Patent GB-628837-A (GB)
Title: Improvements in and relating to the preparation of dyestuff intermediates and of dyestuffs therefrom
IPC: C09B23/01
Filed: 1946-12-13
Abstract: Dye intermediates are prepared by reacting together a pyridinium salt having a labile nitrogen atom and a compound of the formula <FORM:0628837/IV (b)/1> wherein Z represents the non-metallic atoms to complete a heterocyclic nucleus, in the presence of a strong basic condensing agent, e.g. triethylamine, or by reacting together pyridine, a compound QX (where Q is 2 : 4-dinitrophenyl, cyano, pyridyl, benzoxazolyl, pyridyl alkyl halide, or quinolyl alkyl halide, and X is an acid residue), and the reactive methylene compound. Intermediates are prepared by refluxing together (a) 1-phenyl-3-methyl-5-pyrazolone, 2 : 4-dinitrophenylpyridinium chloride, ethyl alcohol, and triethylamine; (b) 1-p-sulphophenyl-3-methyl - 5 - pyrazolone, 2 : 4 - dinitrophenyl-pyridinium chloride, methyl alcohol, and triethylamine; and (c) thiobarbituric acid, 2 : 4-dinitrophenylpyridinium chloride, ethyl alcohol, and triethylamine.ALSO:Dyes and dye intermediates are prepared by reacting together a pyridinium salt having a labile nitrogen atom and a compound of the formula <FORM:0628837/IV (c)/1> wherein Z represents the non-metallic atoms to complete a heterocyclic nucleus, in the presence of a strong basic condensing agent, e.g. triethylamine.  Alternatively, the dyes and dye intermediates may be prepared by reacting together pyridine, a compound QX (wherein Q is 2:4-dinitrophenyl, cyano, pyridyl, benzoxazolyl, pyridyl alkyl halide, or quinolyl alkyl halide, and X is an acid residue) and the reactive methylene compound.  Dyes may also be prepared by reacting the intermediates produced as above with a reactive cyclomethylene compound or a cyclammonium salt having a reactive methyl group or the corresponding methylene base.  The pyridinium salt may be 2:4-dinitrophenylpyridinium chloride, cyanopyridinium bromide, 4 - pyridylpyridinium chloride, (2-pyridyl alkyl halide)-pyridium halide, (2-quinolyl alkyl halide)-pyridinium halide, of 1-benzoxazolylpyridinium chloride.  Intermediates are prepared by refluxing together (a) 1-phenyl-3-methyl-5-pyrazolone, 2:4-dinitrophenylpyridinium chloride, ethyl alcohol, and triethylamine; (b) 1-(p-sulphophenyl)-3-methyl - 5 - pyrazolone, 2:4 - dinitrophenylpyridinium chloride, methyl alcohol, and triethylamine; and (c) thiobarbituric acid, 2:4-dinitrophenylpyridinium chloride, ethyl alcohol, and triethylamine.  Dyes are prepared by refluxing together (d) intermediate (a), N-methylrhodanine, alcohol, and triethylamine; (e) intermediate (b), N-phenylrhodanine, ethyl alcohol, and triethylamine; (f) intermediate (c), 1-(p-sulphophenyl)-3-methyl-5-pyrazolone, ethyl alcohol, and triethylamine; (g) intermediate (a), 2-methylbenzthiazole methiodide, pyridine, and triethylamine; (h) 1-phenyl-3-methyl-5-pyrazolone, (2-quinolyl-ethiodide)-pyridinium iodide, ethyl alcohol, and triethylamine; (i) 1-(p-sulphophenyl)-3-methyl-5-pyrazolone, 2 : 4 - dinitrophenylpyridinium chloride, methyl alcohol, and triethylamine; and (j) 1-phenyl-3-methyl-5-pyrazolone, 2:4-dinitrochlorbenzene, pyridine, ethyl alcohol, and triethylamine.