DE2334770A1 - PROCESS FOR THE COUPLING OF NON-WATER-SOLUBLE 2,4-DISUBSTITUTED PHENOLS WITH DIAZOTATED O-NITROANILINES - Google Patents

Description

CiBA-GEIGY AG. CH-4002 Basel _

Oasis 3-8284

Dr. F. Zumstein Sr. - Dr. E. Assmann Dr. R. Koenigsboiger - Dipl. Ph ys. R. Holzbauer

Dr. F. Zumstein jun. Patent attorneys

8 Mönchen 2, Bräuhausstraße 4 / III

Process for coupling water-insoluble 2,4-disubstituted phenols with diazotized o-nitroanilines

The present invention relates to a process for the preparation of azo compounds by coupling of a diazotized o-nitroaniline and a water-insoluble?, 4-dl-substituted phenol.

409811 / 1U1

CIBA-GEIGYAG - 2 -

Due to the very low solubility of 2,4-disubstituted phenols in water and in aqueous solutions inorganic bases from pH 8 to 11, was previously the Coupling of such compounds only in the presence of water-miscible ones to carry out organic solvents such as alcohols, working in very dilute solutions so that the relative phenolate concentration required for a rapid course of the coupling was achieved , could be. Under such conditions, contaminated products resulted in relatively poor yields.

It has now surprisingly been found that

the coupling of 2,4-disubstituted phenols is possible with good yield if the phenol is dispersed in water and the reaction is carried out at a pH value less than 2. That was especially surprising as clutches of diazotized anilines with phenols in a strongly acidic medium preferentially with the formation of biaryls .

The new process has the advantage of good yield and high concentration

Diazo and coupling components in the reaction mixture too the preference, without organic solvents and without buffer ! mixes to work. This not only makes the process more economical but also reduces the risk of environmental pollution is becoming less.

409811/1141

CiBA-GEIGY AG

According to the new process, compounds of the formula I

(D

in the

1 R and R independently of one another are alkyl, cycloalkyl,

Aralkyl or chlorine

R ^{3 is} hydrogen, chlorine, alkyl, alkoxy, alkylsulfonyl, acylamino, -SO-Jl or -COOH

R is hydrogen or chlorine by reacting a diazonium salt of the amine of the formula II

(IX)

with a compound of the formula III

(in)

manufactured. The method is characterized in that a compound dispersed, preferably emulsified, in water

40981 1/1 HI

CIBA-GElGY AG -4 .-

of the formula III with a mineral acid solution of a diazonium salt the compound of the formula II is reacted in water at a pH value less than 2.

Compounds of the formula I are preferably prepared in which

] 2

R 'and Pv. independently of one another alkyl with 1 to 8 ■

Carbon atoms, cycloalkyl with 6 to 8 carbon atoms, aralkyl with 7 to 9 Carbon atoms or chlorine

R ^{3 is} hydrogen, chlorine, alkyl with 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, ethylsulfonyl, acetamino

-SCH or -COOH

Hydrogen or chlorine

mean.

12 3

By definition, R, R and R can be

be kyl groups. It can be methyl, ethyl, n ~ Propyl, iso-propyl, η-butyl, sec-butyl, tert-butyl, n-amyl, tert-arnyl, n-hexyl or tert-octyl. The groups

1 2

R and R also have the meaning of aralkyl, such as benzyl, α-methylbenzyl or α, α-dimethylbenzyl, or the meaning of cycloalkyl, such as cyclohexyl or cyclooctyl.

The phenols of the formula III are in the inventive Process as dispersions in water

A09811 / 1141

CiDA-GEIGYAG - 5 -

puts. Any fine distribution of the phenol, whether or not the phenol, is used as the dispersion in the present invention is liquid or solid, referred to. Dispersions are made, for example, by adding dispersants to the phenol, preferably to liquid phenol. Stirring often has to be done particularly quickly. It takes at According to the process according to the invention, however, not all of the phenol is present as a dispersion at the start of the reaction. It is quite possible that some of the phenol is in a separate form from the water, but with the water is in contact phase and only gradually dispersed in water during the reaction Form transitions. With some phenols it is therefore sufficient that a dispersant is present at the beginning of the reaction is. In the present application, therefore, the term "disperse phenols" also includes phenols, some of which are in a phase that is separate from the water but in contact with the water and are only partly dispersed in water. In the process according to the invention, preference is given to emulsions which means a fine distribution of liquid phenol in water.

