One step process of preparing azo dyes by simultaneous diazotization and coupling at low pH

Claim 2

PROCESS FOR THE PRODUCTION OF A METAL-FREE AZO COMPOUND CONTAINING NO SULPHONIC ACID GROUPS BY DIAZOTISATION AND COUPLING IN ORGANIC SOLVENTS, WHICH CONSISTS ESSENTIALLY OF ADDING A C1 TO C10 ALKYL NITRITE AT A TEMPERATURE BETWEEN -50*C AND +100*C, TO AN ANHYDROUS REACTION MIXTURE CONSISTING OF A DIAZOTISABLE PRIMARY AMINO-BENZENE, A COUPLING COMPONENT, A C2 TO C6 A-HALOGENATED ALKANOIC ACID HAVING A PKAVALUE SMALLER THAN 3.0 IN AN AMOUNT OF 0.05 TO 0.5 MOLES OF SAID ACID RELATIVE TO 1 MOLE OF SAID AMINE, AND AN ORGANIC, NON-WATER-SOLUBLE SOLVENT HAVING A DIELECTRIC CONSTANT SMALLER THAN 15, OR A MIXTURE OF SUCH SOLVENTS.

Claim 3

Process according to claim 1 wherein the diazotisable amine is 2,4-dichloroaniline 2,5-dichloroaniline, 2,4,5-trichloroaniline, 2-chloro-4-nitroaniline, 4-chloro-2nitroaniline, 2-methoxy-4-nitroaniline, 4-methoxy-2-nitroaniline, 2-aminobenzoic acid methyl ester, aminoterephthalic acid dimethyl ester, aminoterephthalic acid diethyl ester, 4-methoxy-3-aminophenylbenzylsulphone, 4-methyl-3-aminodiphenylsulphone, 4-methoxy-3-aminobenzenesulphonic acid diethylamine, 2-methoxy-5-methyl-4-aminobenzenesulphonic acid methylamide, 2,5-dimethoxy-4-aminobenzenesulphonic acid anilide, 2,5-dimethoxy-4-benzoylaminoaniline, 2,5-diethoxy-4-benzoylaminoaniline, 2-methoxy-5-methyl-4-benzoylaminoaniline, 4-ethoxy-3-aminobenzamide, 4-methoxy-3-aminobenzoic acid anilide, 4-methyl-3-aminobenzoic acid-2'',4''-dimethylanilide, 4-methyl-3-aminobenzoic acid-4''-chloroanilide, 4-chloro-3-aminobenzoic acid-2''-methyl-5''-chloranilide, 4-chloro-3-aminobenzoic acid-2'',4''-dichloroanilide, 4-chloro-3-aminobenzoic acid-2'',5''-dichloranilide, 4-chloro-3-aminobenzoic acid-2'',4'',5''-trichloroanilide, 4-chloro-3-aminobenzoic acid-2''-methyl-3''-chloroanilide, 4-carboethoxy-3-aminobenzoic acid-2'',5''-dichloroanilide, 4-chloro-3-aminobenzoic acid, 4-methoxy-3-aminobenzoic acid, 4-methyl-3-aminobenzoic acid, 3,3''-dichlorobenzidine, 2,5,2'',5''-tetrachlorobenzidine, 3,3''-dimethoxybenzidine, or 3,3''-dimethylbenzidine, and the coupling component is 2-hydroxynaphthalene-3-carboxylic acid anilide, 2-hydroxynaphthalene-3-carboxylic acid-4''-chloranilide, 2-hydroxynaphthalene-3-carboxylic acid-3''-nitroanilide, 2-hydroxynaphthalene-3-carboxylic acid-2''-methoxyanilide, 2-hydroxynaphthalene-3-carboxylic acid-2''-methylanilide, 2-hydroxynaphthalene-3-carboxylic acid-2'',3''-dimethylanilide, 2-hydroxynaphthalene-3-carboxylic acid-2'',4''-dimethylanilide, 2-hydroxynaphthalene-3-carboxylic acid-2'',4''-dimethoxy-5''-chloroanilide, 2-hydroxynaphthalene-3-carboxylic acid-2'',5''-dimethoxy-4''-chloroanilide, 2-hydroxynaphthalene-3-carboxylic acid-2''-methyl-4''-chloroanilide, 2-hydroxynaphthalene-3-carboxylic acid-2''-methyl-4''-methoxyanilide, 2-hydroxynaphthalene-3-carboxylic acid-1''-naphthylamide, 2-hydroxynaphthalene-3-carboxylic acid-2''-naphthylamide, 2-hydroxycarbazole-3-carboxylic acid-4''-chloranilide, 6-(2'',3''-hydroxynaphthoylamino)-2,4-dioxotetrahydroquinazoline, 5-(2'',3''-hydroxynaphthoylamino)-benzimidazolone-(2), 1-(2'',3''-hydroxynaphthoylamino)-2-methoxy-5-chloro-4-benzoyl-aminobenzene, 3-(2'',3''-hydroxynaphthoylamino)-4-chlorobenzoic acid-2'''',5''''-dichloroanilide, acetoacetic acid anilide, acetoacetic-2-chloroanilide, acetoacetic-2-methoxyanilide, acetoacetic-2,4-dimethylanilide, acetoacetic-2,5-diethoxy-4-chloroanilide, 5-acetoacetylaminobenzimidazolone(-2), 2-hydroxynaphthalene-3-carboxylic acid, 2-hydroxycarbazole-3-carboxylic acid bis-(2'',3''-hydroxynaphthoyl)-1,4-diaminobenzene, bis-(2'',3''-hydroxynaphthoyl)-1,4-diamino-2-chlorobenzene bis-(2'',3''-hydroxynaphthoyl)-1,4-diamino-2-methyl-5-chlorobenzene, bis-(2'',3''-hydroxynaphthoyl)-benzidine, bis-(2'',3''-hydroxynaphthoyl)-o-tolidine, bis-(2'',3''-hydroxynaphthoyl)-1,4-diamino-2,5-dimethoxybenzene, bis-(2'',3''-hydroxynaphthoyl)-1,4-diamino-2,5-dimethylbenzene, bis-(2'',3''-hydroxynaphthoyl)-1,4-diamino-2,5-dichlorobenzene, bis-(2'',3''-hydroxynaphthoyl)-1,4-diamino-2-methoxy-5-chlorobenzene, bis-(2'',3''-hydroxynaphthoyl)-4,4''-diaminodiphenyl ether bis-(acetoacetyl)-benzidine, bis-(acetoacetyl)-o-tolidine, bis-(acetoacetyl)-1,4-diamino-2,5-dichlorobenzene, bis-(acetoacetyl)-1,4-diamino-2-methyl-5-chlorobenzene, or terephthaloylbisacetic acid-di-(o-chlorophenylamide).

