Process for producing o-cyano-phenyl and o-cyano-benzoisothiazolyl azo-p-aminobenzene dyes
United States Patent Hagen et al. Apr. 8, 1975 1 PROCESS FOR PRODUCING 2.570.024 10/1951 Charpentier 260/465 R C AND 3,452.076 6/1969 Mohr et al. 260/465 R O CYANO BENZ0ISOTHIAZOLYL 3.549.635 12/1970 Ott 260/465 R AZO-P-AMINOBENZENE DYES FOREIGN PATENTS OR APPLICATIONS [75] Inventors; Helmut Hagen Frank thal; 327,049 7/l9l4 Germany 260/465 Guenter Hansen; Ernst Schaffnen 484.992 3 1970 Switzerland 260/208 20th Of Ludwigshafen, all Of OTHER PUBLICATIONS erman y Migrdichian, The Chemistry of Organic Cyanogen [7 3] Assignee: Badische Anilin- &amp; Soda- Fabrik Compounds,&#34; 1947 12 D13 5 Akt1engesellschaft, Ludwlgshafcn, Gilman et al.. Organic Syntheses, coll. Vol. L 2nd Rhme, Germany ed., (1951), pp. 107-109, QD262072. [22] Filed: June 30, 1972 Primary Examiner-Henry R. Jiles [211 Appl&#39; 267970 Assistant Examiner-Robert W. Ramsuer Attorney, Agent, or Firm-Johnston, Keil, Thompson [30] Foreign Application Priority Data &amp; Shurtleff July 13. 1971 Germany 2134896 [57] ABSTRACT [52] 11.8. CI. 260/157; 260/158; 260/205;  
  260/206; 260/207; 260M071; 260/2O8 A process for the production of o-cyano-phenyl and 511 1111. C1 C09b 43/00 m&#39;P&#39;amimbemm dyes [58] Field of Search 260/208, 465 R. 205, 157 by replacing bmmine in P&#34; by the cyano group through reaction with a heavy metal [56] References Cited cyanide, particularly cuprous cyanide, in an aqueous UNITED STATES PATENTS medium and at elevated temperature. 2.195076 3/1940 Bruun et 111. 260/465 R 2 Claims N0 Drawing-S PROCESS FOR PRODUCING O-CYANO-PHENYL AND O-CYANO-BENZOISOTHIAZOLYL AZO-P-AMINOBENZENE DYES The invention relates to a process for the production of azo dyes containing cyano groups from azo dyes devoid of water-solubilizing groups which contain bromine atoms attached to an aryl or heterocyclic radical by reaction with heavy metal cyanides, preferably cuprous cyanide or compounds which form cuprous cyanide, wherein the reaction is carried out in water at elevated temperature.  
  Aryl radicals and heterocyclic radicals of aromatic nature in accordance with this invention which contain exchangeable halogen atoms are particularly phenyl l5 radicals. and also quasiaromatic heterocycles. as for example benzoisothiazolyl-l .2 or benzoisothiazolyl-Z.l radicals.  
  It is surprising that this replacement of bromine atoms by cyano groups should take place under the conditions of the process defined because the same dyes containing halogen are completely degraded when treated with alkali metal cyanides alone.  
  The replacement of halogen by cyano in azo dyes in an organic medium is known from the patent literature. for example German Published Specification No. 1544.563 and Swiss Patent Specification No. 484.992.  
  Because of the fact that the dyes to be used for the exchange have little or no solubility in water it is extremely surprising that the replacement of bromine by cyano can be carried out in many cases in aqueous suspension.  
  The new process is particularly suitable for the production of azo dyes containing cyano groups and having the formula (I):  
  l A-N=N-K (I) In this formula A is a substituted phenyl or benzoisothiazolyl radical in which the CN substituent is in the ortho position to the azo group and K is a N-substituted para-aminophenylene radical.  
