GB1595498A - Process for the preparation of aromatic amines - Google Patents
Process for the preparation of aromatic amines Download PDFInfo
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- GB1595498A GB1595498A GB4736177A GB4736177A GB1595498A GB 1595498 A GB1595498 A GB 1595498A GB 4736177 A GB4736177 A GB 4736177A GB 4736177 A GB4736177 A GB 4736177A GB 1595498 A GB1595498 A GB 1595498A
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- acid
- chloroamine
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D295/00—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms
- C07D295/04—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms
- C07D295/12—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms
- C07D295/135—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms with the ring nitrogen atoms and the substituent nitrogen atoms separated by carbocyclic rings or by carbon chains interrupted by carbocyclic rings
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- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
A process for the preparation of substituted aromatic amines of the general formula (I) <IMAGE> where R1, R2, R3 and R4 are as defined in claim 1, by direct amination with N-chloramine in a redox-type system is characterised in that an aromatic compound 1-4-disubstituted with an ether group and an acylamino group are reacted with an N-chloramine in an acid reaction medium with a strong acid. Products of this type present considerable difficulties in synthesis by the traditional methods due to the complexity and low selectivity of the processes which lead to the formation of secondary amines and salts. This synthesis technique is instead accompanied by a strong activating effect on the amination and enhanced selectivity. The products thus obtained are of great interest in the field of fine chemicals and particulary in the field of dyes, where they represent basic intermediates for the synthesis thereof.
Description
(54) PROCESS FOR THE PREPARATION OF
AROMATIC AMINES
(71) We, AZIENDE COLORI NAZIONALI AFFINI ACNA S.p.A., of IQ Largo Guido Donegani, 20121 Milano, Italy, an Italian Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the preparation of substituted aromatic amines, specifically, amino-substituted anilides. It also relates to new anilides which the method of the invention makes easily accessible, and to azo dyes prepared from the substituted anilides.
The anilides are of general interest in the fine chemicals field and of particular interest as essential intermediates for the preparation of a range of azo dyes.
The anilides with which the invention is particularly concerned have the structure:
wherein R, and R2 are variously H, lower alkyl, cycloalkyl, cyanoalkyl, hydroxyalkyl or aralkyl (except that both R1 and R2 may not be H), or together form a chain which may or may not incorporate one or more hetero atoms and which may incorporate one or more substituents, Ra is hydrogen, alkyl, aralkyl, cycloalkyl, aryl, substituted alkyl or substituted aryl, and R4 is alkyl, substituted alkyl or cycloalkyl, the substituents on the alkyl, aralkyl or aryl in the case of R3 and R4 being (where present) optionally halo, nitro, hydroxy, nitrilo, amino, carboxy, the latter including carboxy derivatives such as carboxyamides, carboxy esters; and sulphoxy the latter also including sulphoxy derivatives such as sulphonamides, sulphonic esters and sulphonyl halides.
Products of this kind normally show considerable difficulties of synthesis when using established methods. Such methods are usually particularly complex processes involving a final alkylation with alkyl sulphate or alkyl halide, of the intermediate:
(compare in case R4=CH3, R3=CH3 Beilst. 13 II, 1341).
In fact, it is well known that the N-dialkylation of an aromatic amine is a process of low selectivity due to the simultaneous formation of the secondary amine and of the quaternary ammonium salt. In order to avoid this drawback, T. L.
Kruger et al. in J. Org. Chem 1975 40, 77 have suggested the use, in the case of various similar amines (methoxy-halo and nitro-anilines), of complete methylation to the quaternary ammonium salt followed by removal of the third methyl group by distillation in a current of steam in a strongly basic medium.
The method of alkylaminating aromatic materials with chloroamines in the presence of a reducing salt (ferrous, cuprous or titanous salt) in an acid reaction medium, has been described in U.S. Pat. No. 3,483,255, in which non-substituted aromatic compounds such as benzene, toluene or naphthalene or monosubstituted derivatives thereof are alkaminated; the aromatic material may also contain a heterocyclic nucleus of the quinoline type, but it must contain at least one aromatic ring.
