Patent GB-471743-A (GB)
Title: Improvements in the manufacture and production of vat dyestuffs
Filed: 1936-03-06
Abstract: Vat dyestuffs of the pyrazine series, of the general formula <FORM:0471743/IV/1> in which R is the radicle of an aromatic compound combined in adjacent positions with the nitrogen atoms of the pyrazine ring, R1 is hydrogen or an organic radicle and R2 is an organic radicle, at least one of R, R1 and R2 being capable of being vatted, or <FORM:0471743/IV/2> in which a ring is attached at the linkages a, are manufactured by the action of organic amino compounds or secondary nitrogenous heterocyclic bases on Pz-dihydroxy- or Pz-halogen-hydroxyquinoxalines, the initial materials being so chosen that at least one of them is capable of being vatted.  The radicles R, R1 and R2 may belong to the anthraquinone, anthrapyrimidine, dibenzanthrone, isodibenzanthrone, anthraquinonebenzacridone or anthraquinonethioxanthone series, whilst one or two of them may alternatively belong to the benzene, naphthalene, anthracene, phenanthrene or benzanthrone series. These radicles may contain substituents, e.g. alkyl groups (such as methyl, ethyl or butyl) or halogen atoms (chlorine, bromine or fluorine) which may be in a side chain, e.g. in a --CF3 group.  When starting with Pz-dihydroxyquinoxalines it is advantageous to add condensing agents, e.g. zinc chloride, boric acid, sodium bisulphate or anhydrous copper sulphate.  In examples: (1) Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone is heated with aniline and nitrobenzene; the product dyes cotton brown-red shades; the aniline may be replaced by methylamine, ethylenediamine, o-, m- or p-toluidine, m- or p-chloraniline, 2 : 4-, 2 : 5-, 3 : 4- or 3 : 5-dichloraniline, 2 : 3 : 4- or 3 : 4 : 5-trichloraniline, 2-chloro-6-toluidine, o- or p-anisidine, a - or b  - naphthylamine, 1 - chloro - 2 - aminonaphthalene, p-phenylenediamine, 1- or 2-aminoanthraquinone, 1 - amino - 4 - methoxyanthraquinone, 1 - chloro - 2 - aminoanthraquinone, 1 : 4- or 1 : 5 - diaminoanthraquinone, 4 : 8-diaminoanthrarufin, 1-amino-4- or 5-benzoyl-aminoanthraquinone, cyclohexylamine, 8-aminoquinoline, methylaniline, 1-methylaminoanthraquinone, piperidine or pyrazolanthrone; (2) Pz-dihydroxy-1 : 2-pyrazinoanthraquinone is heated with p-chloraniline and anhydrous boric acid; (3) Pz-dihydroxy-1 : 2-pyrazinoanthraquinone is heated with aniline, anhydrous boric acid and diphenyl ether; (4) 2 : 3-dihydroxyquinoxaline is heated with 1-aminoanthraquinone, phosphorus oxychloride and nitrobenzene; the product dyes cotton salmon shades from a red vat; (5) Pz-dihydroxy-1 : 2-pyrazinoanthraquinone is heated with aniline in the presence of anhydrous sodium bisulphate, anhydrous copper sulphate or zinc chloride; (6) 2-chloro-3-hydroxyquinoxaline is heated with 1- or 2-aminoanthraquinone and nitrobenzene; (7) 3-bromo-Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone is heated with 3 : 5-bis-trifluoromethylaniline and nitrobenzene; the product dyes cotton yellow shades; the first starting material may be replaced by Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone or its 3-chloro- or 3-methoxy-derivative, and the second by 4-chloro-3- or 6-trifluoromethylaniline, 3- or 4-trifluoromethylaniline, 2-chloro-5-trifluoromethylaniline, 2-methoxy-5-trifluoromethylaniline, 2-chloro-4 : 5-bis-trifluoromethylaniline, 