CH668967A5 - METHOD FOR PRODUCING alkoxy-2-DIALKYLAMINOBENZOLDIAZONIUMSALZE. - Google Patents

Description

668 967

PATENT CLAIMS Process for the preparation of alkoxy-substituted 2-dialkylamino-benzenediazonium salts, characterized in that 2.3 dinitrohydroquinone dialkyl ethers of the general formula I

-NO, -NO,

I.

■ N2 X "

N

R '

R '

io in which R1, R2, R3 and Xe have the meaning given, diazotized, or by halogenating the 2-dialkylamino-3,6-dialkoxynitro-benzenes of the general formula III, the 2-dialkylamino-5-halogen-3,6-dialkyloxynitrobenzenes obtained general formula VI wherein R1 means alkoxy with ibis 6 carbon atoms with secondary 15

Amines of the general formula II

R "

-R '

HN

R '

H2N

^ \ R3

R4-

X *

II 20

-NO

^ / R

N

XR3

VI

R "

'R

wherein R2, R3 are identical or different alkyl having 1 to 6 carbon atoms,

Aralkyl having 1 to 4 carbon atoms in the alkyl radical, hydroxyalkyl having 1 25 in which R1, R2, R3 have the meaning given and R4 is chlorine to 6 carbon atoms, chloroalkyl having 1 to 6 carbon atoms, together or bromine, to the Corresponding amines of the general alkylene groups which are necessary for the completion of a 5- or membered heterocyclic formula VII ring which may contain a further heteroatom such as oxygen, sulfur or nitrogen, 30

Xe represents an anion, the resulting 2-dialkylamino-3,6-dialkoxy-nitrobenzenes of the general formula III are reacted

-NO,

/

R

■ N

III

-R "

35

40

VII

R

R

-NH3 X

■ N, No. wherein R1, R2 and R3 have the meaning given. 45

Reduced to the corresponding amines of the general formula IV and then to the 2-dialkylamino-5-halogen

3,6-dialkoxybenzene diazonium salts of the general formula VIII

2nd

o 50 k

Q

NH,

N

R

R

R '

'Rv

55

IV

R

VIII

N

-nh3 X

N '

.R '

'Rv wherein R1, R2, R3, R4 and Xe have the meaning given, 60 diazotized.

R "

65 DESCRIPTION

The invention relates to a synthesis process for the preparation reduced and then to the 2-dialkylamino-3,6-dialkoxy of substituted 2-dialkylaminobenzene diazonium salts, the benzene diazonium salts of the general formula V z. B. for the production of azo dyes and photosensitivity

3rd

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che components can be used in photographic or reprographic systems.

2-Dialkylamino-benzenediazonium salts are prepared by nitrating chloro- or bromobenzene and, after separating the isomeric nitro-halogenobenzenes, reacting 2-nitro-halogenobenzene with a secondary amine to give 2-dialkylamino-nitro-benzene, which is converted to 2-Dialkylamino-aniline is reduced and then diazotized to 2-dialkylamino-benzenediazonium ion (J. Prakt. Chem. 315, 725; 1973).

Furthermore, the 2-morpholino-5-methoxy-benzenediazonium salt is known (DE-PS1204 069). That is made

by nitrating p-acetaniside to 3-nitro-4-acetamido-anisole, which is saponified to 3-nitro-4-amino-anisole. This product is converted to 3-nitro-4-chloro-anisole by the SANDMEYER reaction and 3-nitro-4-morpholino-anisole is obtained from it by boiling with excess morpholine. Reduction of the nitro compound to 2-morpholino-5-methoxy-aniline and subsequent diazotization gives the 2-morpholino-5-methoxy-benzenediazonium salt. '

It is also known that an analogous nitration of 2,5-dialkoxychlorobenzenes exclusively to 2,5-dialkoxy-4-nitrochlorobenzenes (Ree. Trav. Chim 72,91; 1953) and the nitration of 2,5-dialkoxyacetanilides to 2.5 -Dialkoxy-4-nitro-acetaniliden leads (Ree. Trav. Chim. 72,178; 1953).

2,5-dialkoxy-6-nitrohalobenzenes or 2,5-dialkoxy-6-nitroacetanilides and thus the 2-dialkylamino-3,6-dialkoxybenzoldiazonium salts cannot be prepared by this generally known process.

The synthesis of 2-dialkylamino-5-halogenobenzenediazonium salts is known (DD-WP159 730). By nitrating p-dichloro- or p-dibromo-benzene, 2,5-dichloro- or 2,5-dibromo-nitro-benzene are obtained, which by nucleophilic exchange of the o-chlorine or o-bromine in 2-dialkylamino 5-chlorine or 2-dialkylamino-5-bromo-nitro-benzenes can be converted. The diazonium salts are then obtained by reducing the nitro group and then diazotizing the amine formed.

