الفهرس 
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Abstract
Chalcones, considered to be the precursor of flavonoids and isoflavonoids,
are abundant in edible plants. They consist of open-chain flavonoids in which the
two aromatic rings are joined by a three-carbon α, β-unsaturated carbonyl system.
Studies revealed that compounds with a chalcone-based structure have antiinflammatory,
antibacterial, antifungal, and antitumor activities.
The reaction sequences employed for synthesis of the target thiazolidine-2,4-
dione (54) and 4-thioxo-thiazolidine-2-one (55) are illustrated in Scheme 1.
Chalcones 57a-e were synthesized by a base-catalyzed Claisen-Schmidt
reaction between substituted acetophenone and terephthalaldehyde in 86-91%
yields (Scheme 2).
English Summary
ii
Chalcones 57a-e were subjected to Knoevenagel condensation with 54 in the
presence of catalytic amount of piperidine and acetic acid to afford 58a-e in 80-
86% yields (Scheme 3).
Chalcones 57a-e were subjected to Knoevenagel condensation with 55 in the
presence of catalytic amount of piperidine and acetic acid to afford 59a-e in 78-
86% yields (Scheme 4).
The chalcone 61 was synthesized by a base-catalyzed reaction between
acetophenone and 6-nitronicotinaldehyde in 80% yield. Bromination of 61 in
chloroform afforded the corresponding 2,3-dibromochalcone 62. Treatment of 62
with dry benzene in the presence of triethylamine afforded 63 (Scheme 5).
hydrazine hydrate or phenyl hydrazine in
ethanol to afford the Δ2-pyrazoline 64 in 70% yield, and N-phenyl-Δ2-pyrazoline
65 in 73% yield. Condensation of 61 with hydroxylamine hydrochloride, thiourea,
or urea in ethanolic sodium hydroxide solution gave 4,5-dihydroisoxazole 66 in
80% yields, 5,6-dihydropyrimidine-2(1H)-thione 67 in 75% yield, and 5,6-
dihydropyrimidine-2(1H)-one 68 in 73% yield (Scheme 6).
The pyrazole derivatives 69-71 were obtained by refluxing of
dibromochalcone 62 with phenylhydrazine, nicotinichydrazide, or 2-
hydrazinylquinoline in dry pyridine. (Scheme 7).