Patent GB-863164-A (GB)
Title: Improvements relating to fluorescent triazolyl stilbene compounds and their use
Filed: 1957-09-04
Abstract: The invention comprises triazolyl-cyanostilbene compounds of the formula:  <FORM:0863164/IV (b)/1> wherein A represents an aromatic carbocyclic radical which contains at most two rings, B represents a benzene or naphthalene radical in which two vicinal carbon atoms are bound to nitrogen atoms of the triazole ring, and n is either 0 or 1 with the proviso that A must contain a cyano substituent when n=o. The aromatic nuclei may be further substituted, but not by chromophores, auxochromes and other ionogenic substituents.  These compounds, which give rise to fluorescent solutions (see Group XL(a)) and are useful as brightening agents for fats, waxes and polymeric material (see Groups III, IV(a) and IV(c)), are produced by diazotising the appropriate 4-amino-cyanostilbene, reacting the diazo compound with an aromatic amino compound which couples in the neighbouring position to the amino group to produce an o-aminoazo dyestuff, and finally oxidising the dyestuff to the required triazolyl-cyano-stilbene.  In Example 1, a solution of 4-amino-2-cyanostilbene in dimethyl p  formamide, water and hydrochloric acid is diazotised; and the diazo compound is coupled with 2-aminonaphthalene dissolved in pyridine.  Sodium hydroxide and excess sodium chloride are then added.  The pyridine solution of the dyestuff is decanted, ice and dilute caustic soda are added, and an aqueous solution of sodium hypochlorite is then added dropwise. After stirring for several hours, the temperature is raised to 85 DEG -90 DEG C., sodium hydrosulphite is added, and the pyridine is distilled off with steam.  The crude product which precipitates is filtered off warm and washed with warm water.  It is then purified by dissolving in 50% aqueous dimethyl formamide, and precipitating with sodium chloride solution.  The product, i.e. 2-[211-cyanostibyl-411]-(naphtho -11, 21: 4, 5)- 1, 2, 3- triazole, is a pale yellowish powder having the structure  <FORM:0863164/IV (b)/2> Similar compounds may be prepared if the 2-amino-naphthalene is replaced by 2-aminomethoxynaphthalene wherein the methoxy group is in the 5, 6 or 7 position.  Example 2 describes the preparation of the compound having the structure <FORM:0863164/IV (b)/3> by diazotising 4-amino-2-cyano-stilbene, coupling the diazo compound 1-amino-4-methyl-5-methoxybenzene, and oxidising the dyestuff with sodium hypochlorite.  The 1-amino-4-methyl-5- methoxybenzene may be replaced by 1-amino-4-chloro-5-methoxybenzene, or 1-amino-4, 5-dimethoxybenzene, or 4, 41-diamino-2, 21-dimethoxydiphenyl.  In the latter case the product is 6, 6-bis-[5-methoxy-2-(21-cyanostilbene-41)- 1, 2, 3-benztriazole]. Example 3 describes the preparation of the compound having the structure <FORM:0863164/IV (b)/4> by coupling diazotised 4-amino-2-cyanostilbene with 1, 3-diaminobenzene, oxidising the resulting dyestuff with copper sulphate in aqueous pyridine solution which is strongly ammoniacal, and finally acetylating, with acetic anhydride, the 5-amino-2-(21-cyanostilbyl-41)-1, 2, 3-benztriazole. The latter compound may alternatively be treated with benzoyl chloride in order to obtain the corresponding benzoylamino derivative.  The 1, 3 diaminobenzene may be replaced by 4-methyl-1, 3-diaminobenzene, or 4-methoxy- 1, 3-diaminobenzene, or 4-chloro- 1, 3-diaminobenzene.  In Example 10, diazotised aniline is coupled with 5-amino-2-(21-cyanostilbyl-41)- 1, 2, 3-benztriazole (prepared as in Example 3), and the resulting dyestuff is oxidised with sodium hypochlorite to give the compound having the structure <FORM:0863164/IV (b)/5> The aniline may be replaced by 1-aminonaphthalene or by 2-aminonaphthalene.  Example 4 describes the preparation of the compound having the structure <FORM:0863164/IV (b)/6> by coupling diazotised 4-amino-2-cyano-21-methoxy-stilbene with 2-animonaphthalene, and then oxidising the dyestuff with sodium hypochlorite.  The 2-aminonaphthalene may be replaced by 1-amino-4-methyl-5-methoxybenzene.  The 4-amino-2-cyano-21-methoxystilbene may be replaced by 4-amino-2-cyano-41-methoxystilbene, 4-amino-2-cyano-41-methylstilbene, 4-amino-2-cyano- 31, 41-dehydroxy = methylenestilbene, 4-amino-2-cyano- 21-chlorostilbene, or 4-amino-2-cyano-41-chlorostilbene.  Examples 5 to 9 describe the preparation of compounds having the following structures:- <FORM:0863164/IV (b)/7> The starting materials, i.e. the 4-amino cyanostilbenes, may be prepared by reducing the corresponding 4-nitro compounds with iron filings in a mixture of ethylene glycol monomethyl ether and water.  