It is also known that analogous nitration of 2,5-dihalohydroquinone dialkyl ethers does not take place under mild conditions and that under drastic conditions the 2,6-diiodo-hydroquinone dialkyl ethers always lead to an exchange of the two halogen atoms by nitro groups (J. Chem. Soc. 109, 1087, 1916) and with the 2,5-dibromo or 2,5-dichloro derivatives leads to the elimination of the alkoxy groups, with 2,5-dibromo or. 2,5-dichlorobenzoquinones are formed (Mh. Chem. 45.71; 1924). 2,5-dialkoxy-3,6-dihalonitrobenzenes and thus the 2-dialkylamino-3-alkoxy-5-halogen-6-alkoxybenzene diazonium salts cannot be prepared by this generally known method.

The aim of the invention is to produce substituted 2-dialkylamino-benzene diazonium salts with alkoxy groups.

The invention is based on the object of creating a process for the preparation of substituted 2-dialkylaminobenzene diazo-nium salts with alkoxy groups from simple starting materials.

According to the invention the object is achieved in that 2,3-dinitrohydroquinone dialkyl ether of the general formula I

wherein R1 alkoxy means 1 to 6 carbon atoms, with secondary amines of the general formula II

.2

NM "

-R '

• R "

ffi

H2Î <

X1

II

* R "

io in which R2, R3 are the same or different alkyl having 1 to 6 carbon atoms, aralkyl having 1 to 4 carbon atoms in the alkyl radical, hydroxyalkyl having 1 to 6 carbon atoms, chloroalkyl having 1 to 6 carbon atoms, together those for completion 15 of a 5- or o-membered heterocyclic ring necessary alkylene groups, which may contain a further heteroatom such as oxygen, sulfur or nitrogen,

Xe is an anion, reacted, the 2-dialkylamino-3,6-dialkoxynitrobenzenes of the general formula III obtained

20th

R1

25th

-NO,

, R

3rd

III

30 wherein R1, R2 and R3 have the meaning given, to the corresponding amines of the general formula IV

35

40

45

50

-NH,

.N

R

Rev

IV

-NH,

-M

R

Rv reduced and then to the 2-dialkylamino-3,6-dialkoxy-benzenediazonium salts of the general formula V

55

1

-NO, -NO,

60

CT:

X

VR3

V

R "

I 65 wherein R \ R2, R3 and Xe have the meaning given, diazotized, or by halogenating the 2-dialkylamino-3,6-dialkoxynitro-benzenes of the general formula III, the 2-dialkylamino-5-halogen-3 obtained, 6-dialkoxynitrobenzenes of general

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my formula VI

VI

wherein R1, R2, R3 have the meaning given and R4 is chlorine or bromine, to the corresponding amines of the general formula VII

VII

a 2

-NH3 Xe M

<

R-

reduced and then to the 2-dialkylamino-5-halogen-3,6-dialkoxybenzene-diazonium salts of the general formula vm

R

-N2 x / R-3

R

VTII

Exemplary embodiments Example 1

a) 2,3-dinitrohydroquinone dimethyl ether 5 55.2 g (0.4 mol) of hydroquinone dimethyl ether are dissolved in 140 ml of glacial acetic acid. 140 ml of conc. Are stirred at 25-30 ° C. Nitric acid (D = 1.4) was added dropwise. The mixture is stirred for an hour and 500 ml of cold water are added. The product is filtered off, washed with water and dried. 10 The product is separated from the resulting 2,5-dinitrohydroquinone dimethyl ether by fractional crystallization from ethyl acetate.

A .: 60.5 g (66% of theory). Mp: 185-186 ° C

15

wherein R1, R2, R3, R4 and Xe have the meaning given, diazotized.

The 2,3-dinitro-hydroquinone dialkyl ethers are obtained in a known manner by dinitration of hydroquinone dialkyl ethers. The amino rank of 2,3-dinitro-hydroquinone dialkyl ethers is carried out under the conditions customary for this process.

In particular, morpholine, dimethylamine, pyrrolidine and piperidine are used as secondary amines. The 2-dialkylamino-3,6-dialkoxynitrobenzenes obtained are then reduced to the corresponding amines, e.g. diazotized by catalytic hydrogenation or by means of zinc dust and hydrochloric acid and according to known regulations by means of sodium nitrite or halogenated by means of bromine, chlorine gas, sulfuryl chloride or another known bromination or chlorinating agent. The subsequent reduction to the corresponding amines takes place. B. by catalytic hydrogenation or reduction using zinc dust and hydrochloric acid.