  Dyes which correspond to the general formulae (1) and (Il):  
 CN Z  
  R r 0 1v N I\| N \R2 CN 2 1 /R O N N=N N R (II) in which Y is bromine, nitro or a radical of one of the formulae:  
  4 (i 3f? I 0 R s v R Z is hydrogen. methoxy or ethoxy;  
 R is hydrogen, methyl, chlorine.  
 acetylamino or propionylamino;  
 R is alkyl of one to four carbon atoms, hydroxyethyl,  
 cyanoethyl. benzyl. phenylethyl or y-acetylamino- P py R is alkyl of one to four carbon atoms or hydroxyethyl;  
 R&#34; is hydrogen, alkyl of one to four carbon atoms,  
 phenyl, methylphenyl, chlorophenyl, methoxyphenyl or dichlorophenyl;  
 R is methyl;  
 R is carbomethoxy or carboethyoxy; and  
 R and R together may be a benzene ring which may bear methyl, ethyl, methoxy or ethoxy as substituents;  
 may preferably be prepared according to the new process.  
  The following radicals are examples of suitable radicals other than those already specifically mentioned: for R: methyl. ethyl. n-propyl, isopropyl. n-butyl or isobutyl; for R methyl. ethyl, n-propyl. isopropyl. nbutyl or isobutyl.  
  Replacing bromine by cyano is particularly successful in the case of dyes which have electron-yielding groups in the coupling components and in which Y is a heterocyclic radical.  
  Suitable starting materials are compounds which contain a bromine atom instead of the cyano group.  
  The new process is advantageously carried out by suspending the starting dye in water if necessary with the addition of a wetting agent. adding cuprous cyanide or a compound which forms cuprous cyanide. and heating the whole to about to 180C. Preferred reaction temperatures are within the range from l 10 to 150C in which case superatmospheric pressure obviously has to be used. Agitated autoclaves are preferred as pressure vessels. The reactants are used in at least a ratio of l l, but an excess of cuprous cyanide of up to 50 percent is advantageous.  
 The reaction time is generally from 3 to 6 hours.  
  Conventional products such as adducts of ethylene oxide to alcohols or phenols may be used as wetting agents.  
  The following Examples illustrate the invention. In the following Examples parts and percentages are by weight unless otherwise stated.  
 EXAMPLE 1 27.5 parts of the dye 2.4-dinitro-6-bromoaniline 3-acetylamino-6-methoxy-N-B-cyanoethyl-N-B- hydroxyethylaniline is stirred in an autoclave with 5.0 parts of cuprous cyanide in 500 parts of water for 3 hours at C. After cooling, the contents of the autoclave are suction filtered and the residue is digested with 83 parts of a 10 percent sodium cyanide solution. The product is washed until the filtrate is neutral and colorless and then dried slightly at 40C at subatmospheric pressure. A dye is obtained which according to thin layer chromatography no longer contains starting dye and which dyes polyester cloth blue shades.  
 methoxy.  
 EXAMPLE 2 15.4 parts of the dye 2.o-dibromo-4-nitroaniline 3-diethylaminoacetanilide is stirred in an autoclave in 500 parts of water together with 30 parts of cuprous cyanide for hours at 120C. After the autoclave has been cooled and the produced has been suction filtered. the residue is stirred at room temperature with 400 parts of a 10 percent sodium cyanide solution. suction filtered. washed with water and dried at 50C at subatmospheric pressure.  
  A bluish black powder is obtained which according to a thin layer chromatogram no longer contains starting dye and which consists of about 70 to 80 parts of the 2.6-dicyano dye and to parts of the 6- monocyano dye. The reaction product dyes polyester cloth fast reddish blue shades by the HT method.  
 EXAMPLE 3 24.6 parts of the dye 5-bromo-7-nitro-4- aminobenzoisothiazole-l .2 3- diethylaminoacetanilide is heated with 500 parts of water and 12.5 parts of the cuprous cyanide for 3 hours at 120C in a rolling autoclave having a capacity of 2 liters. After cooling. the contents of the autoclave are suction filtered. stirred with a mixture of parts of 20 percent ammonia solution and parts of water for 1 hour. again suction filtered, washed until neutral and dried at 50C at subatmospheric pressure. A blue black powder is obtained which dyes polyester cloth fast blue shades according to the HT method.  