The temperatures of the inventive

Process are preferably 0 to 60 ⁰ C, particularly preferably 20 to 40 ⁰ C. -

40981 1/1 UI

CIBA-GEIGYAG -O-

The pH of the reaction mixture should

always be below 2. If before the start of the reaction an amount of the sufficient to maintain this pH Mineral acid is submitted, then no pH control needs to be carried out. But if only with minimal amounts the mineral acid is used, the pH must be continuously monitored during the reaction and if necessary through Adding more mineral acid should be kept to a fourth less than 2.

Examples of dispersants which can be used according to the invention are dispersants from the list below (Ulimann, Encyklopadie der Technischen Chemie, third edition, Volume 16, 1965, pages 724-741). Is reproduced in the case of the anionic surfactants, the anion and in the case of the cationic surfactants the cation. In the case of anionic surfactants, the cation is generally an alkali ion, and the anion in the case of cationic surfactants mainly a chloride or methosulfate ion.

40981 1/1 141

CIBA-GEIGY AG

In the following list means

R is a long-chain alkyl radical

R ^{1 is} a short alkyl radical or H, and X is an alkylene radical, for example - (CH ^) - with n = 1-3

a) Salts of carboxylic acids 15-COO-Ιί-ΟΌΧΗ — X-COO " ¹ K

pcai-s

i \ - o — x — coo-ΙΪ — SX-COO-

—Coo-

If) Schvi-f.felsäureestcr

■ IV-CJi — X — C osor ^OR '

OSOi "

jt-oso- -. R — coo-CK ₃ ^ cjj-c:

OH

ΙΪ — COXII — X-OSO-

Jl-O-X-OSOi . c) alkyl sulfonates

-K '
I.

so-

CHj-COOIt -OaS-CII-COOK ItCOO-X-SO ₁ It-COX-X-SOi Jt '

Soap

MediGzkrlo Soaps »lit Zv.-iscl

Sulphaticrte ÖJa and Fclisnu ^ on Bulfnlioito ester

Sulfi.tierl-o amido

AHtylsuifcto Sulfalicrto FettEaureiuoiioglycoridc et al.

Sulphated to FcHsücrö-r.lkj-JoIftiiido BiiKnticrtti Atlicr

JSinforfio Alkylsulfoncve SuHbbernstetnEüureesler AlfcyHulfoaato luit intermediate links

409811/1141

SADORfGINAU

CLBA-GLiGY AG

d) Allcylarylsulfonntc ⁽ \ / \ / ^N so _i -

Alkylbcii7.o! Si;] fonnlo

C-) Surfactants with less common anionic groups

; Alkylphor-jriiato (verscliieilenorligo)

^ ^V0

¹¹ ov

Cooler surfactants

i. ») Amine salt i +

: K-NIT,

priinürc, Ec ': undfiic and

Amiiu: ~ i! Re>

K-COO-X-XUIi ₁ 'K-CONII-X-XHRJ

uid Urlip.ra

Ainins-alzo mil / iwis

K-Ο-Χ-NHR ₁ 'b) Quartz ammonium salts

K '

c) Pliosphonum salts

K '

K-Pi-R 'and

R '

(also njit Zwiscbouglifd ^ rn vie at dou Atn {malzon)

d) Sulfoniuiastvko

KS ⁺ . . R '

K'I

K — Ni-X-COO-

• A-

K '

R-Ni-X-SO, -K '

Botnine

• ·. 'ßulibbotoiuo

K '

Sulfntbotaino

A0981 1 / 1H1

BATHROOM 0RK31NAL

Ali

KieLiionogene TciiM-le-. . "

