridones according to the ester employed in the condensation.  The presence of a condensing agent is essential if the starting materials are pure, but with commercial initial materials they may be dispensed with.  Suitable weakly basic condensing agents are formates, acetates, nitrites, carbonates, borates, sulphites of alkali metals, calcium oxide, magnesium oxide. In examples a -aminoanthraquinone is condensed with diethylmalonate in presence of sodium acetate to give C-carbethoxyanthrapyridone; 1 : 5-diaminoanthraquinone is condensed with acetoacetic ester in presence of sodium acetate to give a C : C<1>-diacetylanthrapyridone; 1-methyl-amino-4-bromanthraquinone is condensed with ethyl malonate in presence of sodium acetate and with acetoacetic ester to C-carbethoxy- and C-acetyl-N-methyl-4-bromanthrapyridone; 1-methylamino-5-chloranthraquinone is condensed with acetoacetic ester in presence of sodium carbonate or sodium or potassium acetate to give 5-chlor-C-acetyl-N-methylanthrapyridone; 1-amino-2-methyl-4-bromanthraquinone is condensed with malonic ester or acetoacetic ester in presence of sodium carbonate (or calcium oxide), magnesium oxide, sodium phosphate or sodium sulphite to give 2-methyl-4-bromo-C-carbethoxy- and C-acetylanthrapyridone; 1-amino-2 : 4-dibromanthraquinone is condensed with malonic ester or acetoacetic ester to give C-carbethoxy or C-acetyl-2 : 4-dibromanthrapyridone; 1-amino-4-methoxyanthraquinone is condensed with acetoacetic ester in presence of sodium acetate or with malonic ester to give C-acetyl- or C-carbethoxy-4-methoxyanthrapyridone, 1-amino-5-oxyanthraquinone is condensed with malonic ester or acetoacetic ester to give C-carbethoxy-or-C-acetyl-5-oxyanthrapyridone; 1-amino-2-bromo-4-p-toluidoanthraquinone is condensed with malonic ester or acetoacetic ester to give 4-p-toluido-2-bromo-C-carbethoxy-pyridone or 4-p-toluido-2-bromo-C-acetylanthra-pyridone; instead of 1-amino-2-brom-4-p-toluidoanthraquinone other arylaminoanthraquinones may be used such as the anilido-, xylidino, chloranilido, amidophenolethers-, amidocresolethers, phenylenediamido derivatives, or 1-amino-2-methyl-4-arylaminoanthraquinones, 1-amino-4-arylaminoanthraquinones-1-amino-5-arylaminoanthraquinone may be, employed: 1-amino-2-methyl-4-bromanthraquinone is condensed with benzoylacetic ester in presence of sodium acetate to give C-benzoyl-2-methyl-4-bromanthrapyridone.  It is also stated that 1-aminoanthraquinone may be condensed with malonic ester to give o -carbethoxyacetylaminoanthraquinone which is converted on boiling with an aqueous caustic soda solution into a C-carboxyanthrapyridone. Specifications 28765/06, [Class 2, Acids and salts, Organic &c.], and 299,349, [Class 2 (iii), Dyes &c.], are referred to.