The amines are then diazotized using sodium nitrate in accordance with the known regulations. The diazonium compounds prepared in this way can be isolated as zinc chloride double salts, tetrafluoroborates or with other known anions as diazonium salts or can be reacted with known azo couplers to azo dyes.

b) 2-Dimethylamino-3,6-dimethoxy-nitrobenzene 45.6 g (0.2 mol) of 2,3-dinitro-hydroquinone dimethyl ether are dissolved in 200 ml of pyridine. The solution is mixed with 35 g NaHC03 and a solution of 33 g dimethylamine hydrochloride in 25 ml warm water and then boiled under reflux for 6 hours.

After cooling, the reaction solution is stirred with 800 ml of water, the product is filtered off with suction, washed with water and dried.

Crystallized from alcohol, light yellow crystals are obtained. 25 A .: 32.7 g (72% of theory). Mp .: 76-77 ° C

c) 2-Dimethylamino-3,6-dimethoxybenzoIdiazonium tetra-fluoroborate

3o 19.6 g (0.1 mol) of 2-dimethylamino-3,6-dimethoxy-aniline, which was obtained by catalytic hydrogenation of 2-dimethylamino-3,6-di-methoxynitrobenzene, are dissolved in 50 ml of concentrated hydrochloric acid and 30 ml of water dissolved. A solution of 7 g of NaNo2 in 30 ml of water is added dropwise at 0 ° C. while stirring and cooling. The mixture is stirred for 10 min and then a solution of 20 g NaBF4 in 50 ml water is added dropwise. With further cooling, stirring is continued for 2 hours, then the product is filtered off with suction, washed with cold water and dried. Dark red crystals are obtained.

A .: 19.2 g (61% of theory). Mp .: 128-130 ° C (dec.)

d) l-phenyl-3-methyl-4- (2'-dimethylamino-3,6'-dimethoxyphe-nylazo) -pyrazolone-5

The diazonium solution obtained under 1 c) is instead of 45 aqueous NaBF4 solution in a solution of 17.4 g (0.1 mol) of 1-phenyl-3-methylpyrazolon-5 in 100 ml of methanol and 50 ml of water, the 30 g of sodium acetate , 5 g of NaOH and 200 g of ice are added dropwise with stirring. It is followed up for 2 hours. stirred, washed with water and dried. A yellow azo dye is obtained in 50 quantitative yields.

e) 2-Dimethylamino-3-methoxy-5-bromo-6-methoxynitrobenzene

0.1 mol (22.6 g) of the 2-dimethyl prepared under 1 b)

amino-3,6-dimethoxy-nitrobenzene are dissolved in 250 ml of glacial acetic acid 55. A solution of 10 ml of bromine in 60 ml of glacial acetic acid is added dropwise at 20-25 ° C. with stirring. The mixture is stirred for 2 hours and then 200 ml of water are added. The precipitated product is suctioned off and dried.

A .: 30 g (98% of theory). Mp .: 98-99 ° C so After recrystallization from ethanol, analytically pure 2-dimethylamino-3-methoxy-5-bromo-6-methoxy-nitrobenzene (mp: 101 ° C).

f) 2-Dimethylamino-3-methoxy-5-bromo-6-methoxybenzene-65 diazonium tetrachlorozincate

0.05 mol (15.3 g) 2-dimethylamino-3-methoxy-5-bromo-6-methoxy-nitrobenzene are concentrated in 50 ml. Hydrochloric acid and 40 ml of water suspended. At 20 ° C (ice bath) with stirring

13 g of zinc dust are added in portions. If the reaction solution is colorless, it is filtered, the filtrate 10 ml conc. Hydrochloric acid was added and a solution of 3.5 g of sodium nitrite in 10 ml of water was added dropwise at 0-2 ° C. while stirring. Then 30 ml of cold saturated saline are added and stirring is continued for 1 hour. The reaction solution is stored in the refrigerator overnight, then the product is filtered off and washed with cold water. A .: 9.6 g (63% of theory). Mp .: 132-134 ° C (dec.)

g) l- (2'-Dimethylamino-3'-methoxy-5'-bromo-6'-methoxy-

phenylazo) -2-naphthol Soda is added to the diazonium salt solution obtained under 1 f) until all zinc has precipitated as zinc carbonate. The mixture is then filtered and the filtrate is added dropwise to a solution of 7.2 g (0.05 mol) of 2-naphthol in 70 ml of 10% aqueous NaOH with stirring and cooling. The mixture is stirred for 2 hours, suction filtered, washed with water and dried. A red azo dye is obtained in quantitative yield.