 . EXAMPLE 4 28.1 parts of the aminobenzoisothiazole l .2 methoxy-N-/3-cyanoethyl-N-B-hydroxyethylaniline is reacted together with 10.0 parts of cuprous cyanide and 500 parts of water for 5 hours in an autoclave at 120C. After the autoclave has cooled the contents are dye 5-bromo-7-nitro-4 suction filtered. the filter cake is stirred at room tem- EXAMPLE 5 29.6 parts of the dye 2-bromo-4-nitro-6-l5&#39;-(3&#39;-otolyloxidiazolyl-l &#39;.2&#39;,4&#39;)]-l-aminobenzene 3- diethylaminoacetanilide is stirred for 3 hours at 120C with 500 parts of water and 5.2 parts of cuprous cyanide in an autoclave. then cooled. a mixture of 40 parts of concentrated ammonia solution and 50 parts of water is added. the whole is stirred for 1 hour at room temperature. the dye is suction filtered and washed with water until the filtrate runs away colorless. The dye formed is dried at C at subatmospheric pres- 3-acetylamino-6- sure. The blue black powder obtained. which dissolves in dimethylformamide with a blue color. dyes polyester cloth very fast reddish blue shades.  
 EXAMPLE 6 25.8 parts of the dye 2-bromo-4-nitro-6-[5&#39;-(3- methyloxdiazolyl-l .2 &#39;,4 l -aminobenzene-- 3- diethylaminoacetanilide is stirred in 500 parts of water with 5.2 parts of cuprous cyanide for 3 hours at l 15C. The mixture is worked up according to Example 5 and a dark powder is obtained which dyes polyester fibers reddish blue shades of high fastness to heat setting.  
  Further dyes are set out in the following Examples; they are obtained analogously by reaction of the 2- bromoazo dyes with cuprous cyanide.  
 EXAMPLE 7 Starting product: 2-bromo-4-nitro-6-[5 3 isopropyloxdiazolyl-l &#39;.2 &#39;,4&#39; ]-aniline 3- diethylaminoacetanilide. End product:  
  0 H o N N=N N/ 2 5 2 c H 2 5 NHCOCH t4 3 CH c6 \CH 4 Reaction time: 5 hours. Temperature: 1 10C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 8 Starting product: ethyloxdiazolyl-l &#39;,2. bishydroxyethylamino-3-acetylaminobenzene. product:  
 N c a on CZHLLOH Reaction time: 3 hours. Temperature: C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 9 Starting product: 2-bromo-4-nitro6-[5 3 phenyloxdiazolyl-l ,2&#39;.4&#39; )]-aniline N-B- hydroxyethyl-N-ethyl-m-toluidine. End product:  
 Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: violet.  
 EXAMPLE Starting product:  
 2-bromo-4-nitro-6-l 5 3 &#39;-n- 5 propyloxdiazolyl-l .2 &#39;,4&#39; ]-aniline--- N-B- cyanoethyl-N-B-methoxyethyl-m-toluidinei End prod- Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: red violet.  
 EXAMPLE ll Starting product:  
  6 CN&#39; 00H o N N-N N/ CEHAOH c n on N NHcocH CH2-EH-CH5 Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: greenish blue.  
 Starting EXAMPLE 14 product: 2-bromo-4nitro-6-[ 5 3 2-bromo-4-nitro-6-l 5 3 &#39;-nbutyloxdiazolyl-l &#39;,2,4 ]-aniline N-B- carbomethoxyethyl-N-ethylaniline. End product:  
 dimethylaniline. End product:  
 Reaction time: 3 hours. Temperature: l20C. Shade on polyethylene glycol terephthalate: violet.  
