Novel and convenient synthesis of polyfunctionalized quinolines, quinolones and their annulation reactions

✍ Scribed by Mei-Xiang Wang; Yong Liu; Zhi-Tang Huang

• Book ID: 104230305
• Publisher: Elsevier Science
• Year: 2001
• Tongue: French
• Weight: 57 KB
• Volume: 42
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)00231-3

✦ Synopsis

The reaction of a-aroylketene dithioacetals with esters of o-aminobenzoic acid under different conditions afforded preferentially 2-methylthio-3-aroylquinolones and 2-anilino-3-aroylquinolines through, respectively, a-aroylketene N,S-acetal and a-aroylketene aminal intermediates. The annulation reaction of 2-methylthio-3-aroylquinolones with hydrazine gave both pyrazolo [3,4-b]quinolone and pyrazolo[4,3-c]quinoline, the selectivity being determined by the reaction conditions employed. Intramolecular cyclocondensation of 2-anilino-3-aroylquinolines produced quino[2,1-b]quinazolines in high yield.