«) Älhyloioxydadduklc

11- (0-CIi ₂ -CHi) ₁₁ -OH AU: y1] .ü! YMhy] en _r , lyko! O

V- (O-CHj-CIIj) _n -OII A] ky] piK-: iylpo
K-CO (OC] I ₁ -CIIj) ₁₁ -OH acyl polyethylene glycol

JI- (O-CHj-CiIj) ₁₁ - (O-CH-CHj) _{13 - (O-CH 1} -CII,) ,, - OU oxalliylated! »Olypropyl uglycol CH ₃

l>) "Other nichfcioiiogeno surfactants \

K-COO -CH, -CII-CH, -OH Fetl5üxiii: noiioßlj-cer; 'Jo

OH

Κ — CONH-X-OH-R-COX - Χ — OH
^ X-OH

Fei tsiiui ep.Urvlolaniki3

II-COO-C ₁ -Hj ₁ Oj ₀ Sticchuroso-moiiofcttsaiircestcr

Those dispersants are preferred which stabilize the diazoniura salt through a "complex" formation (see S. Koller and H. Zollinger, Helvetica Chimica Acta Vol. 53, pages 78-89 (197O)). They are mainly aromatic compounds containing sulfo groups from the classes of alkyl and alkylarylsulfonates such as alkylbenzenesulfonates or alkylnaphthalene sulfonates. As concrete examples The following sulfonates (available as alkali or alkaline earth salts) are worth mentioning:

Benzenesulfonate, 1-naphthalene sulfonate, 2-naphthalene sulfonate, 1-tetralin sulfonate, 2-tetralin sulfonate, 1-naphthyl methanesulfonate, 2-naphthol-l-sulfonate,

409811/1141

CLBA-GEIGY AG - Ή) -

1,5-naphchhaline disulfonate, 2-naphthol-6,8-disulfonate, 2-naphthol trisulfonates or mixtures thereof.

The coupling is carried out in a mineral acid solution. Mineral acids come, for example Hydrochloric acid and sulfuric acid in question

In the method according to the invention, the Dispersion of the compound of the formula III was added to the solution of the diazonium salt of the compound of the formula II will. However, a solution of the diazonium salt of the compound of the formula II to form a dispersion is preferred given the compound of formula III. The preparation of the solutions of the diazonium salts of the o-nitroanilines Formula II is carried out in the manner known to the person skilled in the art.

^: In the method according to the invention

for example the diazonium salts of the following o-nitranilines are used:

^! 2-nitroaniline

; 2-nitro ~ 4-chloroaniline
2-nitro-4-methylaniline
2-nitro ~ 4-n-butylaniline
2-nitro ~ 4-tert-butylaniline
2-nitro-4-methoxyaniline

409811 / 1U1

C? 3A-GEIGY AG ~ IA ~

2 - nitro - 4,6 - dichloroaniline

2 - nitro - 4 - ethylsulfonylaniline

2 - nitro - 4 - acetylaminoaniline

3 - nitro - 4 - amitiobenzenesulfonic acid.

In the method according to the invention for example the following phenols are used:

2j4 - dimethylphenol

2,4 - di-isopropylphenol 2,4 - di-tert-butylphenol 2j4 - di - sec-butylphenol 2,4 - Di-tert-amylphenol 2,4 - Bis-a-phenylethylphenol 2,4 - Dicyclohexylphenol 2,4 - Dibenzylphenol

2 - methyl - 4 - tert. - butylphenol 2 - tert. - butyl - -4 - methyl phenol 2 - methyl - 4 - tert. - amylphenol 2 - tert. - amyl - 4 - methylphenol 2 - methyl - 4 - sec - butylphenol 2 - sec. - butyl - 4 - methylphenol 2 - sec. - butyl - 4 - tert. - butylphenol 2 - tert. - butyl -.4 - sec. - butylphenol 2 - methyl - 4 - α - phenylethylphenol

