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Chapter – 5 Synthesis and Characterization…..
Recently Hamdi et. al. 56 reported the reaction of 4-hydroxycoumarin in
toluene with a variety of aromatic bis (nucleophilic) compounds, where 3-
(dimethylaminomethylene)-2, 4-chromandione was used as a key
intermediate for the preparation of bis [N-(4-oxocoumarinylmethylene)]-1, 4diamines.
Alternative synthetic procedures and antibacterial activity data of
some of the new compounds were given. Compounds thus prepared, i.e., 1,
3-dihydro-4-(2-hydroxyphenyl)-2H-1, 5-benzodiazepin-2-one, 4-[(2mercaptophenyl)
amino]-2H-1-benzopyran-2-one and 4-[(2-hydroxyphenyl)
amino]-2H-1-benzopyran-2-one were evaluated for their antibacterial activity
against Staphylococcus aureus.
Braccio et. al. 57 obtained the N-substituted tricyclic 2-aminochromone
derivatives by treating the corresponding (methylthio) or (methylsulfinyl)
derivatives with an excess of the properly substituted amines. Compound (1)
(R = R1 = Ph) was synthesized through the reaction of β-naphthol with the
base / POCl3 reagent. The N-substituted 4-aminocoumarin bicyclic and
tricyclic derivatives such as (2) [X = OCH3, Y = H (3)] were prepared by
treating the corresponding chloro derivatives with the excess of properly
substituted amines. Compounds were tested in vitro for their antiproliferative
activity (DNA synthesis inhibition in Ehrlich cells) and cytotoxicity (MTT test in
HeLa cells). The inhibitory properties of three selected compounds (3), (2) (X
= Y = OCH2O) and (4) on protein and RNA syntheses in Ehrlich cells were
also evaluated. Among the twenty seven compounds tested, ten 4aminocoumarin
derivatives and two 2-aminochromone derivatives, (4) and (1)
(R = H, R1 = 4-chlorophenyl) showed an appreciable antiproliferative activity
(IC50 range: 1.74-13.8 µM), whereas only four compounds exhibited a
comparable cytotoxic activity (IC50 range: 4.95-12.9 µM). (Fig. 5.11)
Department of Chemistry, Saurashtra University, Rajkot – 360 005 287