CH476744A - Process for the preparation of substituted 2- (2'-hydroxyphenyl) benzotriazole compounds - Google Patents

Description

  

  Process for the preparation of substituted 2- (2'-hydroxyphenyl) benzotriazole compounds It has been found that valuable light stabilizers are obtained if a 2-amino-2'-hydroxy-1,1'-azobenzene compound of the formula I is used
EMI0001.0002
    in the X the groups
EMI0001.0004
    and is in position 4, 5 or 4 ', where R is an acyl radical or cyclic carbonimide radical free of color-generating groups and R is hydrogen, cycloalkyl or an aliphatic or araliphatic radical free of color-generating groups, and Y is -CO-, -CS- and -S02- and 2 -R2-, R3-O-, where R2, Ra and R4 are aliphatic
EMI0001.0007
   Leftovers are

    D denotes -CO- or a methylene group optionally substituted by alkyl groups, and in formula I the nucleus A in positions 4, 5 and 6 by alkyl, alkoxy groups or halogen atoms, and, if X is not in the nucleus A, also by carboxyl -, Carboxylic acid ester, carboxylic acid amide, sulfonic acid amide or alkylsulfonyl groups, and the nucleus Bin in the positions 3 ', 4' and 5 'can be substituted by hydrocarbon groups, alkoxy groups or halogen atoms, with ring closure to form a compound of the formula II oxidized
EMI0001.0014
    wherein X is in position 4 or 4 '.



  The benzene ring A can, as mentioned, in the positions 4, 5 and 6 by alkyl groups such as methyl, ethyl, isobutyl groups, alkoxy groups such as methoxy and butoxy groups, halogens such as chlorine and bromine, and, if X is not in the nucleus A, also through carboxyl groups, carboxylic acid ester groups, namely carboxylic acid alkyl ester groups, such as carbomethoxy, carboethoxy, carbopropoxy or carbobutoxy groups, optionally carboxylic acid amide groups with aliphatic, cycloaliphatic or araliphatic substitution on the nitrogen, or sulfonic acid amide groups,

   such as carboxylic acid or sulfonic acid amide, methyl amide, ethyl amide, cyclohexyl amide, benzyl amide, dimethyl amide, diethyl amide, N-methyl-N-cyclohexyl amide, γ-methoxypropyl contain amide, piperidide or morpholide groups, and also alkyl sulfonyl groups, such as methylsulfonyl or ethylsulfonyl groups.



  The benzene ring B in the 3 ', 4' and 5 'positions can also be replaced by hydrocarbon groups, such as methyl, ethyl, benzyl, α-phenylethyl, cyclohexyl or phenyl groups, alkoxy groups such as methoxy, ethoxy -, propoxy, isopropoxy or n-butoxy groups or Ha logene, such as chlorine or bromine, may be substituted.



  Benztriazole compounds which absorb particularly long wavelengths are obtained when acidifying substituents are introduced in the 4- or 5-position, and basic substituents in the 3 'and / or 5' position. Benztriazole compounds with a particularly high molar extinction in the range of 330-350 mg are obtained when basic substituents are in the 4'- and / or 5-position. The molar absorption in the range of 300 mg is promoted by optionally further substituted alkyl substituents.



  Examples of basic substituents are alkoxy groups, such as the methoxy, isopropoxy, cyclohexyloxy and benzyloxy groups; Examples of acidifying substituents are alkylsulfonyl groups, such as the methyl and ethylsulfonyl groups, sulfonic acid amide groups, such as the sulfonic acid methyl, -butyl and -cyclohexylamide groups, and the carboxyl group and its esters or amides.



  The radical of an organic acid denoted by R and free of color-generating groups is embodied, for example, by a carboxylic acid radical of the formula R2-CO-, a carbonic acid monoester radical of the formula R3-OCO-, a carbamoyl or thiocarbamoyl radical of the formula
EMI0002.0020
   respectively
EMI0002.0021
    a sulfonic acid radical of the formula R3-SO2- and a cyclic carbonic acid imide radical of the formula
EMI0002.0022
    wherein A complements a 5- or 6-membered ring of aromatic character, preferably a 1,3,5-triazinyl (2) radical of the formula
EMI0002.0025
    In these acyl radicals, R2, R3, R4, R, and R "are each, independently of one another, an organic radical, for example an aliphatic, cycloaliphatic,

    araliphatic or aromatic radical, R2 and R4 also hydrogen and R, and Re also an alkoxy, cycloalkoxy, aralkoxy or aryloxy, alkylthio, cycloalkylthio, aralkylthio or arylthio radical or an optionally aliphatic, cycloaliphatic , araliphatically or aromatically substituted amino radical.