409811/1141

CfBAGSIGYAG - ·? <£ -

2 - α - phenylethyl - 4 - methylphenol 2 - α - phenylethyl - 4 - chlorophenol 2 - chloro - 4 - methylphenol 2 - methyl - 4 - chlorophenol 2 - chlorine - 4 - see. - butylphenol 2 - lake. - butyl - 4 - chlorophenol 2 - tert. - amyl - 4 - see. - butylphenol 2 - Cyclohexyl - 4 - roetlrylphenol 2 - CyeIoGet3 ^ 1 - 4 - methylphenol 2 - cyclohexyl - 4 - sec - butylphenol

2. - Cyclooctyl - 4 - see. - butylphenol 2 - α - phenylethyl - 4 - see. - butylphenol 2 - tert. - butyl - 4 - isopropylphenol 2 - tert. - amyl - 4 - isopropylphenol 2 - cyclohexyl - 4 - isopropylphenol 2 - chlorine - 4 · tert. - amylphenol 2 - chlorine - 4 - tert. - octylphenol 2 - see. - butyl - 4 - tert. - amylphenol 2 - tert. - amyl - 4 - see. - butylphenol 2 - benzyl - 4 - methylphenol 2 - methyl - 4 - benzylphenol 2 - tert. - octyl - 4 - methylphenol 2 - a, a - dimethylbenzyl - 4 - methylphenol 2 - methyl - 4 - α, α - dimethylbenzylphenol 2 - Sec. - butyl - 4 - tert. - octylphenol 2 - tert. - octyl - 4 - see. - butylphenol.

40981 1/1141

BATH

CLBA-GElGY AG - 13 -

^ 334770

The 2-

Nitranilines of the formula II are made according to known methods manufactured. For example, the corresponding 2-chloronitrobenzenes be reacted with ammonia to give the desired amines. Another manufacturing option is the o-nitration of acylated anilines with subsequent saponification of the amide group.

The phenols of the formula III which can be used as starting materials can also be prepared according to known methods Methods are made. One can, for example, phenol in the presence of acidic catalysts with olefins Dialkylate in the 2 and ^ positions. Another possibility of synthesis starts from 2- or 4-alkylphenols which can also be alkylated or chlorinated in the 4- or 2-position by known methods.

The compounds of formula I are intermediates for Benztriazble, which, as for example in Belgian Patent No. 563 210, find use as light stabilizers.

The following examples illustrate the invention. Percentages (%) are unless expressly stated otherwise designated, percentages by weight.

40981 1 / 1U1

CIBA-GLIGYAG

Procedure I.

Example I = coupling of o-nitroaniline with 2,4-di-tert.

butylphenol

D ia ζ ο I: GU η g: into a mixture of 130 g of ice and 264 g of sulfuric acid (. 92-947c) is slowly the temperature between 50 are entertainment and 60 ⁰ C, 130 g o-nitroaniline to. Once a solution forms, a total of a further 280 g of ice are added portionwise decreases vrobei the Teroperatur to about 10 ⁰ C and finely precipitates the amine. The mixture is then further cooled to 0-3 ° C., while maintaining this temperature, a 50% strength by volume solution of approx. 67.6 g of sodium nitrate is run in within 1 to 3 hours and the reaction is complete for 2-4 hours, a yellow solution being formed. At the end of the diazotization, a slight excess of nitrite should be detectable, otherwise further amounts of sodium nitrite must be added. Shortly before the start of the coupling, this excess is destroyed with sulfamic acid.

4 0 9 8 11/1141 ° * ®INAL

EiGYAG - 15

] S.HPElVÜ} aL First, 94 g of technical grade naphthalenesulfonic acid (mixture of isomers approx. 85 "L) in 80 g of water are added
60 ° C dissolved. 9.5 g are added with vigorous stirring
Alkyl aryl polyglycol ethers with alkyl aryl sulfonates (type Emullat P IAO HFP from Union Chimique Beige) and 191 g
molten 2,4-di- tert -butylphenol added and the suspension is stirred an hour to _s to form a homogeneous).! Emulsion. Then cool down to 40 ° C and leave the cold one
(0 - 5 ° C) run in the prepared Diazo solution within 2-3 hours. The reaction temperature is kept at 40-45 ° C. with a bath during the addition. After running in, the mixture is stirred for 6 to 10 hours at 40-43 ° C. until the diazo compound is completely depleted, then filtered through a suction filter and the coarsely crystalline product is washed with about 1.6 liters of warm water . After drying in vacuo at 70-75 ° C., 340 g of 90% product are obtained, which corresponds to a yield of 93% of theory
phenol used,. corresponds. Mp. 151 ° C.

