Claims
- 1. A process for the preparation of a fluorescent brightener consisting of (a) 51 to 99% of an unsymmetrically substituted compound of the formula ##STR55## in which R and R.sub.1 are identical or different and, if R and R.sub.1 are identical, the substituent positions of R and R.sub.1 must be different, and in which R and R.sub.1 independently of one another are CN or a carboxylic acid ester group and (b) 49 to 1% of a symmetrically substituted compound of the formula ##STR56## in which R is as defined above and the two Rs are bonded to identical positions of their phenyl rings, which comprises reacting terephthalaldehyde with a compound of the formula ##STR57## to give a mixture of the compounds of the formulae ##STR58## and then further reacting this mixture with a compound of the formula ##STR59## to yield the fluorescent brightener wherein X and Y are identical or different and independently of one another are (a) hydrogen, (b) a radical of the formula --COOZ in which Z is alkyl or (c) a radical of the formula --ZnBr, --ZnCl, --MgBr, --MgCl, ##STR60##
- 2. A process according to claim 1 wherein X and Y independently of one another are a group of the formula ##STR61##
- 3. A process according to claim 2 wherein terephthalaldehyde is reacted with a compound of the formula ##STR62## to give a mixture of the compounds of the formula ##STR63## and of the formula ##STR64## or to give a mixture of the compounds of the formula ##STR65## and of the formula ##STR66## and then reacting the particular mixture obtained with a compound of the formula ##STR67## to give a fluorescent brightener consisting of 51-99% of the compound of the formula ##STR68## and 49-1% of the compound of the formula ##STR69## or consisting of 51-99% of the compound of the formula ##STR70## and 49-1% of the compound of the formula ##STR71##
- 4. A process according to claim 1 wherein the reaction of terephthalaldehyde with a compound of the formula ##STR72## is carried out in a solvent or solvent mixture in which the resulting monoaldehyde is sparingly soluble and crystallizes out.
- 5. A process according to claim 2 wherein the reaction of terephthalaldehyde with a compound of the formula ##STR73## is carried out in the presence of an alkaline condensing agent, at temperatures between 0.degree. and 50.degree. C.
- 6. A process according to claim 1, wherein the monoaldehyde-containing mixture obtained in the first stage is isolated and then further reacted, in a solvent in which the particular monoaldehyde is soluble.
- 7. A process according to claim 6 wherein the reaction of the mixture obtained in the first stage with a compound of the formula ##STR74## is carried out in the presence of an alkaline condensing agent at temperatures between 20.degree. and 100.degree. C.
- 8. The process of claim 2 wherein X and Y are ##STR75##
- 9. A process for the preparation of an unsymmetrically substituted optical brightener compound of the general formula ##STR76## where R and R.sub.1 independently of one another are cyano, or C.sub.1-6 alkoxycarbonyl, and free of p,p'-substituted compounds, which comprises reacting in a first step terephthaladehyde with a phosphonate compound of the general formula IIa ##STR77## or of the general formula IIb ##STR78## where R and R.sub.1 have the above meanings in the presence of an alkali, in a solvent from which the monocondensation product of terephthaldehyde and the phosphonate compound precipitates to form a first reaction product containing the monocondensation product and thereafter completing the reaction to prepare a compound of formula (I) by reacting the first reaction product in the presence of alkali and an inert solvent with a different phosphonate compound of formula IIa or IIb, with the proviso that at least one compound of formula IIa and a compound of formula IIb are reacted successively in the process.
- 10. A process as claimed in claim 9, wherein a compound in which R and R.sub.1 are cyano is prepared.
- 11. The process as claimed in claim 9 wherein X and Y are cyano and the phosphonate compound employed in the first step is of formula IIb.
- 12. The process of claim 11 wherein more than one but less than two equivalents of a compound of formula IIb per mol of terephthaldehyde is employed in the first step.
- 13. The process of claim 9 wherein the alkyl group in formulae IIa and IIb is C.sub.1 -C.sub.4 alkyl.
- 14. A process according to claim 9 wherein the solvent employed to form the first reaction product is one in which the said first reaction product has low solubility and from which the said first reaction product precipitates out.
- 15. A process for the preparation of a fluorescent brightener consisting of 51 to 99% of an unsymmetrically substituted compound of the formula ##STR79## in which R and R.sub.1 are identical or different, and, if R and R.sub.1 are identical the substituent positions of R and R.sub.1 must be different, and in which R and R.sub.1 independently of one another are CN or a carboxylic acid ester group, and 49-1% of a symmetrically substituted compound of the formula ##STR80## in which R is as defined above and the two R's are bonded to identical positions of their respective phenyl rings, which comprises, in a first stage, reacting terephthalaldehyde with a compound of the formula ##STR81## in the presence of dimethylformamide as solvent to give a mixture of the compounds of the formulae ##STR82## and then reacting said monoaldehyde-containing mixture obtained in the first stage without isolation with a compound of the formula ##STR83## wherein X and Y are identical or different and independently of one another are hydrogen or a radical of the formula --COOZ, in which Z is alkyl; or are radicals of the formulae --ZnBr, --ZnCl, --MgBr, --MgCl, ##STR84##
Priority Claims (2)
Number |
Date |
Country |
Kind |
11040/79 |
Dec 1979 |
CHX |
|
3058/80 |
Apr 1980 |
CHX |
|
Parent Case Info
This application is a continuation of application Ser. No. 213,150, filed Dec. 4, 1980, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (13)
Number |
Date |
Country |
0023027 |
Jan 1981 |
EPX |
0032254 |
Jul 1981 |
EPX |
2647179 |
May 1977 |
DEX |
366512 |
Feb 1963 |
CHX |
382709 |
Dec 1964 |
CHX |
388929 |
Jun 1965 |
CHX |
388294 |
Jun 1965 |
CHX |
389585 |
Jun 1965 |
CHX |
411329 |
Nov 1966 |
CHX |
416078 |
Jan 1967 |
CHX |
920988 |
Mar 1963 |
GBX |
929436 |
Jun 1963 |
GBX |
1045443 |
Oct 1966 |
GBX |
Non-Patent Literature Citations (4)
Entry |
Castells et al, Chemical Abstracts 91 (1979), 91300r. |
Porshnev et al, C.A. 90 (1979), 72006n. |
Schiemenz et al., C.A. 65 (1966), 15417a. |
465,548 1/1969, Switzerland. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
213150 |
Dec 1980 |
|