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Abstract I-Summary of the original work: 1.1. Syntheses of polyfunctionally substituted quinolin-4(5H)-one derivatives: 2,4-Dichloroquinoline-3-carbonitrile (119) reacted with appropriate secondary amines 159a-d in DMF solution at room temperature did not afford the 2-alkyl amino-4- chloroquinoline-3-carbonitrile 160 but gave instead of the expected isomeric structure, 4- 2-Chloro-4-( 4-methypiperazino)quinoline-3-carbonitrile(161a) reacted with sodium azide in DMF at 80°C, the ring-closed tetrazolo[ 1 ,5-a ]quinoline (163) was isolated instead of the isomeric azidoquinoline 162, based on the absence of an azido band in IR spectrum. Acid hydrolysis of 2-chloro-4( 4-rnethylpiperidino )quinoline- 3-carbonitrile 161 b produced in one step 4-( 4-methylpiperidino )-2-oxo-] ,2-dihydroquinoline-3-carbonitrile (165) and did not give the isomeric quinolin-4-one 164~ Alkylation of (165) with alkyl halide 166a-c in the presence of K2C01 afforded respectively, the N-alkyl derivatives 167a-c which refluxed with an excess of hydrazine hydrate (80%) for 12h afforded the novel 5-alkyl- 3-amino-pyrazolo[ 4,3-c ]quinolines-4-ones 170a-c, their structures were confirmed on the basis of consistent elemental and spectral data. Substituted pyrazoio[4,3-c]quinolin-2-one 170a,b reacted with sodium nitrite In 70% solution of H2S04 at -5°C followed by the reaction of pyrazoloquinoline diazonium sulphate with an aqueous solution of sodium azide did not give the ring-ciosed pyrazolotetrazoloquinoline 173 but instead gave the isomeric azidopyrazoloquinoline 171a,b which refluxed with triphenyl phosphine in toluene for an hour afforded the open- chain 5-methyl- 3-[(triphenylphosphoranylidene )-amino]-] H-pyrazoio[ 4,3-c ]quinolines- |