If, instead of 2,4-di-tert-butylphenol, an equivalent amount of 2-chloro-4-methylphenol, 2,4-dimethylphenol, 2-sec-butyl-4-chlorophenol, 2-sec-butyl-4- tert-butyl phenol or 2-tert-butyl-4-see-butylphenol
and if you proceed as described, you get the following azo compounds:

40981 1/1141

2-nitro-2'-hydroxy-3'-chloro-5'-methylazobenzene, melting point 154 ° C. 2-nitro-2'-hydroxy-3 ', 5'-dimethylazobenzene, melting point 142 ° C. 2-nitro- 2'-hydroxy-3 ¹ -sec.-butyl-5-chlorazobenzene, m.p. 8U ° C 2-nitro-2'-hydroxy-3'-sec.-butyl-5 ⁱ tert.-butylazobenzene,

M.p. 94 ° C

2-nitro-2 '-hydroxy-3' -tert. -butyl-5 * -sec. -butylazobenzene,

M.p. 104 ° C

Example II = coupling of o-nitroaniline with 2,4-di-tert.

amylphenol

Diazotization: 215 g of water-containing 60% o-nitroaniline are added to 34 g of water and 30 g of ice and the mixture is stirred vigorously for 30 minutes. The resulting suspension is then poured into a solution of 300 g of hydrochloric acid (30%) and 120 g of ice. A 50% by volume solution of approx. 64.8 g of sodium nitrite is added within 3 hours and the temperature is kept between 0 and 5 ° C. by external cooling. The reaction mixture is left to react for 2-4 hours, a yellow solution being formed At the end of the diazotization, a slight excess of nitrite should be detectable, otherwise further quantities of sodium nitrite must be added. Shortly before the start of the coupling, this excess is destroyed with sulphamic acid.

4098 11 / 1U1

Coupling : First, 85 g of technical naphthalenesulfonic acid (mixture of isomers approx. 85%) are dissolved in 82 g of water at 60.degree. 8.6 g of alkylaryl polyglycol ether with alkylarylsulfonates (type Emullat P 140 HFP from Union Chimique Beige) and 206 g of molten 2,4-Ditert.amylphenol are added with vigorous stirring and the suspension is stirred for one hour until a homogeneous emulsion has formed . Then it is cooled to 35 ° C and the cold (0-5 ° G) prepared Diazq solution is allowed to run in within 4-5 hours. During the addition, the reaction temperature is kept at 36-38 ° C. with a bath. After the running-in has ended, the mixture is stirred for 3-10 hours at 40-45 ° C. until the diazo compound is completely consumed, then the product is filtered through a suction filter and washed with about 1.6 liters of warm water. After drying in vacuo at 70 ° C., 334 g of 90% product are obtained, which corresponds to a yield of 89% of theory, based on the phenol used. Mp. 125 ° C.

Used instead of 2,4-di-tert-amylphenol an equivalent amount of 2- <x-phenylethyl-4-chlorophenol, 2-cyclohexyl-4-methylphenol, 2-cyclohexyl-4-chlorophenol, 2-chloro - 4-tert. -octylphenol or 2-α-phenylethyl-4-methylphenol and if you proceed as described above, you get the following azo compounds:

40981 1/1141

2-nitro-2'-hydroxy-3'-a-phenylethyl-5'-chlorazobenzene,

M.p. 12A ° C

2-nitro-2'-hydroxy-3'-cyclohexyl-S ¹ -methylazobenzene,

M.p. 88 ° C

2-nitro-2'-hydroxy-3'-cyclohexyl-5'-chlorazobenzene,

Mp 96 ° C

2-nitro-2'-hydroxy-3'-chloro-5 ¹ -tert.-octylazobenzene,

Mp 137 ° C

2-nitro-2 '-hydroxy-3 ¹ -a-phenylethyl-5 ^1- methylazobenzene,

Mp. 123 ° C.