Example 2 a) 2-nitrohydroquinone diethyl ether 66.4 g (0.4 mol) of hydroquinone diethyl ether are dissolved in 500 ml of glacial acetic acid. 120 ml of dilute nitric acid (D = 1.24) are added dropwise with stirring at 20-25 ° C.

The mixture is stirred for 1 hour and 21 cold water are added. The product is filtered off, washed with water and dried.

A .: 82 g (97% of theory). Mp .: 45- ^ 7 ° C recrystallized from aqueous ethanol (1: 1 -V / V)) gives analytically pure 2-nitrohydroquinone diethyl ether (mp: 47-48 ° C).

c) 2,3-dinitrohydroquinone diethyl ether 84.4 g (0.4 mol) of 2-nitrohydroquinone diethyl ether are dissolved in 450 ml of glacial acetic acid. With stirring at 20-25 ° C, a mixture of 40 ml of conc. Nitric acid (D = 1.4) and 50 ml conc. Added dropwise sulfuric acid. The mixture is stirred for 30 minutes and then heated to 55 ° C. in a water bath. It is kept at this temperature for 15 min and then cooled to RT, suction filtered, washed with water and dried. A .: 89 g.p .: 128-133 ° C

The product is separated from the resulting 2,5-dinitrohydroquinone diethyl ether by fractional crystallization from ethanol.

A .: 53 g (52% of theory). Mp: 132-133 ° C

d) 2-morpholino-3,6-diethoxynitrobenzene 51.2 g (0.2 mol) of 2,3-dinitro-hydroquinone diethyl ether are boiled under reflux with 70 g of morpholine for 6 hours. After cooling, the reaction solution is stirred with 400 ml of water, the product which has precipitated is filtered off with suction and washed with water.

A .: 59 g (100% of theory). Mp .: 91-94 ° C. After recrystallization from ethanol, pure 2-morpholino-3,6-diethoxy-nitrobenzene is obtained (mp: 93-95 ° C.).

c) 2-Morpholino-3,6-diethoxybenzene diazonium tetrafluoroborate

The 2-morpholino-3,6-diethoxyaniline obtained by catalytic reduction of 2-morpholino-3,6-diethoxynitrobenzene is diazotized analogously to example 1 c) and isolated as tetrafluoroborate.

With a 0.1 mol approach, 29.2 g (80% of theory) of 2-morpholino-3,6-diethoxybenzene diazonium tetrafluoroborate are obtained.

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f) 2'-morpholino-3 ', 6-diethoxy-2,4-dihydroxyazobenzene The diazonium salt solution prepared under 2 e) is stirred and cooled to a solution of 11 g (0.1 mol) resorcinol in 120 ml 10% aqueous NaOH dropped. An orange dye is obtained in quantitative yield.

g) 2-morpholino-3-ethoxy-5-chloro-6-ethoxynitrobenzene 0.1 mol (29.6 g) 2-morpholino-3,6-diethoxy-nitrobenzene are dissolved in 240 ml of glacial acetic acid. Dry chlorine gas is passed into the reaction solution at 20-25 ° C. with stirring for 4 hours. The mixture is stirred for 2 hours and 300 ml of water and then 399 ml of 20% NaOH are added with stirring. The precipitated product is filtered off and washed with water.

A .: 31.8 g (96% of theory). Mp .: 92-95 ° C After recrystallization from ethanol, 2-morpholino-3-ethoxy-5-chloro-6-ethoxy-nitrobenzene (pure analysis) is obtained (mp: 97-98 ° C).

h) 2-Morpholino-3-ethoxy-5-chloro-6-ethoxy-nitrobenzene is catalytically hydrogenated and analogously from amine at 0 ° C

Example 1 c) diazotized. The diazonium salt is precipitated by adding cold saturated aqueous sodium tetrafluoroborate solution.

A .: 72% of theory Th. Mp .: 119-120 ° C (dec.)

i) 2- (2'-morpholino-3'-ethoxy-5'-chloro-6'-ethoxyphenylazo) -2,3-dihydroxynaphthalene 16 g (0.1 mol) 2,3-dihydroxynapthalene are dissolved in 100 ml 10% NaOH dissolved. Then, with vigorous stirring, acetic acid is added to the solution until the reaction is weakly acidic. The diazonium salt solution prepared under 1 h) is added dropwise to the resulting suspension with stirring and cooling. Aqueous sodium acetate solution is then added until an alkaline reaction occurs. The reaction mixture is kept slightly alkaline within 2 hours by further addition of aqueous sodium acetate solution in portions. It is then suctioned off, washed with water and dried. A red azo dye is obtained in quantitative yield.