2 : 4 - dimethoxy - 5 - trifluoromethylaniline, 3-trifluoromethyl-4-methylsulphoneaniline, 1 : 4-diamino - 2 : 6 - bis - trifluoromethylbenzene, 2 : 2<1>-diamino-4 - 4<1>-bis-trifluoromethyldiphenyl or 4-amino-3-trifluoromethyldiphenyl ether; (8) Pz - dihydroxy - 2 : 3 - pyrazinoanthraquinone is heated with nitrobenzene with gradual addition of m-toluidine and zinc chloride; the product dyes cotton red shades from a green vat; there may similarly be used Pz-dihydroxy-or Pz-halogenhydroxy-1 : 2- or 2 : 3-pyrazinoanthraquinones substituted in one or more of the positions 5, 6, 7 and 8 of the anthraquinone nucleus, e.g. the 6- or 7-chloro-, methyl- or methoxy - derivatives; (9) Pz - chlorhydroxy-1 : 2-pyrazinoanthraquinone is heated with p-aminodiphenyl and nitrobenzene; the product dyes cotton bluish red shades from a brown vat; the p-aminodiphenyl may be replaced by m-aminodiphenyl, 2- or 4-aminofluorene or 2-aminodiphenylene oxide; (10) Pz-chlorhydroxy-1 : 2 - pyrazinoanthraquinone is heated with 3 : 3<1>-diaminodiphenyl and nitrobenzene; the product dyes cotton red-brown shades; the 3 : 3<1>-diaminodiphenyl may be replaced by m-or p-phenylenediamine, m- or p-toluylenediamine, 2 : 5-dichloro-m-phenylenediamine, 4 : 4<1>- or 2 : 4<1>-diaminodiphenyl, 3 : 3<1>- or 2 : 2<1> - dimethyl - 4 : 4<1> - diaminodiphenyl, 2 : 2<1>- or 6 : 6<1> - dichloro - 3 : 3<1>-dimethyl - 4 : 4<1> - diaminodiphenyl, 2 : 2<1>- or 3 : 3<1> - dichloro - 4 : 4<1> - diaminodiphenyl, 2 : 2<1>-dimethyl-6 : 6<1>-diaminodiphenyl, 4 : 4<1>-dimethyl-2 : 2<1> - diaminodiphenyl, 3 : 3<1> - diaminoazoxybenzene, 4 : 4<1> - diamino - diphenyl ether, 3 : 3<1> - diaminodiphenylmethane or 3 : 4<1>-diaminophenylaziminobenzene; the Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone may be replaced by its 3-bromo-, 3-chloro-or 3-methoxy derivative; (11) Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone is heated with p-cyclohexylaniline; the product dyes cotton red shades; the p-cyclohexylaniline may be replaced by m- or o-cyclohexylaniline or 5- or 6-amino-1 : 2 : 3 : 4-tetrahydronahhthalene; (12) Pz-chlorhydroxy - 1 : 2 - pyrazinoanthraquinone is heated with 5-aminocoumarane and nitrobenzene; the product dyes cotton red-violet shades from a brown vat; the 5-aminocoumarane may be replaced by its 2-methyl-, 2-methyl-7-methoxy- or 2 : 7-dimethyl-derivative or by 2-methyl-7-aminocoumarane; (13) Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone is heated with 3-aminoacetophenone and nitrobenzene; the product dyes cotton orange shades from a brown vat; the 3-aminoacetophenone may be replaced by 4-aminobenzophenone, 4-amino-2-chlorobenzophenone, 4-amino - 2 - chloro - 4<1> - methylbenzophenone, 4-amino - 2 : 4<1>-dichlorobenzophenone, 2-amino-4 : 5-dimethylbenzophenone, 3 : 3<1>- or 4 : 4<1>-diaminobenzophenone or 4 : 4<1>-diamino-3 : 3<1>-dimethylbenzophenone; the Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone may be replaced by its 3-bromo-, 3-chloro- or 3-methoxy-derivative; (14) Pz - chlorhydroxy - 1 : 2 - pyrazinoanthraquinone is heated with 3-amino-6-chloropyridine and nitrobenzene; the product dyes cotton reddish orange shades from a brown vat; the 3-amino-6-chloropyridine may be replaced by 3 : 5-diaminopyridine; (15) Pz-dihydroxy - 1 : 2 - benzo - 3 : 4 - pyrazinoanthraquinone is heated with m-toluidine, zinc chloride and nitrobenzene; the product dyes cotton reddish blue shades from a brown vat; (16) 4 - amino - Pz - dihydroxy - 1 : 2 - pyrazinoanthraquinone is heated with aniline and dehydrated boric acid; the product dyes cotton red-violet shades from a red-brown vat. 1 : 2 : 3 : 4-Tetrahydroquinoline is also specified as a starting material. Specifications 361,097, 452,436 and 459,890 are referred to.  