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Abstract This investigation describes the synthesis of 2-substitutedanilino-4(3H)-quinazolinones (IVa-h) starting from 2-chloro-4(3H)-quinazolinone (III). Subsequent cyclization of compounds IVa-h with ethyl bromoacetate in the presence of a solution of potassium hydroxide in absolute ethanol gave 1-(substitutedphenyl)-1,2,3,5-tetrahydroimidazo[2,1-b]quinazoline-2,5- diones (Va-h). Furthermore, 2-chloro-4(3H)-quinazolinone (III) was converted to ethyl 2-chloro-4-oxo-3,4-dihydro-3-quinazolinylacetate (VI) through reaction with ethyl bromoacetate in the presence of potassium carbonate in dimethylformamide.Then, compound VI was refluxed with m-toluidine in ethanol to yield 1-(m-tolyl)-1,2,3,5-tetrahydroimidazo[2,1-b]quinazoline-2,5- dione (Vh). The study also describes the synthesis of α,β-unsaturated ketones (chalcones) VIIa-d starting from 2-(4-acetylanilino)-4(3H)-quinazolinone and certain aromatic aldehydes in the presence of sodium hydroxide in absolute ethanol. Cyclization of the chalcone VIId with hydrazine hydrate in the presence of absolute ethanol gave the pyrazoline derivative VIII. Moreover, the construction of quinazoline bearing oximes (XIIa,b), thiosemicarbazones XIIIa1, b1, semicarbazones XIIIa2, b2 starting from 4-(4 or 3-acetylanilino)quinazoline (XIa,b).< In addition, the synthesis of quinazoline carrying pyridone derivatives XIVa1, b1 and aminopyridine derivatives XIVa2, b2 was accomplished by reaction of XIa,b with ethyl cyanoacetate or malononitrile respectively. Besides, the chalcones XVa1-4, b1-4 were synthesized starting from 4-(4 or 3-acetylanilino)quinazoline (XIa,b). Chalcones XVa1,4, b1,4 were cyclized with hydrazine hydrate in absolute ethanol to give pyrazoline derivatives XVIa1,2, b1,2. < The antiinflammatory activity of six compounds VIII, XIIIb1 , XIVa1, XIVb2 , XVIa2 and XVIb1 was also inspected. The results revealed that the test compounds possess a marked antiinflammatory activity, and they were more potent than the standard diclofenac sodium. Screening for the antihypertensive activity of four compounds Vb, Vd, Ve and Vh was performed. The test compounds showed a significant antihypertensive activity, but they were less potent than the standard doxazocin mesylate. |