Heterocycles as Structural Units in New Optical Brighteners

Abstract

Dedicated to Professor Siegjiried Petersen on the occasion of his 65th birthdayOptical brighteners are used in detergents, textiles, paper, plastics, and paints. Most optical brighteners contain heterocycles such as coumarins, 2-pyrazolines, naphthalimides, pyrazoles, triazoles, oxadiazoles, and triazines. In this article the syntheses, properties, and applications of new optical brighteners are described with references to patent literature.

Facile iron(III) chloride hexahydrate catalyzed synthesis of coumarins

“…[5][6][7][8][9][10][11][12] Apart from their pharmaceutical applications, [13][14] coumarins have been used as additives in foods, perfumes and cosmetics as well as in the preparation of optical brighteners, laser dyes, fluorescent labels and nonlinear optical chromophores. [15][16][17][18][19] The Pechmann reaction 20 is known as one of the most valuable methods for the synthesis of coumarins since it proceeds from simple starting materials, a phenol and a -keto ester, together with an acid catalyst. Various protocols have been developed by using different catalysts including sulfuric acid, 20 trifluoroacetic acid, 21 phosphorus pentaoxide, 22 aluminium chloride, [23][24] indium(III) chloride, 25 titanium(IV) chloride, 26 silica gel supported zirconyl chloride octahydrate, 27 samarium(III) nitrate hexahydrate, 28 bismuth(III) nitrate pentahydrate, 29 ionic liquids 30 and many more.…”

An efficient methodology for the synthesis of 3-styryl coumarins

“…5 Depending on the nature and substitution pattern, coumarins show exceptional optical properties, 6 as they constitute the largest class of fluorescent dyes, 7 widely used as emission layers in organic light-emitting diodes (OLED), 8 optical brighteners, 9 nonlinear optical chromophores, 10 fluorescent whiteners, 11 fluorescent labels and probes for physiological measurement 12 and more recently, in labelling 13 and caging. 14 Developments from the last decade show that the introduction of appropriated substituents into the coumarin ring contribute to structures with improved photophysical and spectroscopic proprieties.…”

Synthesis and Photophysical Characterizations of Thermal -Stable Naphthalene Benzimidazoles

“…1,8-Naphthalimides are generally fluorescent compounds for which a series of biological (local anesthetics [4], DNA cleaving agents [5], tumoricidals [6] and non-biological optical brighteners [7], lucifer dyes [8]) applications have been found. 1,8-Naphthalimide and bisnaphthalimide derivatives are promising anticancer agents [9,10], the sulfonated derivatives are good antiviral agents with selective in vitro activity against the human immunity deficiency virus, HIV-1 [11].…”