One step diazotization coupling process

Claim 2

In a process for the preparation of a metal free azo pigment having at least two -CONH- groups per molecule and a molecular weight of at least 500, by diazotization of a diazotizable amino benzene with a diazotizing agent to form a diazo compound and coupling said diazo compound with a coupling compound, the improvement wherein the diazotization and coupling are performed in a simple operation without separation of the diazo compound, said process comprising admixing: a. a diazotizable amino benzene having no sulphonic acid groups b. a coupling component which is a 2-hydroxy-naphthalene-3-carboxylic acid phenyl or naphthyl amide, said component having no sulphonic acid groups, active methylene or tertiary nitrogen groups, and c. a diazotizing agent selected from the group consisting of alkyl nitrite, dinitrogen tetroxide, dinitrogen trioxide, nitrosyl chloride, nitrosyl bromide and sodium nitrite in an organic liquid selected from the group consisting of liquid aromatic hydrocarbons or liquid aromatic hydrocarbons which are substituted by halo, nitro or lower alkyl, said solvent containing at most 10% water, the amount of said organic liquid being such that a substantial portion either of the diazo component or of the said coupling component, or of both these reactants remains undissolved therein.

Claim 3

A process according to claim 1 wherein the diazotizable amine is selected from the group consisting of 2,4- and 2,5-dichloraniline, 2,4,5-trichloraniline, 2-chloro-4-nitraniline, 4-chloro-2-nitraniline, 2-methoxy-4-nitraniline, 4-methoxy-2-nitraniline, 2-aminobenzoic acid methyl ester, aminoterephthalic acid dimethyl ester and -diethyl ester, 4-methoxy-3-aminophenyl benzyl sulphone, 4-methyl-3-aminodiphenyl sulphone, 4-methoxy-3-aminobenzene sulphonic acid diethyl amide, 2-methoxy-5-methyl-4-aminobenzene sulphonic acid methyl amide, 2,5-dimethoxy-4-aminobenzoic sulphonic acid anilide, 2,5-dimethoxy- and 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'-chloranilide, 4-chloro-3-aminobenzoic acid-2'-methyl-5'-chloranilide, 4-chloro-3-aminobenzoic acid-2'4'- and -2'5'-dichloranilide, 4-chloro-3-aminobenzoic acid-2'4'5'-trichloranilide, 4-chloro-3-aminobenzoic acid-2'-methyl-3'-chloroanilide, 4-carbethoxy-3-aminobenzoic acid-2'5'-dichloranilide, 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 and 3,3'-dimethylbenzidine, and the coupling component is selected from the group consisting of 2-hydroxynaphthalene-3-carboxylic acid anilide, -4'-chloranilide, -3'-nitranilide, -2'-methoxyanilide, -2'-methylanilide, -2'3'-dimethylanilide, -2'4'-dimethoxy-5'-chloranilide, -2'5'-dimethoxy-4'-chloranilide, =2'-methyl-4'-chloranilide, -2'-methyl-4'-methoxyanilide, 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"-dichloranilide, 2-hydroxynaphthalene-3-carboxylic acid, 2-hydroxycarbazole-3-carboxylic acid, bis-(2'3'-hydroxynaphthoyl)-1,4-diaminobenzene, -1,4-diamino-2-chlorobenzene, -1,4-diamino-2-methyl-5-chlorobenzene, -benzidine, o-tolidine, -1,4-diamino-2,5-dimethoxybenzene, -1,4-diamino-2,5-dimethylbenzene, -1,4-diamino-2,5-dichlorobenzene, -1,4-diamino-2-methoxy-5-chlorobenzene, and -pp'-diaminodiphenyl ether.

Claim 4

A process according to claim 1 wherein the alkyl nitrite is a C 1 -C 8 alkyl nitrite.

Claim 5

A process according to claim 1 wherein the solvent is chlorobenzene, o-dichlorobenzene, benzene, toluene, xylene or nitrobenzene and the diazotizing agent is sodium nitrite.

Claim 6

A process according to claim 1 wherein the diazotizing agent is added to the suspension of coupling agent and amine.

Claim 7

A process according to claim 4 wherein the diazotizing agent is added to the suspension of coupling agent and amine.

Claim 8

A process as defined in claim 1 wherein an azo pigment of the formula ##SPC1## is prepared.

Claim 9

A process as defined in claim 1 wherein an azo pigment of the formula ##SPC2## is prepared.

Claim 10

A process as defined in claim 1 wherein an azo pigment of the formula ##SPC3## is prepared.

Claim 11

A process for manufacturing an azo pigment wherein 31.6g. 4-chloro-3-amino-benzoic acid-2'4'-dichloranilide and 29.5g. 2-hydroxy-naphthalene-3-carboxylic acid-2'4'-dimethylanilide are added to 71.0g. o-dichlorobenzene to form a mixture and then 60.0 g. of glacial acetic acid is added to the mixture; the mixture is cooled to 15°C and gaseous ethyl nitrite is added; the resultant pigment is heated and recovered by filtration.

Claim 12

A process for manufacturing an azo pigment wherein 31.6g. 4-chloro-3-amino-benzoic acid-2'4'-dichloranilide and 29.5g. 2-hydroxy-naphthalene-3-carboxylic acid-2'4'-dimethylanilide are added to 71.0g. o-dichlorobenzene to form a mixture and then 60.0 g. of glacial acetic acid is added to the mixture; the mixture is cooled to 15°C and gaseous ethyl nitrite is added; the resultant pigment is heated and recovered by filtration.