    The radical R2-CO- can be derived from an optionally substituted, aliphatic saturated monobasic carboxylic acid, for example formic acid, acetic acid, propionic acid, butyric acid, pentane carboxylic acid, heptane carboxylic acid, nonane carboxylic acid, undecanoic acid, tridecanoic acid, pentadecanoic acid, chloroacetic acid, or chloroacetic acid, or a- or ss-chloro- or a- or ss-bromopropionic acid, methoxy- or ethoxyacetic acid,

   Methyl or ethylmercaptobutyric acid or optionally N-substituted amino acetic acids or β-aminopropionic acids, from an aliphatic saturated polybasic optionally substituted carboxylic acid, in particular from a monoester of such an acid, for example from oxalic acid monomethyl or monoethyl ester or succinic acid monomethyl or monoethyl ester; of an aliphatic unsaturated monocarboxylic optionally substituted carboxylic acid, for example acrylic or methacrylic acid;

   of an aliphatic, unsaturated, polybasic, optionally substituted carboxylic acid, in particular of a monoester of an acid such as maleic acid or fumaric acid monomethyl or monoethyl ester; from a cycloaliphatic carboxylic acid, for example cyclohexanecarboxylic acid; may be derived from an araliphatic carboxylic acid such as phenylacetic acid, dihydrocinnamic acid, α-phenylacrylic acid or cinnamic acid or from an aromatic carboxylic acid such as benzoic acid, p-toluic acid or phthalic acid monoalkyl ester.



  Compounds according to the invention contain, for example, N-methyl, N-ethyl, N-propyl, N-butyl, N-cyclohexyl, N-benzyl, N-phenyl, N, N as carbamoyl or thiocarbamoyl radicals -Dimethyl-, N, N-diethyl-, N, N-dipropyl-, N, N-dibutyl-, N, N-dicyclohexyl-, N, N-dibenzyl-, N-methyl-N-ethyl- or N-methyl-N-phenylcarbamoyl or thiocarbamoyl groups.



  The R3SO2- radical is derived in particular from aromatic sulfonic acids, for example from benzene or p-toluenesulfonic acid.



  Examples of residues of the formula
EMI0002.0059
    are the 4,6-bis-methylamino-, 4,6-bis-äthylamino-, 4,6-bis-propylamino-, 4,6-bis-butylamino-, 4,6-bis-dimetyi- amino, 4 , 6-bis-diethylamino-, 4,6-bis-dipropylamino- or 4,6-bis-dibutylamino-, 4-amino-6-N, N-dimethylamino-, 4-amino-6-N-methyl -N-ethylamino-, 4-amino- 6-N-methyl-N-propylamino-, 4-amino-6-N-methyl-N-butylamino-, 4-amino-6-N-methyl-N-hexylamino- ,

       4-amino-6-N-methyl-N-octylamino-, 4,6-bis-methylmerkapto, 4-methylmercapto-6-dodecylmercapto, 4-methoxy-6-methylamino- or 4-ethoxy -6-ethylamino-1,3,5-triazinyl- (2) radical.



  If R1 is a cycloalkyl radical or an aliphatic or araliphatic radical free of color-generating groups, it means, for example, the methyl or ethyl group, the cyclohexyl group or the benzyl group. If R1 and the acyl radical form a ring together with the nitrogen, it is, for example, a lactam ring, for example the caprolactam ring, or a cyclic imide radical, for example the succinimide radical.



  The oxidation of the compound of formula 1 to the triazole compound is carried out by methods known per se, for example with Cu (II) salts in an alkaline medium.



  The new substituted 2- (2'-hydroxyphenyl) benzotriazole compounds of the formula II are, depending on the substitution, colorless to slightly yellow in color and absorb UV light. Compared to previously known Ver compounds of a similar constitution, they show an improved absorption of UV light. They are therefore particularly suitable in all cases where the lowest possible UV transparency is desired.