Claim 4

Process according to claim 1 wherein the Alpha -halogenated carboxylic acid, if having a pKa below 1.0 is employed in the amount of 0.05 to 2.0 moles per mole of amine or if having a higher pKa, then in an amount of 0.2 to 0.5 moles per mole of amine.

Claim 5

Process according to claim 1, wherein the reaction is performed at a temperature of 20* to 50*C.

Claim 6

Process according to claim 1, wherein tri- or dichloroacetic acid is used.

Claim 7

Process according to claim 1, wherein monochloroacetic acid is used.

Claim 8

Process according to claim 1, wherein aliphatic or aromatic, hydrocarbons or halogenated aliphatic or aromatic hydrocarbons are used as organic solvents.

Claim 9

Process according to claim 1, wherein a mixture is used consisting of an organic solvent having a boiling point below 90*C and an organic solvent having a boiling point above 130*C.

Claim 10

Process according to claim 1, wherein nitrous acid esters of primary or secondary alcohols having 1 to 3 carbon atoms are used.

Claim 11

Process according to claim 1, wherein gaseous methyl nitrite is used as the alkyl nitrite.

Claim 12

Process according to claim 1 wherein the diazotisable amine is 4-chloro-3-aminobenzoic acid-2'',4'',5''-trichloroanilide; the coupling component is 2-hydroxynaphthalene-3-carboxylic acid-1''-napthylamide, the organic solvent is 1,1,1-trichloroethene, 1,2-dichloroethane, chlorobenzene, O-dichlorobenzene, 1,2,4-trichlorobenzene or mixtures thEreof, the alkyl nitrite is methyl nitrite and the Alpha -halogenated carboxylic acid is trichloroacetic acid or trifluoroacetic acid.

Claim 13

A process according to claim 1 wherein the coupling component is 2-hydroxynaphthalene-3-carboxylic acid -2'',4''-dimethylanilide, the diazotisable amine is 4-chloro-3-aminobenzoic acid-2'',4''-dichloroanilide, the alkyl nitrite is methyl nitrite, the solvent is chlorobenzene and the Alpha -halogenated carboxylic acid is chloroacetic acid, dichloroacetic acid, perfluorobutyric acid or Alpha -bromoaprioeacid.

Claim 14

A process according to claim 1 wherein the diazotisable amine is 4-chloro-3aminobenzoic acid, the coupling component 2-hydroxynaphthalene-3-carboxylic acid, the solvent is xylene or methyl isobutylketone, the alkyl nitrite is isopentyl nitrite and the Alpha -halogenated carboxylic acid is trichloroacetic acid.