 Starting EXAMPLE 15 product: 2-bromo-4-nitro-6-[ 5 3 35 ethyloxdiazolyl-l ,2&#39;.4&#39; )]-aniline N-B-methoxyethyl-N-ethylaniline. End product:  
 Reaction time: 3 hours. Temperature: l20C. Shade on polyethylene glycol terephthalate: red violet.  
 EXAMPLE &#39;12 Starting product:  
 2-bromo-4-nitro-6-l 5 3 &#39;-mmethoxyphenyl-oxdiazolyl-l .2,4&#39;)]-aniline N-B- hydroxyethyl-N-B-cyanoethylamino-3-acetylamino-6- methoxybenzene. End product:  
 CN OCH- OCH J 0 H 2N N=N N 2 5 CEHAOCHE Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: red violet.  
 EXAMPLE 16 Starting product: 2-brom0-4-nitro-6-l5-(3-diazolyll&#39;,2&#39;,4&#39; )]-aniline N,N-B-bishydroxyethyl-mtoluidine. End product:  
 Reaction time: 3 hours. Temperature: C. Shade on 60 polyethylene glycol terephthalate: greenish blue.  
 EXAMPLE 13 Starting product: 2-bromo-4-nitro-6-l 5 3 isobutyloxdiazolyll&#39;.2&#39;,4&#39;)]-aniline---- N,N-B-  
 bishydroxyethylamino-3-acetylamino-6- methoxybenzene. End product:  
  c a pn C H OH Reaction time: 3 hours. Temperature: C. Shade on polyethylene glycol terephthalate: violet.  
 Reaction time: 3 hours. Temperature: 130C. Shade on polyethylene glycol terephthalate: violet.  
 EXAMPLE 18 Starting product: 2-bromo-4-nitro-6-[ 5 3 isopropyloxdiazolyl-l &#39;,2,4&#39;)]-aniline- N-B- cyanoethyl-N-ethyl-m-toluidine. End product:  
  O N CH cH cH 3 Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: claret.  
 EXAMPLE 19 25.9 parts of the dye 2-bromo-4-nitro-6-[2-(thiazolyl-l &#39;,3&#39; ]-aniline-- 3-diethylaminoacetanilide is stirred in 500 parts of water and 5.1 parts of cuprous cyanide in an autoclave for 3 hours at 100C. The reaction mixture is cooled to room temperature and a mixture of 40 parts of concentrated ammonia and 50 parts of water is added. The whole is stirred for 1 hour and suction filtered. and the filter cake is washed with water until the filtrate is colorless and dried at 50C at subatmospheric pressure.  
  The dye thus obtained, which is a blackish powder. dissolves in dimethylformamide with a blue colour and dyes polyester cloth fast neutral blue shades.  
  The dyes set out in the following Examples are synthesized in an analogous manner:  
 EXAMPLE Starting product: 2-bromo-4-nitro-6-[5&#39;-(2,4- methylthiazolyl- 1 ,3 ]-aniline---- 3- diethylaminoacetanilide. End product:  
 Reaction time: 3 hours. Temperature: 1 10C. Shade on polyethylene glycol terephthalate: blue.  
  EXAMPLE 21 &#39;Starting product: 2- bromo-4-nitro-6-[2,4&#39;- methyl- 5&#39;-carbomethoxy-thiazolyl-1,3)]-aniline 3- diethylaminoacetanilide. End product:  
  c H o N N=N N/ 2 5 2 c H COCH  CH CH Reaction time: 3 hours. Temperature: 1 15C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 22 Starting product: 2-brom0-4-nitro-6-l 2 (benzothiazolyl-l ,3 )]-aniline --3- diethylaminoacetanilide. End product:  
 \ NHC OCH Reaction time: 3 hours. Temperature: 1 15C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 23 Starting material: 2-bromo-4-nitro-6-[2 5 methylthiadiazolyl-l ,3 ,4&#39; ]-aniline 3- diethylaminoacetanilide. End product:  
  N a 5 2 =N c H 2 5 COCH Reaction time: 3 hours. Temperature: 1 15C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 24 Reaction time: 4 hours. Temperature: 1 C. Shade of dyeing on polyethylene glycol terephthalate: blue.  