Pz-chlorhydroxy-1 : 2-pyrazinoanthraquinone is obtainable by heating dihydroxy-1 : 2-pyrazinoanthraquinone with phosphorus oxychloride in the presence of nitrobenzene. 2-Chloro-3-hydroxyquinoxaline is obtainable by heating 2 : 3-dihydroxyquinoxaline with phosphorus oxychloride.  Pz-dihydroxy-2 : 3-pyrazinoanthraquinone is obtainable by condensing 2 : 3-diaminoanthraquinone with oxalic acid. Substitution products thereof, together with the isomeric 1 : 2-pyrazinoanthraquinones, are obtainable by condensation of substituted phthalic anhydrides with chloro- or bromobenzene, nitration, replacement of halogen by amino, reduction of the nitro group, condensation with oxalic acid and ring closure to the anthraquinone.  The isomers may be separated by virtue of the different solubilities of their sulphates in moderately diluted sulphuric acid.  2 : 4 - Dimethoxy - 5 - trifluoromethylaniline is obtainable by treating 2 : 4-dichloro-5-trifluoromethyl-1-nitrobenzene with sodium methylate and reducing the nitro group.  3-Trifluoromethyl-4-methylsulphoneaniline is obtainable by treating 4-chloro-3-trifluoromethyl-1-nitrobenzene with the sodium salt of methanesulphonic acid and reducing the nitro group.  1 : 4-Diamino-2 : 6-bis-trifluoromethylbenzene is obtainable by nitrating 2 : 6-di-(o -trifluoro)-methylaniline and reducing the nitro group.  2 : 2<1> - Diamino - 4 : 4<1> - bis - trifluoromethyldiphenyl is obtainable by treating 2-chloro-5-trifluoromethyl - 1 - nitrobenzene with copper powder.  4 - Amino - 3 - trifluoromethyldiphenyl ether is obtainable by treating 4-chloro-2-trifluoromethyl-1-nitrobenzene with sodium phenolate and reducing the nitro group.  4-Aminofluorene is obtainable by nitration of 2 : 7 - dichlorofluorene and reduction with hydrogen under pressure in the presence of a nickel catalyst.  6 : 6<1>-Dichloro-3 : 3<1>-dimethyl-4 : 4<1>-diaminodiphenyl is obtainable by converting 4-chloro-6-nitro - 3 - toluidine to 6 : 6<1> - dichloro - 3 : 3<1>-dimethyl - 4 : 4<1> - dinitrodiphenyl and reducing the nitro groups.  5-Aminocoumarane is obtainable by nitrating coumarane, reducing the resulting mixture of 5- and 7-nitrocoumarane and separating the isomeric amino compounds by vacuum distillation. 2-Methyl-5- and 7-aminocoumarane are obtainable by ring closure of 2-allyl-4- and 6-nitrophenol respectively with hydrogen bromide in the presence of glacial acetic acid, and reduction of the nitro group.  2 : 7-Dimethyl-5-aminocoumarane is obtainable similarly from 2-allyl-4-nitro-o-cresol.  2 - Methyl - 5 - amino - 7 - methoxycoumarane is obtainable from o-eugenol by ring closure, nitration and reduction.  4-Amino-2-chloro-, -2-chloro-4<1>-methyl- and -2 : 4<1>-dichlorobenzophenone are obtainable by condensing 2-chloro-4-nitrobenzoylchloride with benzene, toluene and chlorobenzene respectively, and reducing the nitro group.  2-Amino-4 : 5-dimethylbenzophenone is obtainable similarly from the condensation product of 3 : 4 - dimethyl - 6 - nitrobenzoyl chl