Example III = coupling of p-chloro-o-nitroaniline with

2 ~ tert-butyl-p-cresol

Diazotization: 241 g of water-containing 70% p- chloronitraniline are added to 293 g of initially charged sulfuric acid (92-94%) with cooling. The temperature is allowed to rise to 82 ° C., a solution being formed. Then a total of 514 g of ice are added in portions and the suspension obtained is stirred for 30 minutes, cooled to 0 ° C and, while maintaining this temperature, a 50% by volume solution of 70 g of sodium nitrite is added within 2-3 hours. The mixture is left to react for a further 2-4 hours and it is checked that there is always a slight excess of nitrite. The yellow diazo solution obtained is stored at 0-5 ° C. Shortly before the start of the coupling, the excess nitrite is destroyed with sulfamic acid.

40981 1/1 141

Coupling: 98 g of naphthalenesulfonic acid (technical isomer mixture approx. 85%) are dissolved in 84 g of water at 60.degree. To this are added under vigorous stirring, 9.8 g of alkylaryl polyglycol ether with alkylaryl sulfonates (type P 140 Emullat HFP from Union Chimique Beige) and 157.5 g of molten 2-tert-butyl-p-cresol, and the suspension is stirred at 60 ⁰ C for 2 hours until a homogeneous emulsion has formed. The emulsion is then cooled to 40 ° C., the cold, prepared diazo solution is allowed to run in within 2-3 hours and the reaction temperature is maintained with a bath at 40-45 ° C. during the addition. After the run-in has ended, the mixture is kept at for one hour 45 ° C, then heated to 60 ° C and kept at this temperature until the diazonium salt is completely consumed. The product is then filtered on a suction filter and washed with approx. 2 liters of warm water. Is obtained after drying at 80 ° C in vacuo 300 g 9Ö7 _o pure product, corresponding to a yield Voxi about 81% of theory, based on phenol, corresponding to "mp 172 ° C.

If, instead of 2-tert-butyl-pcresol, an equivalent amount of 2-a-phenylethyl-4-methylphenol is used, 2-chloro-4-methylphenol, 2,4-di-tert-amylphenol, 2-chloro-4-tert <-octylphenol or 2-sec.-butyl-4-tert.-butylphenol and if you proceed as described above, the following azo compounds are obtained:

40981 1/1141

CIBA-GEIGYAG - TO -

2 ~ nitro-4-chloro-2'-hydroxy-3'-a-phenylathyl-5'-methylazobenzol, mp. 154 ⁰ C

2-nitro-4-chloro ~ 2 '-hydroxy-3 ¹ -chlor-5 ¹ -methylazobenzene,

Mp 168 ° C.

2-nitro-4-chloro- ^{2'-hydroxy-3 1} , 5'-di-tert. -amylazobenzene,

Mp 114 ° C.

2-nitro-4-chloro- ^{2'-hydroxy-3 1} -chloro-5 ¹ -tert. -octylazobenzene, m.p. 144 ° C.

2-nitro »4-chloro-2 ^l -hydroxy-3'-see-butyl-5 ¹ -tert-butylazobenzene, melting point 125-126 ° C.

Example IV: = coupling of p-chloro-o-nitroaniline with

2,4-Ditert.buLylphenol

Diazotization: 220 g of water-containing 70% p- chloronitraniline are added to 264 g of initially charged sulfuric acid (92-94%) with cooling. The temperature is allowed to rise to 82 ° C., a solution being formed. A total of 453 g of ice are then added in portions, the suspension obtained is stirred for 30 minutes, cooled to 0 ° C. and, while maintaining this temperature, a 50% by volume solution of 64 g of sodium nitrite is added over the course of 2 to 3 hours. The mixture is allowed to react for a further 2-4 hours and it is checked that there is a slight excess of nitrite. The yellow diazo solution obtained is stored at 0-5 ° C. Shortly before the start of the coupling, the excess of nitrite becomes destroyed with sulfamic acid.