 EXAMPLE Starting product: 2-bromo-4-nitro-(w-l 2-( 5 isopropylthiadiazolyl-1&#39;,3&#39;,-l&#39;)]-aniline 3- diethylamilmacetanilide. End product:  
 Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: blue EXAM PLE 26 Starting product: 2-bromo-4-nitro-6-[2-(5&#39;- phenylthiadiazolyl-l ,3 ,4&#39; )]-aniline 3- diethylaminoacetanilide. End product:  
 \ NHCOCH CN OCH C H OH Reaction time: 2 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: green.  
 EXAMPLE 28 Starting product: 2-bromo-4nitro-6-l 5 2 methylthiadiazolyl-l &#39;,-3 .4 ]-aniline- N .N-B- bishydroXyethylamino-3-acetylaminobenzene. End productr N0 cn lg N c H on N=NQ N/ 2 4 c u on NHCOCH Reaction time: 3 hours. Temperature: C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 29 Starting product:2-bromo-4-nitro-o-l 5 2 butylthiadiazolyl-l ,3 ,4 )I-aniline 2-methoxy-5- acetylamino-N.N-B-bishydroxyethylaniline. End product:  
  NO N N C H CN OCH 9 5 c H OH 2 l N=N N C H OH NHCOCH Reaction time: 4 hours. Temperature: 120C. Shade on polyethylene glycolterephthalate: greenish blue.  
 EXAMPLE 30 Starting product: 2-brom0-4-nitro-6-[ 5 2 &#39;-pchlorophenylthiadiazolyl-1,3&#39;,4&#39;)]-aniline--- 3- diethylaminoacetanilide. End product:  
  No N-N (ll-Q4 CN H N=N N 5 HNCOCH Reaction time: 3 hours. Temperature: 1 10C. Shade on polyethylene glycol terephthalate; blue.  
 EXAMPLE 31 Starting product: 2-bromo-4-nitro-6-[ 5 2 methylthiadiazolyl-l &#39;,3 ,4 ]-aniline 2-methoxy-5- acetylamino-N-[3-cyanoethyl-N-B-hydroxyethylaniline. End product:  
  N N N OCH N 5/C2H4CN 5 N=N N\C2H4OH HNCOCH} Reaction time: 3 hours. Temperature: 120C. Shade on 1 polyethylene glycol terephthalate: greenish blue.  
 EXAMPLE 32 Starting product: 2-bromo-4-nitro-6-[5 2 ethylthiadiazolyll ,3 ,4 l-aniline 2-methoxy-5- acetylamino-N-B-hydroxyethylaniline. End product:  
  Starting product: 2-bromo-4-nitro-6-[ 5 2 phenylthiadiazolyl-l &#39;,3,4&#39; )]-aniline 3- acetylamino-N.N-B-bishydroxyethylaniline. End prod- Reaction time: 3 hours. Temperature: 120C. Shade on polyethylene glycol terephthalate: blue.  
  EXAMPLE 34 Starting product: 2-bromo-4-nitro-6-l 5 (2 butylthiadiazolyl-l ,3 ,4 ]-aniline- 2-methoxy- 5-acetylamino-N-/3-cyanoethyl-N-B- hydroxyethylaniline. End product:  
  N0 N.. N c a CN OCH C2H4CN N=N c H on 2 l HNcoca Reaction time: 3 hours. Temperature: C. Shade on polyethylene glycol terephthalate: turquoise.  
 EXAMPLE 35 Starting product;  
 chlorophenyl-thiadiazolyl-l ,3 ,4 )]-aniline 3- acetylamino-N.N-B-hydroxyethylaniline. End product:  
 HNCOCH Reaction time: 4 hours. Temperature: C. Shade on polyethylene glycol terephthalate: reddish blue.  
