الفهرس 
Synthesis of some novel heteroannulatedOnly 14 pages are availabe for public view
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Abstract
The research work in this thesis focused on synthesis of 6-butyl-3- [(dimethylamino)methylene]-3H-pyrano[3,2-c]quinoline-2,4,5(6H)-trione (2), 6-butyl-5,6-dihydro-4-hydroxy-2,5-dioxo-2H-pyrano[3,2-c]quinolone -3-carbonitrile (12), and ethyl 2-(6-ethyl-4,5-dioxo-pyrano[3,2-c] quinolin-3-yl)-2-oxoacetate (20) as the key compounds. The chemical reactivity of these new precursors towards different nucleophiles was studied. The new products were screened for their antioxidant activity.
Part I. Synthesis of some novel heteroannulated pyrano[3,2-c]quinoline-2,5(6H)-diones
Herein we report the synthesis of the novel 6-butyl-3- [(dimethylamino)methylene]-3H-pyrano[3,2-c]quinoline-2,4,5(6H)-trione (2), 6-butyl-5,6-dihydro-4-hydroxy-2,5-dioxo-2H-pyrano[3,2-c]quinoline-
3-carbonitrile (12), and study of their chemical behavior towards different nucleophiles to obtain some novel heteroannulated pyrano[3,2-c] quinolone derivatives from heterocyclization reactions with various binucleophiles.
A clean reaction of N-butylaniline with two equivalents of diethyl malonate under solvent-free conditions gave 4-hydroxypyrano[3,2-c] quinoline-2,5(6H)-dione (1). The desired 3-[(dimethylamino)methylene] pyrano[3,2-c]quinolinone derivative 2 was prepared via thermal condensation of the pyranoquinolinone 1 with dimethylformamide- dimethylacetal.Reaction of enamine 2 with 1,2 binucleophiles such as hydrazine hydrate along with phenylhydrazine in ethanol at room temperature, led to products 3a,b which were present as interconverting hydrazine and hydrazone tautomers. Refluxing hydrazones 3a,b in acetic acid may affect their intramolecular cyclization to afford pyrazolopyranoquinolinone
derivatives 4a,b or compounds Ia,b.
O O O
XH XH O N O N O N
H H2NXH
O O OH
EtOH
N O stirring N O N O
2 Bu
Similarly, reaction of compound 2 with guanidine, cyanoguanidine and thiourea as 1,3-binucleophiles gave the corresponding pyrimido pyranoquinolinones 5a-c. Treatment of enamine 2 with malononitrile as C-nucleophile was carried out in boiling ethanol containing small amount of anhydrous potassium dicarbonate giving rise to pyridinopyrano
quinoline derivative 8
Compound 2 was treated with 3-methyl-1-phenyl-2-pyrazolin-5- one, as cyclic active methylene compounds; in glacial acetic acid containing freshly fused sodium acetate, producing pyrazolopyrano pyranoquinolinone 9. Cyclocondensation of enamine 2 with barbituric acid and thiobarbituric acid, in glacial acetic acid containing freshly fused sodium acetate afforded pyrimidopyranopyranoquinolinone derivatives
10a and 10b.