Example 3

Analogously to Example 2, 2,3-dinitrohydroquinone diethyl ether is reacted with 70 g of piperidine.

57.6 g (98% of theory) of crude product with mp: 91-94 ° C. are obtained. After recrystallization from aqueous ethanol, analytically pure 2-piperidino-3-ethoxy-6-ethoxy-nitro-benzene (mp: 94-96 ° C.) is obtained.

0.1 mol (29.4 g) 2-piperidino-3,6-diethoxy-nitrobenzene are dissolved in 240 ml glacial acetic acid. 16.4 ml of sulfuric chloride in 40 ml of glacial acetic acid are added dropwise at 20-25 ° C. with stirring. The mixture is stirred for 4 hours and then 300 ml of water are added.

300 ml of 20% NaOH are then added. The precipitated product is filtered off and washed with water.

A .: 29.6 g (90% of theory). Mp .: 67-70 ° C

After recrystallization from ethanol, analytically pure 2-piperidino-3-ethoxy-5-chloroethoxy-nitrobenzene (mp: 71-73 ° C.) is obtained.

The piperidino-3-ethoxy-5-chloro-6-ethoxy-nitrobenzene is catalytically hydrogenated and the amine is diazotized at 0 ° C. in aqueous hydrochloric acid. The diazonium salt is precipitated by adding cold-saturated aqueous sodium tetrafluoroborate solution (A.: 77% of theory, mp: 104-106 ° C [dec.]) Or by adding the diazonium salt solution to a solution of 15 g of N, N-diethylaniline in 60 ml of glacial acetic acid and 700 ml of ice water containing 70 g of sodium acetate to obtain a brown dye in 80% yield.

5

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

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Example 4

Analogously to Example 1, hydroquinone dibutyl ether is dinitrated. The resulting mixture consists of approximately 1A of 2,5-dinitrohydroquinone dibutyl ether and 3A of 2,3-dinitrohydroquinone dibutyl ether. The crude product is reacted with morpholine analogously to Example 2, giving 2,5-dibutoxy-4-morpholinonitro-benzene and 2-morpholino-3,6-dibutoxynitrobenzene. This mixture is catalytically reduced in three times the amount of absolute alcohol using Raney nickel as a catalyst. The catalyst is then filtered off and 15 ml of concentrated HCl are added to the hot solution per 0.1 mol of starting product.

It is boiled again, then cooled and the precipitate formed is suction filtered.

In a 0.4 mol mixture, 77 g (62% of theory) of 2-morpholino-3,6-dibutoxyaniline hydrochloride (mp:

145-146.5 ° C). The resulting 2,5-dibutoxy-4-mor-pholinaniline dihydrochloride remains in solution.

Analogously to Example 1, the 2-morpholino-3,6-dibutoxyaniline hydrochloride can be diazotized and the diazonium salt can be precipitated in solid form or reacted with the couplers from Examples 1-3 to azo dyes.

Example 5

Analogously to Example 1, hydroquinone dibutyl ether is dinitrated. The resulting mixture of 2,5-dinitrohydroquinone di

Butyl ether and 2,3-dinitrohydroquinone dibutyl ether are separated from i-propanol by fractional crystallization.

Analogously to Example 2, 2,3-dinitrohydroquinone dibutyl ether (mp: 72-74 ° C.) is reacted with piperidine to give 2-piperidino-3,6-dibutoxynitro-5 benzene, which is then recrystallized from ethanol (mp: 70-72 ° C).

Analogously to Example 1, this product is reacted with bromine to give 2-piperidino-3-butoxy-5-bromo-6-butoxynitrobenzene, which is catalytically reduced with Raney nickel and is diazotized analogously to Example 1. A diazonium salt solution that contains 0.1 mol

Contains 2-piperidino-3-butoxy-5-bromo-6-butoxybenzenediazonium salt, is at 0 ° C to a solution of 26.3 g (0.1) 2-hydroxy-

3-naphthanilide in 120 mol of 10% NaOH and 60 ml of methanol was added dropwise with thorough stirring. The mixture is stirred for 2 hours,

15 sucks, washed with water and dried. A red dye is obtained in quantitative yield.

Example 6

20 Analogously to Example 2, 2,3-dinitrohydroquinone diethyl ether is reacted with pyrrolidine to give 2-pyrrolidino-3,6-diethoxynitrobenzene, which is catalytically reduced with Raney nickel and is diazotized analogously to Example 1. The diazonium solution obtained is coupled to 2-hydroxy-6-methoxy-3-naphth-o'-toluidide 25 analogously to Example 5, giving a blue azo dye.

M