It has now surprisingly been found by the Applicants that such alkamination technique can be applied successfully also to materials having a structure and a chemical behaviour markedly different from those described in the prior art.
Specifically, we have found it to be effective with certain 1:4 disubstituted benzenes where the dissimilar substituents nevertheless have a similar directing and activating effect towards the amination, a situation which one would expect to favour the formation of isomers, but which nevertheless is found to give high selectivity.
The invention consists in a process of alkaminating an aromatic material with an N-chloramine in the presence of a reducing salt and in an acid medium, in which the aromatic material is a 4-oxy anilide of the formula:
The process of this invention is of particular value as leading to the direct synthesis of a range of new compounds, themselves constituting a feature of the invention. These are in particular those compounds in which R1 and R2 are joined to form, with the attached N, a piperidino group, these new compounds having the structure:
Additional new compounds are those described in the following Examples 5, 13 and 14 having the structures:
The reaction medium may suitably comprise, in addition to a reducing salt such as a ferrous, cuprous or titanous salt forming a redox system with the chloramine reagent, a strong acid such as, for instance, trifluoroacetic acid or mixtures thereof with acetic acid. Suitable acid media include concentrated sulphuric acid, trifluoroacetic acid or mixtures thereof with a solvent, where the solvent may be, for example, water, methanol, acetic acid and where the strong acid is employed at a concentration by weight equal to at least 25% of the mixture.
Suitable temperatures range from 0 to 400, but the reaction is preferably at room temperature. The pressure is not critical and may conveniently be atmospheric. As examples of chloroamines there may be mentioned N-chloromethylamine, Nchlorodimethylamine, N-chloromethylethylamine, N-chloromethylbenzylamine and N-chloropiperidine and N - chloro - N - methylpiperazine.
The reaction gives particularly good results at temperatures between 0 and 40"C. The optimum molar ratios between the N-chloroamine and the aromatic substratum vary according to the products being prepared, but usually are from 1:3 to 3:1.
The molar ratio between catalyst (reducing salt) and N-chloroamine may suitably range from 1:1 to 1:100, but is preferably from 1:1.2 to 1:50.
The molar ratio between the acid medium and the anilide substratum is not critical.
The products of the process of this invention and, in particular, the new substituted anilides the subject of this invention, can be coupled in known manner to provide azo dyes of the general formula:
wherein R is the radical of a diazo component of the benzenic, naphthenic or heterocyclic series, more particularly in the case where R1, R2, R3 and R4 represent alkyl radicals (including the case where R3 and R4 join). A particularly valuable such dye has the structure:
formed from the product of the process of this invention where R1, R2, R3 and R4 are all methyl. This has excellent applicative characteristics for polyester fibres.
According to one convenient method of carrying out the present invention, a reaction vessel equipped with a stirrer, a tap funnel, a thermometer and a cooler, is charged in the following sequence:
A. Some of the chosen reaction medium,
B The selected aromatic substratum,
C. A solution of N-chloroamine in the acid reaction medium, and
D. The catalyst.
When sulphuric acid is employed at a high concentration, care should be taken that the temperature during the addition of the aromatic substratum and of the N
chloroamine solution, should be sufficiently low as to prevent the sulphonation of the substratum.
The catalyst is desirably added gradually and incrementally so controlling the evolution of HCI, to enable it to be absorbed, e.g. by bubbling through an alkaline solution.
On conclusion of HC1 evolution, the contents of the reactor are poured onto crushed ice, whilst stirring, and the unreacted starting product, if any, is recovered from the acid solution e.g. by extraction with a suitable solvent. After partial or total neutralisation, for instance with 30% caustic soda, the product may be solvent
extracted. The choice of solvent is determined essentially by the distribution coefficient of the anilide product between the solvent and the reaction medium; a wide choise is available from amongst, for example, esters, ketones, ethers, and aliphatic and aromatic chlorinated solvents.
After distillation of the solvent, one obtains the finished product, in general in a state of purity already useful for subsequent application.
In some cases it may be useful to subject the product to re-crystallization from a suitable solvent or to fractional precipitation suitably as the chlorhydrate, sulphate or phosphate.