  The 5-acylamido compounds are particularly favorable with regard to lightfastness. In general, the lightfastness increases both in the case of the 5-acylamido and the 4'-acylamido compounds in the following order: triazinylamino> carboxamido · sulfonic acid amido compounds; d. In other words, the more acidic the free acid corresponding to the acyl radical, the better the lightfastness.



  The new UV absorbers are incorporated into the light-sensitive carriers in small amounts of 0.001-5 percent, in particular in amounts of 0.01-1 percent of the carrier material. Polymers are primarily suitable as carrier materials for the new compounds of the formula II.



  The photosensitive materials can also be protected from the harmful effects of light by coating them with a protective layer containing at least one compound of the formula II according to the definition, for example a varnish, or by coating them with such light stabilizers - expediently film-like - structures. In both of these cases, the amount of light stabilizers added is advantageously 10-30 percent (based on the protective layer material) for protective layers less than 0.01 mm thick and 1-10 percent for protective layers 0.01-0.1 mm thick. In general, the more colorless the benzotriazole compounds are, the more valuable they are, otherwise they can easily cause the end product to turn yellow.



  In the following example, unless otherwise noted, the parts mean parts by weight. The temperatures are given in degrees Celsius. Parts by weight have the same relationship to parts by volume as kilograms are to liters. <I> Example </I> 2.76 parts of 2,4-diamino-5-methyl-2'-hydroxy-5'-chloro-1,1'-azobenzene are mixed with 1.02 parts of acetic anhydride in 10 parts by volume of glacial acetic acid and converted into the 2-amino-4-acetylamido-5-methyl-2'-hydroxy-5'-chloro-1,1'-azobenzene by heating to reflux.

    The product is precipitated by pouring the reaction mixture onto water, filtered off with suction and refluxed for one hour while still moist in a boiling solution of 5.04 parts of copper sulfate pentahydrate, 6 parts by volume of water, 8 parts by volume of 20 percent ammonia solution and 40 parts by volume of 50 percent alcohol . To remove the copper, the mixture is mixed with 1.5 parts of sodium sulfide and, after stirring for two hours, filtered off to remove the copper sulfide. The filter residue is extracted with 20 parts by volume of hot ethylene glycol monomethyl ether and the copper sulphide is filtered off while hot.

   The 2- (2 'hydroxy-5'-chlorophenyl) -4-methyl-5-acetylamido-benzotriazole is obtained by evaporating the combined filtrates in vacuo. F. 260 (from glacial acetic acid).



  The 2,4-diamino-5-methyl-2'-hydroxy-5'-chloro-1,1'-azobenzene used as the starting material is prepared as follows: 61 parts of 2,6-diaminotoluene are 50 parts by volume of glacial acetic acid Dissolved parts by volume of concentrated hydrochloric acid and 72 parts of 4-chloro-2-aminophenol diazotized in the usual way were added dropwise at 0-5 within two and a half hours. After stirring overnight at 0-5, the acid is blunted to pH 4-4.5 with sodium hydroxide solution, the dye precipitating out. It is filtered off, washed with water and dried in vacuo.

 

Claims (1)

PATENT CLAIM Process for the preparation of substituted 2- (2'-hydroxyphenyl) -benzotriazole compounds, characterized in that a 2-amino-2'-hydroxy-1,1'-azobenzene compound of the formula I EMI0003.0040 in the X the groups EMI0003.0041 and is in position 4, 5 or 4 ', in which R is an acyl radical or cyclic carbonimide radical free of color-generating groups and R is hydrogen, Cycloalkyl or an aliphatic or araliphatic radical free of color-generating groups, and Y denotes -CO-, -CS- and -S02- and Z -R2-, Rg-O-, EMI0003.0050 wherein R2, R3 and R4 are aliphatic radicals, D is -CO- or a methylene group optionally substituted by alkyl groups, and in formula 1 the nucleus A in positions 4, 5 and 6 by alkyl, alkoxy groups or halogen atoms, and, if X is not in the core A, also by carboxyl, carboxylic acid ester, Carboxylic acid amide, sulfonic acid amide or alkylsulfonyl groups, and the nucleus B in positions 3 ', 4' and 5 'can be substituted by hydrocarbon groups, alkoxy groups or halogen atoms, oxidized with ring closure to form a compound of the formula II EMI0004.0006 wherein X is in position 4 or 4 '.