4 0 9 8 11/114 1

CIBA-GEIGYAG

-L 9 ° S naphthalenesulfonic acid (industrial isomer mixture about 85 L ⁰⁾ are dissolved in 156 g of water at 60 ° C. To this, 9 g of alkylaryl polyglycol ether with alkylarylsulfonates (type Eraullat P HFF from Union Chimique Beige) and 183/7 g of melted 2,4-di-tert-butylphenol are added under vigorous pounding and the suspension is stirred at 60 ° C. for about 2 hours until a has formed a homogeneous emulsion. The emulsion is then cooled to 40 ° C., the cold, prepared diazo solution is allowed to run in within 1 to 2 hours and the reaction temperature is kept at 40-45 ° C. with a bath during the addition. After the run-in has ended, the mixture becomes 2-4 Hours at 35 - 40 ° C until the diazonium salt is completely used up. The product is then sucked off and washed with approx. 2 liters of warm water. After drying in vacuo at about 80 ° C., 333 g of 90% strength product are obtained, which corresponds to a yield of about 86.5% of theory, based on the phenol used. Mp. 212 ° C.

Used instead of p-chloro-o-nitroaniline and 2,4-di-tert-butylphenol are those given below, respectively Starting materials and if the rest of the procedure is as described above, the following azo compounds are obtained:

4 0 9 8 1 1/1 U 1

CIB /'.- GEIGY AG - 22 -

From 3 - nitro ~ 4-aminobeiizolsul £ oic acid and 2,4-dimethylphenol 2-nitro-4 - sulfo-2 '-hydroxy-3 ¹ , 5' -dime.th3 ^r lazobenzene,

From 3 - nitro-4-aminobenzenesulfonic acid and 2,4-di-tert-butylphenol 2-nitro-4-sulfo-2 '-hydrox3'-3', 5 '-di-tert. buty lariobenxol,

From 2-nitrc-4-nie.thoxyan5.lin and 2,4-di-tert.-butylphenol 2 kit: ro-4-met.hoxy-2 '-hydroxy-3', 5 '-di-tert. -butylazobenzene. Mp- 160 ° C,

From 2-nitro-4-methoxyaniline and 2-scc.-butyl-4-tert.-butylphenol 2 Niltro-A-methoxy-Z ¹ -hydroxy-3 ¹ -sec.-butyl-5'-tert.-butylazobenzene, M.p. 93 ° C.

A0981 1/1 1

Claims (4)

ClPA-GEIGY AG Expectations \ .J Method of making connections of formula I. (I) in the 1 R and R independently of one another are alkyl, cycloalkyl, Aralkyl or chlorine R ³ hydrogen, chlorine, alkyl, alkoxy, alkyl sulfonyl, acylamino, -SO ^ H or -COOH 4th
R hydrogen or chlorine mean by reaction of a diazonium salt of the amine of the formula II, (II) with a phenol of the formula III (III) 40981 1 / 1H1 characterized in that a compound of the formula III dispersed in water with a mineral acid solution a diazonium salt of the compound of the formula II is reacted in water at a pH value of less than 2. 2. The method according to claim 1, characterized in that a mineral acid solution of a diazonium salt the compound of the formula II in water to a compound of the formula III emulsified in water at a pH value less than 2 is added. 3. The method according to claim 1 for the preparation of compounds of the formula I in which 1 ? R and R 'independently of one another are alkyl with 1 to 8 Carbon atoms, cycloalkyl with 6 to 8 carbon atoms, aralkyl with 7 to 9 Carbon atoms' or chlorine R hydrogen, chlorine, alkyl with 1 to 4 carbon " : carbon atoms, alkoxy with 1 to 4 coal ¹ atoms of substance, ethylsulfonyl, acetamino, : -SO, H or -COOH ^! i. S _i ; R hydrogen or chlorine i
mean. 40981 1/1 141