The following Examples illustrate how the invention may be carried into effect. Where not otherwise indicated, the term "part" is to understood as expressed in units of weight. The yield is calculated on the quantity of Nchloroamine used.
EXAMPLE I
Into a reactor fitted with a stirrer and provided with cooling means, thermometer and a dropping funnel, there were charged 220 parts of concentrated
H2SO4, and, maintaining the temperature below 10"C, there were added 27 parts of phenacetine (para-acetylphenetidine). Whilst stirring, there were then charged 68.5 parts of a sulphuric acid solution of N-chloro-dimethylamine at a concentration of
17.4% corresponding to 11.9 parts of the chloramine. Thereupon, in portions, there were added 23 parts of FeSO4. 7 H2O.
The resulting mixture was allowed to react for I hour, after which the contents of the reactor were poured onto 500 parts of crushed ice.
After making somewhat alkaline with 30% NaOH, extraction with chloroform was carried out and the chloroform distilled off. There were thus obtained 27.7 parts of 4 - ethoxy - 3 - N,N - diethylamino - acetanilide with a titre of 91%. The yield amounted to about 76%.
The product precipitated as the hydrochloride, redissolved in water and, after being rendered alkaline, re-extracted with chloroform, has a titre of 99.2%, and a mpt. of 1l00-ll20C.
Similar results are achieved when using as a reaction medium 110 parts or 60 parts of concentrated H2SO4. The reaction proceeds at a similar rate and affords similar yields when quantities varying from 4.2 to 23 parts of Fez0,.7 H2O are used.
EXAMPLE 2
Proceeding generally as in Example 1, 74 parts of concentrated H2SO4, kept at below 10"C, were treated with 9 parts of phenacetine. Whilst stirring there were then added 23.8 parts of a sulphuric acid solution of N-chloro-piperidine of 25.1 /, strength, representing 6 parts of the chloramine. Then, portionwise, there were added 7 parts of FeSO4. 7 H2O.
The mass was allowed to react for 30 minutes, after which the contents of the reactor were poured onto 150 parts of crushed ice. Extraction was carried out with chloroform and the latter then distilled off. In this way 4 parts of unreacted phenacetine were recovered. The aqueous residue was then rendered somewhat alkaline and re-extracted with chloroform, the latter was distilled off and there were thus obtained 7.4 parts of 3 - piperidino - 4 - ethoxy - acetanilide, of the structure:
Titre: 93%, yield: 52%; melting point: 141.5"C--143.5"C.
EXAMPLE 3
Again following the general procedure of Example 1, the apparatus was charged with 73 parts of concentrated sulphuric acid and, whilst maintaining the temperature below 10 C, there were added 8.25 parts of N - acetyl - para anisidine. Whilst stirring, there were then added slowly 23.8 parts of a sulphuric acid solution of N-chloropiperidine of 25.1% concentration, representing 6 parts of the chloroamine. Portionwise, there were then added 7 parts of FeSO4.7 H2O, and the mixture was allowed to react for 1 hour.
Thereupon the contents of the reactor were poured onto 150 parts of crushed ice, and, after extraction with chloroform and distillation of the solvent there were recovered 2.7 parts of unreacted starting product.
The aqueous residue was then rendered somewhat alkaline with 30% NaOH and extraction was effected with chloroform. After distillation of the solvent, there were obtained 8.3 parts of 4 - methoxy - 3 - piperidino - acetanilide, of the structure:
Titre: 92%, yield: 62%; melting point: l560-l590C.
EXAMPLE 4
The procedure of Example 3 was followed, except that 19.4 parts of a sulphuric acid solution of N-chloro-dxrnethylamine at a concentration of 20.5%, representing 4 parts of the chloroamine, were substituted for the solution of N-chloropiperidine.
There were obtained 11 parts of 4 - methoxy - 3 - N,N - dimethylamino acetanilide.
Titre: 93.8%; yield; 99%; melting point: 109 111 C.
EXAMPLE 5
Into an apparatus as indicated in Example I there were charged 150 parts of concentrated H2SO4. Whilst maintaining the temperature below 10 C, there were then added 22.3 parts of paramethoxy-succinylanilic acid. The mixture was then kept stirred whilst adding 37.5 parts of a sulphuric acid solution of N - chloro dimethyl - amine at a concentration of 21.2%, representing 8 parts of the chloroamine. Then, portionwise, there were added 14 parts of FeSO4 .7 H2O, and the whole mass was kept stirred for 2 hours.
