Synthesis of Some Coumarin Derivatives as Potential Laser Dyes

Abstract

With a view to extend the tunability range and maximum output of the coumarin series of dyes, 15 new 3-substituted 7-hydroxycoumarins emitting in the blue-green region of the visible spectrum are synthesized, some of which show laser activity.

Synthesis of Novel Carboxylated Benzoxazolylcoumarins.

“…A second method was used in which the suitable 2-cyanomethylbenzoxazole was prepared first and then reacted with the corresponding ortho-hydroxybenzaldehyde (Scheme 2). 5,11 The yield for compound 2a improved by this method. Attempts to purify compound 3b further led to decomposition mainly to the 7-N,N-diethylcoumarin-3-carboxylic acid possibly due to hydrolysis of the oxazole ring.…”

BF3·Et2O Catalysed 4-Aryl-3-phenyl-benzopyrones, Pro-SERMs, and Their Characterization

“…Among the coumarin derivatives more attention is given to 4-substituted coumarins, but there are very few methods known for synthesis. Route 1 ( Scheme 1 ) to coumarins incorporates Pechmann [ 59 , 60 ], Knoevenagel [ 61 – 64 ], Reformatsky [ 61 – 64 ], Perkin [ 65 ], and Wittig [ 66 ] condensation reactions. To make these reactions efficacious, several variations in terms of catalyst and reaction conditions have been done.…”

A Synthetic Route to 3‐(Heteroaryl)‐7‐hydroxycoumarins Designed for Biosensing Applications

“…In this paper, we report the practical implementation of this new synthetic strategy for the preparation of original water‐soluble and/or bioconjugatable derivatives of 3‐(2‐benzimidazolyl)‐7‐hydroxycoumarin 13–15. A further extension of this method to the direct synthesis of the unknown 3‐(2‐benzoselenazolyl)‐7‐hydroxycoumarin was also explored.…”