Patent GB-560160-A (GB)
Title: New di- and tri-methine dyestuffs
IPC: H04R17/06
Filed: 1942-09-18
Abstract: Di- and tri-methine dyes are obtained by condensing one molecular proportion of a quaternary salt of 3-methylquinoxalone, which may optionally be substituted in the 1-position by an alkyl, aryl, or aralkyl group, with one molecular proportion of a cyclic aldehyde, or, in one or more stages, with one molecular proportion of an arylformamidine or an orthoformic ester, and one molecular proportion of a heterocyclic nitrogen compound containing a reactive methyl or methylene group.  3-methyl-quinoxalone derivatives specified are 2-methyl-3-hydroxyquinoxaline methosulphate, 1 : 3-dimethylquinoxalone methosulphate, 3-methyl-1-phenylquinoxalone methosulphate, and the corresponding quaternary salts from diethylsulphate.  Cyclic aldehydes specified are p-dimethylaminobenzaldehyde, p-(N-methyl: N-o -chloroethylamino)-benzaldehyde, 4-(N-ethyl: N - o  - chloroethylamino) - 2 - methylbenzaldehyde, 1 : 3 : 3-trimethyl-2-aldehydomethylene-indoline, and the aldehydes specified in Specification 438,603.  Heterocyclic nitrogen compounds specified are 2-methylbenzoxazole methiodide, 2-methylbenzthiazole ethiodide, and 2-methyl-3-hydroxyquinoxaline methosulphate.  Compounds capable of forming a methine group are diphenylformamidine, ethyl orthoformate, and N-methyldiphenylformamidine.  Symmetrical and unsymmetrical dyes may be obtained.  In examples, dyes are obtained (1) by boiling 2-methyl-3-hydroxyquinoxaline methosulphate with p-dimethylaminobenzaldehyde and acetic anhydride, and adding aqueous KI; (2) by reacting 2-methyl-3 - hydroxyquinoxaline methosulphate with 1 : 3 : 3-trimethyl-2-aldehydomethyleneindoline, acetic anhydride, and pyridine, and adding aqueous KI; (3) by reacting 2-methyl-3-hydroxyquinoxaline, acetic anhydride, diphenylformamidine, and pyridine; (4) by boiling together 2-methyl-3-hydroxyquinoxaline methosulphate, acetic anhydride, anhydrous sodium acetate, and 2-anilinovinylquinoline methiodide, and adding aqueous KI; (5) by boiling together 2-methylbenzoxazole methiodide, diphenylformamidine, and acetic anhydride, adding anhydrous sodium acetate and 2 - methyl - 3 - hydroxyquinoxaline methosulphate and again boiling, and adding aqueous KI; (6) by boiling together 2-methylbenzthiazole ethiodide, acetic anhydride, and diphenylformamidine, adding 2 - methyl - 3 - hydroxyquinoxaline methosulphate, acetic anhydride, and anhydrous sodium acetate, and again boiling, and adding aqueous KI; (7) by reacting together 1 : 3-dimethylquinoxalone methosulphate, p-dimethylaminobenzaldehyde, acetic anhydride, and pyridine; (8) by boiling together: 3 - dimethylquinoxalone methosulphate, acetic anhydride, 1 : 3 : 3-trimethyl-2-aldehydomethyleneindoline, and pyridine, allowing to cool, adding aqueous NaCl, and heating; (9) by boiling together: 3-dimethylquinoxalone methosulphate, methyl alcohol, ethyl orthoformate, and concentrated sulphuric acid, or by reacting together 1 : 3-dimethylquinoxalone methosulphate, acetic anhydride, diphenylformamidine, and pyridine; (10) by boiling together diphenylformamidine, 2-methylbenzthiazole ethioidide, and acetic anhydride, adding 1 : 3-dimethylquinoxalone ethosulphate, and again boiling, and adding aqueous KI; (11) by heating together 1-phenyl-3-methylquinoxalone methosulphate, acetic anhydride, and p-dimethylaminobenzaldehyde, and adding aqueous NaCl (a similar dye is made from the ethosulphate); and (12) by refluxing together 1 - phenyl - 3 - methylquinoxalone methosulphate, acetic anhydride, 1 : 3 : 3-trimethyl - 2 - aldehydomethyleneindoline, and pyridine, and adding hot aqueous NaCl; (13) by treating 2-methylanilinovinylquinoline methiodide with aqueous Na2CO3 and benzene, separating, drying and evaporating the benzene layer, and adding a pyridine solution of the residue to a mixture of 1-phenyl-3-methylquinoxalone methosulphate and acetic anhydride; (14) by treating 2 - methylanilinovinylbenzthiazole methiodide by the procedure of (13) and adding the pyridine solution of the residue to 1-phenyl-3-methylquinoxalone methosulphate in acetic anhydride and adding aqueous NaCl; (15) by heating together 1 : 3-dimethylquinoxalone methosulphate, acetic anhydride, and p-(N-methyl: N-3-chloroethylamino)-benzaldehyde; and (16) by reacting together 1 : 3-dimethylquinoxalone methosulphate, acetic anhydride, and 4-(N-ethyl : N-o -chloroethylamino)-2-methylbenzaldehyde.  The dyes may be used for cellulose acetate and tannin-mordanted cotton. 2-Methyl-3-hydroxyquinoxaline is obtained by reacting o-phenylenediamine and pyruvic acid.  1 - Phenyl - 3 - methylquinoxalone is similarly obtained from o-aminodiphenylamine.  2 - Methyl - 3 - hydroxyquinoxaline methosulphate is obtained by p heating together 2-methyl-3-hydroxyquinoxaline and dimethyl sulphate. 1 : 3-Dimethylquinoxalone methosulphate, 1 : 3-dimethylquinoxalone ethosulphate, and 1-phenyl-3-methylquinoxalone methosulphate and ethosulphate are similarly prepared.  2 - Methylanilinovinylquinoline methiodide is obtained by reacting 2-methylquinoline methiodide with methyl diphenylformamidine. 2-Methylanilinovinylbenzthiazole methiodide is similarly prepared.  Specifications 232,740, 334,706, [both in Class 2 (iii)], 344,409, 351,555, 353,863, 456,534, and 506,720 also are referred to.