At the end of this time the contents of the reactor were poured onto 300 parts of crushed ice. Titrometric analysis showed the solution to contain 19.5 parts (a yield of 73%) of 4 - methoxy - 3 - N,N - dimethylamino - succinylanilic acid which, eluted on silicic acid, showed an R.F. of 0.3 with an eluent consisting of chloroform 70 parts, methanol 25 parts and 17.6 ammonia, 5 parts by volume. The product has the structure:
EXAMPLE 6
Into an apparatus as indicated in Example 1, there were charged 75 parts of concentrated H2SO4. Whilst maintaining the temperature below 10 C, there were added 9 parts of para-methoxy-propioanilide. Thereupon 19.1 parts of a sulphuric acid solution of N-chloro-dimethyl-amine at a concentration of 20.8%, representing 4 parts of the chloroamine, were added slowly. This was followed by the portionwise addition of 7 parts of FeSO4.7 H2O, the mixture being kept stirred for 2 hours.
After the two hours the contents of the reactor were poured onto 150 parts of crushed ice, and extracted with chloroform followed by distillation of the solvent, to recover 2 parts of unreacted starting product. The residue was made somewhat alkaline with 30% NaOH, extraction was carried out with chloroform and, after distillation, there were obtained 10 parts of 4 - methoxy - 3 - N,N dimethylamino - propioanilide.
Titre: 90.6 ; yield: 81.6%.
EXAMPLE 7
Into an apparatus similar to that of Ex. I, there were charged 74 parts of concentrated H2SO4. Whilst maintaining the temperature below 10"C, there were added 10 parts of 4-methoxy-chloroacetanilide. Then, whilst stirring, there were added 19.1 parts of a sulphuric acid solution of N-chloro-dimethyl-amine at a concentration of 20.8%, representing 4 parts of the chloroamine.
Finally, a portionwise addition was made of 7 parts of Fez0,.7 H2O and the whole mass was then allowed to react for 2 hours, after which the contents of the reactor were poured onto 150 parts of crushed ice.
Extraction was effected with chloroform and the solvent was distilled, to leave 3 parts of unreacted starting product. After rendering the aqueous residue somewhat alkaline with more chloroform, the solvent was distilled to give 10.7 parts of 4 - methoxy - 3 - N,N - dimethylamino - chloroacetanilide, of titre 86%.
The yield was 75.5%; the mpt. was 105"--107"C.
EXAMPLE 8
Into the apparatus of Example I there were charged 74 parts of concentrated
H2SO4, followed by 9 parts of 4-methoxy-hydroxyacetanilide whilst maintaining the temperature below 10 C. Then, whilst stirring, there were added 19.1 parts of a sulphuric acid solution of N-chloro-dimethyl-amine at a concentration of 20.8%, representing about 4 parts of the chloroamine. Finally, a portionwise addition was made of 7 parts of FeSO4. 7 H2O.
The resulting mixture was then allowed to react for 2 hours, after which the contents of the reactor were poured onto 150 parts of crushed ice. This was followed by extraction with chloroform and distillation of the solvent to give 0.6 parts of recovered, unreacted starting product.
After rendering the aqueous residue somewhat alkaline and extraction with chloroform distillation of the solvent (chloroform) gave the product, amounting to 8.9 parts of 4 - methoxy - 3 - N,N - dimethyl - amino - hydroxy - acetanilide. It had a titre of 93.7%; the yield was 74.5%.
EXAMPLE 9
Into an apparatus similar to that of Example 1, 74 parts of concentrated H2SO4 were charged. Whilst maintaining the temperature below 10"C, there were then added 11.3 parts of 4-methoxy-benzanilide followed, whilst stirring, by 19.1 parts of a sulphuric acid solution of N-CI-dimethylamine at a concentration of 20.8' > ^, representing about 4 parts of the chloroamine. Then, in discrete portions, there were added 7 parts of FeSO4. 7 H2O. The mixture was then allowed to react for 2 hours, after which the contents of the reactor were poured onto 150 parts of crushed ice. Extraction with chloroform and distillation of the solvent after rendering the reaction mass somewhat alkaline gave 11.5 parts of 4 - methoxy - 3
N,N - dimethylamino - benzanilide. Its titre was 95.5%; the yield was 81.4% and the mpt. was 1610--162.5"C.
