Benzofurane benzoxazoles

Abstract

Compounds of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 denote hydrogen, alkyl, alkoxy or halogen,A denotes aryl or a radical of the formula ##STR2## wherein R.sup.8 denotes aryl, alkyl, aralkyl, styryl or alkoxy,R.sup.9 denotes hydrogen, CN, COOR, CONRR' or R.sup.8 and X denotes N or C(R.sup.10),R.sup.4 and R.sup.10 denote hydrogen, alkyl or aryl,R.sup.5, R.sup.6 and R.sup.7 denote hydrogen, halogen or alkyl, inter alia,R denotes alkyl andR' denotes R or H,are valuable optical brighteners for polyesters, polyamides, cellulose esters and polyacrylonitrile.

Description

The invention relates to compounds of the formula ##STR3## in which R.sup.1, R.sup.2 and R.sup.3 denote hydrogen, alkyl, alkoxy or halogen,

A denotes aryl or a substituent of the general formula ##STR4## in which R.sup.8 denotes aryl, alkyl, aralkyl, styryl or alkoxy, and R.sup.9 denotes hydrogen, CN, COOR, CONRR' or R.sup.8, or R.sup.8 and R.sup.9 together denote a fused-on hydroaromatic or aromatic ring, and X denotes N or C(R.sup.10), R.sup.10 denotes hydrogen, alkyl or aryl, R.sup.4 denotes hydrogen, aryl or alkyl, R.sup.5 denotes hydrogen, halogen or alkyl, R.sup.6 denotes hydrogen, halogen, alkyl, alkoxy, alkylsulphonyl, phenylsulphonyl, CN, CF.sub.3, COOR, SO.sub.3 R, CONRR' or SO.sub.2 NRR', R.sup.7 denotes hydrogen, halogen, alkyl or alkoxy, R denotes alkyl and R' denotes R or H, and wherein the abovementioned hydrocarbon radicals and alkoxy radicals and the optionally fused-on ring systems can be substituted by substituents customary in brightener chemistry.

Suitable alkyl and alkoxy radicals in any context have 1 to 4 C atoms, and methyl, ethyl, methoxy and ethoxy are preferred.

Suitable aryl radicals are phenyl radicals which are optionally substituted by alkyl, alkoxy, halogen, CN, COOR and SO.sub.2 R, inter alia. "Halogen" is understood, above all, as bromine and, in particular, chlorine.

Suitable aralkyl radicals are phenylalkyl radicals which are optionally substituted by alkyl, alkoxy, halogen, CN, COOR and SO.sub.2 R, inter alia.

Suitable fused-on rings are optionally substituted cyclohexane, benzene or naphthalene rings.

Compounds of the formula (I)

wherein R.sup.1, R.sup.2 and R.sup.3 denote hydrogen, methyl, ethyl, methoxy or chlorine, A denotes phenyl which is substituted by C.sub.1 -C.sub.4 -alkyl and/or C.sub.1 -C.sub.4 -alkoxy, or a substituent of the general formula ##STR5## in which R.sup.8 denotes C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, a phenyl radical which is optionally substituted by C.sub.1 -C.sub.4 -alkyl, phenyl, C.sub.1 -C.sub.4 -alkoxy or chlorine, benzyl or styryl and R.sup.9 denotes hydrogen, cyano, carboxyl, C.sub.1 -C.sub.4 -alkyl-carbonylamino, benzoylamino or R.sup.8, or R.sup.8 and R.sup.9 together denote a fused-on naphthalene or benzene ring, which can optionally be substituted by C.sub.1 -C.sub.4 -alkyl and/or C.sub.1 -C.sub.4 -alkoxy, and X denotes N or C(R.sup.10), R.sup.10 denotes hydrogen, C.sub.1 -C.sub.4 -alkyl or phenyl, R.sup.4 denotes hydrogen, alkyl with 1 to 4 C atoms, preferably methyl, or phenyl which is optionally substituted by methyl and/or methoxy, R.sup.5 denotes hydrogen, chlorine or C.sub.1 -C.sub.4 -alkyl, R.sup.6 denotes hydrogen, alkyl with 1 to 4 C atoms, preferably methyl, methoxy, chlorine, alkylsulphonyl with 1 to 4 C atoms, cyano, COOH, SO.sub.3 H, COOR.sup.11, SO.sub.3 R.sup.11 or CON(R.sup.4).sub.2, R.sup.7 denotes hydrogen, C.sub.1 -C.sub.4 -alkyl, methoxy or chlorine and R.sup.11 denotes C.sub.1 -C.sub.4 -alkyl, preferably methyl, C.sub.2 -C.sub.4 -hydroxyalkyl, cyanoethyl, phenyl which is optionally substituted by chlorine, methyl or methoxy, cyclohexyl or benzyl, are of particular importance from an industrial point of view.

