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Chapter – 5 Synthesis and Characterization…..
5.1 INTRODUCTION TO ARYLAMINOCOUMARIN
Many coumarin molecules are known in literature but 4-aminocoumarin
is not much reported. The preparation of 4-aminocoumarin and other 4arylaminocoumarins
are pioneered by various research workers.
Apparently it is found that 4-aminocourmarin is prepared by direct
method by removing acidic hydroxyl group (1) with amino group (3) in one
step only, but alternate route is to convert the hydroxyl group (1) into chloro
group (2) and then convert it into amino group (3) by appropriate reagent for
substitution. (Fig. 5.1)
(1)
O O
OH
(2)
O O
The conversion of 4-hydroxy coumarin can also be afforded by a direct
one step method using appropriate arylamine using solvents, without solvents
under conventional heating or by using microwave assisted synthetic strategy.
A small review of current update is included.
O O
Department of Chemistry, Saurashtra University, Rajkot – 360 005 277
Cl
R = H, Alkyl or Aryl
Fig. 5.1
(3)
HN
R