 EXAMPLE 36 Starting product: 2-bromo-4-nitro-6-[5 2 methylthiadiazolyl-l ,3 ,4 ]-aniline- 2-methoxy-5- acetylamino-N.N-B-bis-hydroxyethylaniline. End product:  
  C H OH HNCOCH Reaction time: 4 hours. Temperature: l l5C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 37 Starting product: 2-bromo-4-nitro-6-[5&#39;-(2- ethylthiadiazolyl-l ,3,4&#39; ]-aniline- N.N-B- bishydroxyethylamino-m-acetanilide. End product:  
 HNCO  
 Reaction time: 3 hours. Temperature: 130C. Shade on polyethylene glycol terephthalate: reddish blue.  
 EXAMPLE 3s 2-bromo-4-nitro-6-l 5 2 3- Starting product: butylthiadiazolyl-l ,3 ,4 ]-aniline diethylaminoacetanilide. End product:  
  No N N c n k CN N=N N/ 2 5 \C2H5 HNcocH Reaction time: 3 hours. Temperature: 140C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 39 Starting product: 2-bromo-4-nitro-6-[ 5&#39;-(2&#39;- 5 butylthiadiazolyl- 1 ,3 ,4&#39; ]-ani1ine--- N.N-B- bishydroxyethylamino-m-acetanilide. End product:  
  C H OH O HNC CH Reaction time: 3 hours. Temperature: 130C. Shade on polyethylene glycol terephthalate: reddish blue.  
  CN Z CN. Z N N=N 1-R or 0 N N=N N-R&#39; NO 2 2 r 2 Y R R R R N A l Br CN N-N /J2H5 2 5 in Which HNCOCH} Y is bromine. cyano, nitro.  
 R -C-N R I 3 i u i N R C or R -c C- \o/ \S s Reaction time: 3 hours. Temperature: 135C. Shade on 2 is hy OT ypolyethylene glycol terephthalate: blue. R hydrogen methyb chlorme- -Q&#39;- acetylamino or propionylamino. EXAMPLE R is alkyl of one to four carbon atoms, hydroxyethyl, Starting product; 2-br0mo-4-nitro-6-[2&#39;-(4&#39;- cyanocthyl, benzyl, phenylethyl or y-acetylaminobromophenyl-S&#39;-bromothiazo1yl-1&#39;,3&#39;)]-aniline N.- p py N-B bishydroxyethylaminoacetanilide. End product: R2 is alkyl O ne to four Carbon atoms or hydroxyethyl,  
  R is hydrogen, alkyl of one to four carbon atoms. NO phenyl. methylphenyl, chlorophenyl, methoxy- 2 phenyl or dichlorophenyl.  
  R is methyl. Br (3N R is carbomethoxy or carboethoxy and C H OH R and R taken together with the unsaturated linking N=N 2 4 carbon atoms form phenyl or phenyl substituted by H OH methyl, ethyl, methoxy or ethoxy.  
  2 4 said recess comprising reactin the same azo dye HNCOCH p g Reaction time: 3 hours. Temperature: C. Shade on polyethylene glycol terephthalate: blue.  
 EXAMPLE 42 Starting product: 2-bromo-4-nitro-6-l 2 4- bromophenyl-S -bromothiazo1y1-1,3 l-aniline 2- 14 methoxy-5-acetylamino-N-B-cyanoethyl-N-B- hydroxyethylaniline. End product:  
 N=N N CEHLLCN HNCOCH Reaction time: 3 hours. Temperature: 125C. Shade on polyethylene glycol terephthalate: green.  
 We claim: 1. A process for the production of an azo dye of the formula bearing bromine instead of cyano in ortho-position to the azo group with at least the equivalent amount up to an excess of 50 percent of cuprous cyanide at a temperature of from 70C. to 180C and in water.  
  2. A process as claimed in claim 1 wherein the reaction is carried out at a temperature of 1 10 to C.  
 under superatmospheric pressure.