The required nitro compounds may be prepared by condensing 4-nitro-2-cyano-1-methylbenzene with benzaldehyde or naphthaldehyde, or by condensing 4-nitrophenyl acetic acid with cyanobenzaldehyde.  Thus, 4-amino-2-cyano- 21, 31-benzostilbene is obtained by condensing 1-naphthaldehyde.  Thus, 4-amino-2-cyano- 21, 31-benzostiland other required cyanostilbenes are produced by replacing the naphthaldehyde by 2-methoxybenzaldehyde, or 4-methoxybenzaldehyde, or 4-methyl benzaldehyde, or 3, 4-dihydroxymethylene benzaldehyde, or 2- or 4-chlorobenzaldehyde, or 4-acetamino benzaldehyde.  As an example of the second method, 4-amino-41-cyanostilbene is prepared by condensing 4-cyanobenzaldehyde with 4-nitrophenyl acetic acid.  Specification 774,010 is referred to.ALSO:Dyestuffs are produced by diazotizing a 4-amino-cyanostilbene and then reacting the diazo compound with an aromatic amino compound which couples in the neighbouring position of the aromatic nucleus to the amino group.  When submitted to oxidation these dyestuffs yield fluorescent triazolyl stilbene compounds (see Group IV(b)) which are suitable for the brightening of polyester fibres.  In Example 1, a solution of 4-amino-2-cyanostilbene in dimethyl formamide and hydrochloric acid is diazotized, and the diazo compound is coupled with 2-aminonaphthalene dissolved in pyridine. Sodium hydroxide and excess sodium chloride are then added, whereupon a pyridine solution of the dyestuff forms a separate layer.  The 2-aminonaphthalene may be replaced by 2-aminomethoxynaphthalene wherein the methoxy group is in the 5-, 6- or 7-position.  Example 2 relates to dyestuffs produced by diazotizing 4-amino-2-cyano-stilbene and coupling the diazo compound with 1-amino-4-methyl-5 methoxybenzene, or 1-amino-4-chloro-5 methoxybenzene, or 1-amino-4, 5-dimethoxybenzene, or 4, 41-diamino-2, 21-dimethoxydiphenyl. Example 3 relates to dyestuffs produced by coupling diazotized 4-amino-2-cyano-stilbene with 1, 3-diaminobenzene, or 4-methyl-1, 3-diaminobenzene, or 4-methoxy-1, 3-diaminobenzene, or 4-chloro-1, 3-diaminobenzene.  In Example 10, diazotized aniline is coupled with 5-amino-2-(21-cyanostilbyl-41)-1, 2, 3-benztriazole (obtained by oxidizing the first dyestuff of Example 3).  The aniline may be replaced by 1-amino- or 2-amino naphthalene.  Example 4 relates to dyestuffs produced by coupling diazotized 4-amino-2-cyano-21-methoxy-stilbene with 2-aminonaphthalene, or 1-amino-4-methyl-5-methoxybenzene. Related dyestuffs can be produced by employing diazotized 4-amino-2-cyano-41-methoxystilbene, 4-amino-2-cyano-41-methylstilbene, 4-amino-2-cyano-31, 41-dihydroxymethylene stilbene, 4-amino-2-cyano-21-chlorostilbene, or 4-amino-2-cyano-41-chlorostilbene.  In Example 5, diazotized 4-amino-2-cyano-21, 31-benzostilbene is coupled with 2-aminonaphthalene.  In Example 6, diazotized 4-amino-41-acetamino-2-cyano-stilbene is coupled with 2-aminonaphthalene or with 1-amino-4-methyl-5-methoxybenzene.  In Example 7, diazotized 4-amino-41-cyano- (or 31-cyano-) stilbene is coupled with 2-aminonaphthalene.  In Example 8, diazotized 4-amino-2 cyano-stilbene is coupled with 5-amino-acenaphthene.  Related dyestuffs may be produced by employing diazotized 4-amino-2-cyano-21-chlorostilbene, or 4-amino-2-cyano-41-chlorostilbene, or 4-amino-2-cyano-41-methylstilbene.  Example 9 relates to the production of dyestuffs by coupling 5-amino-acenaphthene with diazotized 4-amino-2-cyano-21 methoxystilbene (or 41-methoxystilbene), or 4-amino-2-cyano-31, 41-dioxymethylene stilbene.  Example 13 describes the treatment, for 30 minutes, of pale-yellowish glycol/terephthalic acid condensation material in a bath comprising liquor which contains 2-[211-cyano-stilbyl-411]-(naphtho-11, 21 : 4, 5)-1, 2, 3-triazole <FORM:0863164/IV(c)/1> The liquor is produced by dissolving the brightening agent in dimethyl formamide, mixing this solution with a small quanity of dilute aqueous dodecyl alcohol polyglycol ether, and then diluting with water until the concentration of the brightening agent is 0,005g./litre.  Material so treated has a whiter appearance in daylight than untreated material.  Specification 774,010 is referred to.ALSO:Triazolyl-cyano-stilbene compounds having the structure <FORM:0863164/III/1> wherein A and B are aromatic nuclei and n is either 0 or 1 with the proviso that A must contain a cyano substituent when n = 0 (see Group IV (b)), are suitable for use as brightening agents for fats and waxes.  Specification 774,010 is referred to.