The compounds of the formula (I) can be prepared by various methods. One variant is characterised in that compounds of the formula ##STR6## in which R.sup.12 denotes alkoxy, chlorine or bromine, are reacted with compounds of the formula ##STR7## in a manner which is known per se (compare DE-OS (German Published Specification) 2,162,439).

The compounds of the formula (I) can furthermore be prepared by a process in which compounds of the formula ##STR8## or salts thereof, are first reacted with compounds of the formula ##STR9## in which Hal denotes chlorine or bromine,

to give products of the formula ##STR10## and these are then cyclised to give compounds of the formula (I).

Compounds of the formula (I) can also be prepared by reacting a compound of the formula ##STR11## with a compound of the formula ##STR12##

Compounds of the formula (I) in which R.sup.4 denotes H can also be formed by condensation of compounds of the formula (VII) with compounds of the formula ##STR13## to give the intermediate products of the formula ##STR14## and subsequent rearrangement of these compounds.

The new compounds are suitable as optical brighteners for natural and synthetic fibres, in particular polyesters, polyamides, cellulose esters and polyacrylonitrile. They are also suitable for bulk brightening of these substrates.

EXAMPLE 1

5.9 g of 2-aminophenol are dissolved in 120 ml of pyridine, and 20 g of 2-(4-chlorocarbonyl-phenyl)-6-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-benzofurane are added in small portions in the course of 15 minutes. The reaction mixture is warmed to 80.degree. C. for 8 hours. It is then cooled to room temperature and poured onto 1,000 ml of 10% strength hydrochloric acid and the solid is filtered off, washed until the runnings are neutral and dried. The intermediate product of the formula ##STR15## is heated in a mixture of 140 ml of trichlorobenzene and 0.2 g of boric acid to 200.degree. C. for 4 hours and the water formed is distilled off. The mixture is then stirred until cold and the solid is filtered off, washed with methanol and dried at 100.degree. C. After recrystallisation from glycol monomethyl ether/active charcoal, 13.5 g (60% of theory) of the compound of the formula ##STR16## which exhibits blue fluorescence when dissolved in dimethylformamide, are obtained.

2-(4-Chlorocarbonyl-phenyl)-6-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-benzofurane is prepared as follows:

100 g of 4-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-salicylaldehyde, 47 g of 4-cyanobenzyl chloride and 62.2 g of potassium carbonate are heated in 700 ml of dimethylsulphoxide to 80.degree. C. for 8 hours. The reaction mixture is then poured onto 3,000 ml of water and rendered acid to Congo Red with concentrated hydrochloric acid and the solid is filtered off and washed until the runnings are neutral. The still moist intermediate product is dissolved in 1,300 ml of dimethylformamide at 80.degree. C., 76 g of potassium hydroxide powder (88% pure) are added at 30.degree. C. and the mixture is stirred at 30.degree. C. for 5 hours. It is poured onto 5,000 ml of water and rendered acid to Congo Red with concentrated HCl and the solid is filtered off, washed until the runnings are neutral and dried at 100.degree. C. The crude product is refluxed in 1,200 ml of glycol monomethyl ether and 730 ml of 50% strength potassium hydroxide solution for 13 hours. The reaction mixture is poured onto a mixture of 970 ml of concentrated hydrochloric acid and 1,940 g of ice and the precipitate is filtered off, washed until the runnings are neutral and dried at 100.degree. C. Yield: 95 g (80.2% of theory) of 2-(4-carboxy-phenyl)-6-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-benzofurane of melting point 275.degree. C. The carboxylic acid is stirred in 940 ml of distilled toluene, 117.5 g of thionyl chloride and 5 ml of dimethylformamide are added and the mixture is heated gradually to the boiling point. It is refluxed for 1 hour and clarified with active charcoal, the filtrate is cooled and the solid is filtered off and dried in vacuo at 80.degree. C.

Yield: 71.6 g (72% of theory) of 2-(4-chlorocarbonylphenyl)-6-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-benzofurane of melting point 201.degree. C.

EXAMPLE 2

The compound of the formula (101) can also be prepared in the following manner:

9.2 g of the sodium salt of 4-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-salicylaldehyde (98.2% pure) and 7.3 g of 2-(4-chloromethyl-phenyl)-benzoxazole are stirred in 250 ml of dimethylformamide at 70.degree. C. for 8 hours. 14.2 g of potassium tert.-butylate (95% pure) are then added at room temperature and the mixture is stirred at 60.degree. C. for 4 hours. After pouring the mixture onto 500 ml of water, the solid is filtered off, washed until the runnings are neutral and dried at 100.degree. C. When recrystallised from glycol monomethyl ether/active charcoal, 12.2 g (86.9% of theory) of a compound which is identical to the compound of the formula (101) and exhibits blue fluorescence in solution in dimethylformamide are obtained.