By proceeding in the same way as in Example 3, the following products were
Example Yield m.p.
No. Formula % "C Chromatographies
40% - Eluted on silicic acid, it
shows an R.F. of 0.4 with
eluent:chloroform 70,
methanol 25, 17% ammonia
5 parts by volume.
UNITARY 73% - Elution on silicic acid, it
shows an R.F. of 0.2 with
eluent:benzene 79,
methanol 14, acetic acid
7 parts by volume.
UNITARY 50% 148 150 Elution on silicic acid, it
shows an R.F. of 0.3, with
eluent:benzene 79,
methanol 14, acetic acid
7 parts by volume.
UNITARY 60% - Eluted on silicic acid, it
shows an R.F. of 0.8 with
eluent:chloroform 70,
methanol 25, 17% ammonia
5 parts by volume.
UNITARY 56% - Eluted on silicic acid, it
shows an R.F. of 0.2 with
eluent:chloroform 70,
methanol 25, 17% ammonia
5 parts by volume.
UNITARY
WHAT WE CLAIM IS:
1. A process of aminating an aromatic substrate with an N-chloroamine in an acid medium in the presence of a reducing salt in which the substrate is a poxysubstituted anilide of the general formula (II) hereinbefore defined, to form an amino-substituted anilide.
2. A process according to Claim 1, in which the reactants are selected to give an aminated product of the general formula (I) hereinbefore defined.
3. A process according to Claim 1 or 2 in which the reaction medium comprises sulphuric acid and/or trifluoroacetic acid with or without acetic acid, and a reducing salt selected from ferrous, cuprous and titanous salts.
4. A process according to Claim 1, 2 or 3 in which the chloroamine is used in a molar ratio of from 1:3 to 3:1 with respect to the aromatic substrate.
5. A process according to any of the foregoing claims in which the reducing salt is ferrous sulphate and is used in an amount of from 1:1 to 1:100 moles per mole of N-chloroamine.
6. A process according to Claim 5, in which said amount is from 1:1.2 to 1:50 moles per mole of N-chloroamine.
7. A process according to Claim 1, substantially as set forth in any of the foregoing Examples.
8. A process according to Claim 1, in which the p-substituted anilide and Nchloroamine reagents are any of those hereinbefore specifically referred to.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (14)
- **WARNING** start of CLMS field may overlap end of DESC **.Example Yield m.p.No. Formula % "C Chromatographies40% - Eluted on silicic acid, it shows an R.F. of 0.4 with eluent:chloroform 70, methanol 25, 17% ammonia5 parts by volume.UNITARY 73% - Elution on silicic acid, it shows an R.F. of 0.2 with eluent:benzene 79, methanol 14, acetic acid7 parts by volume.UNITARY 50% 148 150 Elution on silicic acid, it shows an R.F. of 0.3, with eluent:benzene 79, methanol 14, acetic acid7 parts by volume.UNITARY 60% - Eluted on silicic acid, it shows an R.F. of 0.8 with eluent:chloroform 70, methanol 25, 17% ammonia5 parts by volume.UNITARY 56% - Eluted on silicic acid, it shows an R.F. of 0.2 with eluent:chloroform 70, methanol 25, 17% ammonia5 parts by volume.UNITARY WHAT WE CLAIM IS: 1. A process of aminating an aromatic substrate with an N-chloroamine in an acid medium in the presence of a reducing salt in which the substrate is a poxysubstituted anilide of the general formula (II) hereinbefore defined, to form an amino-substituted anilide.
- 2. A process according to Claim 1, in which the reactants are selected to give an aminated product of the general formula (I) hereinbefore defined.
- 3. A process according to Claim 1 or 2 in which the reaction medium comprises sulphuric acid and/or trifluoroacetic acid with or without acetic acid, and a reducing salt selected from ferrous, cuprous and titanous salts.
