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Chapter – 4 Studies on different types of reactions…..
4.3 INTRODUCTION TO COUMARIN
Coumarin is a chemical compound (2H-chromen-2-one, 1-benzopyran-
2-one, benzopyrone; C9H6O2); a toxin found in many plants, notably in high
concentration in the tonka bean, vanilla grass, woodruff, mullein, and bison
grass. It has a sweet scent, readily recognised as the scent of newly-mown
hay, and has been used in perfumes since 1882. It has clinical medical value
as the precursor for several anticoagulants, notably warfarin, and is used as a
gain medium in some dye lasers.
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O 2 O
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The isolation of coumarin was first reported by Vogel 130 in 1820. He
isolated coumarin from tonka beans, bearing the characteristic aroma of
cutted grass. The name of coumarin originates 131 from a Caribbean word
“coumarou” for the tonka tree, which was known botanically at one time as
Coumarouna odorta Aubl, coumarin is now the accepted trival name.
Coumarin was first synthesized in 1868 on treatment of sodium salt of ohyroxy
benzaldehyde with acetic anhydride. 132a, 132b Compounds containing
coumarin subunit possess a wide range of activities and show an interesting
reactivity. 133-136 This is consequence of the rich electronic structure of
coumarin which offers abundant possibilities for diversified activity and
reactivity of the system.
4.3.1 SYNTHESIS OF 4-HYDROXY COUMARIN
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Perkin 132 synthesized coumarin and then several methods are
reported for the synthesis of 4-hydroxy coumarins and their 4-hydroxy
substituted derivatives namely:
Department of Chemistry, Saurashtra University, Rajkot – 360 005 199
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Fig. 4.9
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