EXAMPLE 3

If the 2-(4-chloromethyl-phenyl)-benzoxazole is replaced by the correspondingly substituted analogues and the procedure is otherwise as described in Example 2, the following compounds of the formula ##STR17## are obtained.

______________________________________ Colour of fluorescence inNo. X.sup.1 X.sup.2 X.sup.3 solution in dimethylformamide______________________________________301 CH.sub.3 H H blue302 CH.sub.3 H CH.sub.3 blue303 CH.sub.3 CH.sub.3 H blue304 C(CH.sub.3).sub.3 H H blue305 Cl H H blue-green306 CO.sub.2 CH.sub.3 H H blue-green______________________________________

EXAMPLE 4

If the sodium salt of 4-(4-methyl-5-phenyl-1,2,3-triazol-2-yl)-salicylaldehyde is replaced by the sodium salt of 4-(4-ethyl-5-methyl-1,2,3-triazol-2-yl)-salicylaldehyde, the compounds of the formula ##STR18## are obtained analogously to Example 2:

______________________________________ Colour of fluorescence inNo. X.sup.1 X.sup.2 X.sup.3 solution in dimethylformamide______________________________________401 H H H blue-violet402 CH.sub.3 H H blue403 CH.sub.3 H CH.sub.3 blue404 CH.sub.3 CH.sub.3 H blue405 C(CH.sub.3).sub.3 H H blue406 Cl H H blue-green407 CO.sub.2 CH.sub.3 H H blue-green______________________________________

EXAMPLE 5

Using the sodium salt of 4-(naphth[1,2-d]-1,2,3-triazol-2-yl)-salicylaldehyde, the compounds of the formula ##STR19## are obtained analogously to Example 2:

______________________________________ Colour of fluorescence inNo. X.sup.1 X.sup.2 X.sup.3 solution in dimethylformamide______________________________________501 H H H blue502 CH.sub.3 H H blue-green503 CH.sub.3 H CH.sub.3 blue-green504 CH.sub.3 CH.sub.3 H blue-green505 C(CH.sub.3).sub.3 H H blue-green506 Cl H H blue-green507 CO.sub.2 CH.sub.3 H H blue-green______________________________________

EXAMPLE 6

Using the sodium salt of 4-phenyl-salicylaldehyde or of 2-hydroxy-4-phenyl-acetophenone, the compounds of the formula ##STR20## are obtained analogously to Example 2:

______________________________________ Colour of fluorescence in solution inNo. X.sup.1 X.sup.2 X.sup.3 X.sup.4 dimethylformamide______________________________________601 H H H H violet602 H CH.sub.3 H H blue-violet603 H CH.sub.3 H CH.sub.3 blue604 H CH.sub.3 CH.sub.3 H blue605 H C(CH.sub.3).sub.3 H H blue-violet606 H Cl H H blue607 H CO.sub.2 CH.sub.3 H H blue-green608 CH.sub.3 H H H violet609 CH.sub.3 CH.sub.3 H H blue-violet610 CH.sub.3 CH.sub.3 H CH.sub.3 blue611 CH.sub.3 CH.sub.3 CH.sub.3 H blue612 CH.sub.3 C(CH.sub.3).sub.3 H H blue-violet613 CH.sub.3 Cl H H blue-violet614 CH.sub.3 CO.sub.2 CH.sub.3 H H blue______________________________________

Claims

1. A benzofurane compound of the formula ##STR21## in which R.sup.1, R.sup.2 and R.sup.3 denote hydrogen, alkyl, alkoxy or halogen,

R.sup.4 denotes hydrogen, aryl or alkyl,

R.sup.5 denotes hydrogen, halogen, or alkyl,

R.sup.6 denotes hydrogen, halogen, alkyl, alkoxy, alkylsulphonyl, phenylsulphonyl, CN, CF.sub.3, COOR, SO.sub.3 R, CONRR' or SO.sub.2 NRR',

R.sup.7 denotes hydrogen, halogen, alkyl or alkoxy,

R denotes alkyl and

R' denotes alkyl or H,

R.sup.8 denotes aryl, alkyl, aralkyl, styryl or alkoxy, and

R.sup.9 denotes hydrogen, CN, COOR, CONRR' or R.sup.8, or R.sup.8 and R.sup.9 together denote a fused-on hydroaromatic or aromatic ring, and

the abovementioned hydrocarbon radicals and alkoxy radicals and the optionally fused-on ring systems optionally being substituted by substituents customary in brightener chemistry.

2. A benzofurane compound according to claim 1, of the formula ##STR22##