- 4. A process according to Claim 1, 2 or 3 in which the chloroamine is used in a molar ratio of from 1:3 to 3:1 with respect to the aromatic substrate.
- 5. A process according to any of the foregoing claims in which the reducing salt is ferrous sulphate and is used in an amount of from 1:1 to 1:100 moles per mole of N-chloroamine.
- 6. A process according to Claim 5, in which said amount is from 1:1.2 to 1:50 moles per mole of N-chloroamine.
- 7. A process according to Claim 1, substantially as set forth in any of the foregoing Examples.
- 8. A process according to Claim 1, in which the p-substituted anilide and Nchloroamine reagents are any of those hereinbefore specifically referred to.
- 9. A process according to Claim 8 in which the N-chloroamine reagent is Nchloropiperidine.
- 10. 3-Amino-4-oxy anilides when prepared by a process as set forth in any of the foregoing claims.
- 11. 3-Amino-4-oxy anilides conforming to the general formula (III) hereinbefore defined.
- 12. Anilides according to Claim 11, having the structure of the products of Examples 2, 3, 10,11 and 12.
- 13. 3-Amino-4-oxy anilides of the formula (IV), (V) or (Vl) hereinbefore defined.
- 14. Azo dyes formed by coupling to an anilide according to any of Claims l(w 14.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT2941776A IT1067024B (en) | 1976-11-17 | 1976-11-17 | PROCEDURE FOR THE PREPARATION OF AROMATIC AMINES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1595498A true GB1595498A (en) | 1981-08-12 |
Family
ID=11226944
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4736177A Expired GB1595498A (en) | 1976-11-17 | 1977-11-14 | Process for the preparation of aromatic amines |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5363331A (en) |
| BE (1) | BE860921A (en) |
| CA (1) | CA1092124A (en) |
| CH (1) | CH629745A5 (en) |
| DE (1) | DE2750951A1 (en) |
| ES (1) | ES464205A1 (en) |
| FR (1) | FR2397393A1 (en) |
| GB (1) | GB1595498A (en) |
| IT (1) | IT1067024B (en) |
| NL (1) | NL7712428A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2134130A (en) * | 1983-01-21 | 1984-08-08 | Yorkshire Chemicals Ltd | Disperse azo dyes |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL6717121A (en) * | 1965-10-29 | 1968-06-28 | ||
| NL7800026A (en) * | 1977-01-07 | 1978-07-11 | Acna | PROCESS FOR THE PREPARATION OF SUBSTITUTED AMINO-BENZENES. |
-
1976
- 1976-11-17 IT IT2941776A patent/IT1067024B/en active
-
1977
- 1977-11-11 NL NL7712428A patent/NL7712428A/en not_active Application Discontinuation
- 1977-11-14 CH CH1389577A patent/CH629745A5/en not_active IP Right Cessation
- 1977-11-14 JP JP13579077A patent/JPS5363331A/en active Pending
- 1977-11-14 GB GB4736177A patent/GB1595498A/en not_active Expired
- 1977-11-15 DE DE19772750951 patent/DE2750951A1/en not_active Withdrawn
- 1977-11-16 CA CA291,029A patent/CA1092124A/en not_active Expired
- 1977-11-16 ES ES464205A patent/ES464205A1/en not_active Expired
- 1977-11-16 FR FR7734444A patent/FR2397393A1/en not_active Withdrawn
- 1977-11-17 BE BE182695A patent/BE860921A/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2134130A (en) * | 1983-01-21 | 1984-08-08 | Yorkshire Chemicals Ltd | Disperse azo dyes |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2750951A1 (en) | 1978-05-18 |
| FR2397393A1 (en) | 1979-02-09 |
| CH629745A5 (en) | 1982-05-14 |
| ES464205A1 (en) | 1978-07-16 |
| JPS5363331A (en) | 1978-06-06 |
| BE860921A (en) | 1978-05-17 |
| IT1067024B (en) | 1985-03-12 |
| NL7712428A (en) | 1978-05-19 |
| CA1092124A (en) | 1980-12-23 |
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