Synthesis of 3-indolylazoles and meridianin derivatives from indolyl enaminonit...

• Author(s): Campos, Ana M. F. Oliveira ; Salaheldin, Abdellatif M. ; Paz, Filipe A. Almeida ; Rodrigues, Lígia M.
• Date: 2011
• Persistent ID: http://hdl.handle.net/1822/15115
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Indole; Alkaloids; Enaminonitrile; Meridianins; 3-Indolylazoles
• Document Type: Article
• Language: English

Description

The reaction of indole derivatives with cyanoacetic acid followed by treatment with DMFDMA gave the intermediate indolyl enaminonitriles (3). Further reaction with aminoguanidine yielded 5´-cyanomeridianin analogues (4). The same intermediate reacted with p-methoxyphenylhydrazine to give the pyrazolyl derivative (8). Treatment of (2E)-3-dimethylamino-2-(1H-indol-3-yl)-propenoate (3a) with hydroxylamine hydrochloride in basic medium afforded (5-amino-isoxazol-4-yl)-(1H-indol-3-yl)-methanone (5) and the acrylic acid derivative (6) after a short or a long heating, respectively. Unequivocal structural elucidation of the latter compound was achieved from single-crystal X-ray diffraction studies.