METHOD OF 1-ALKYL-3-CYAN-4-METHYL-6-HYDROXY-2-PYRIDONE-TYPE MIXED AZO-COUPLING COMPONENTS PREPARATION

Method of preparation of homological mixtures of pyridone azo-coupling components with defined composition of general formula (l), whereas individual components of the mixture are differentiated by substituent R, which is a hydrogen atom, or various low linear or branched alkyls with 1 to 8 carbon atoms, based on a singular synthetic operation of the reaction of acetoacetic acid ester with the defined homological mixtures of N-R-substituted amides of cyanoacetic acid from alkaline catalysis by an aqueous solution of ammoniac, and/or primary aliphatic amines, and/or monoethanolamine at 80 to 115 degrees C, whereas the composition of the mixture in the reaction of the acquired compounds of general formula (l) is stoichiometrically specified by the molar ratio of amides of cyanoacetic acid used in the reaction. In the reaction the required mixture of N-R-substituted amides of cyanoacetic acid is preferably prepared concurrently in the same reactor of the reactions of esters of cyanoacetic acid with the defined mixture of the aqueous solutions of the corresponding amines of R-NH2 added to the reaction in the given stoichiometric ratio.