Thermal fragmentation and rearrangement of some N-phenylbenzamide oxime dervatives II. Synthesis of benzimidazoles

✍ Scribed by Abd El-Aal M. Gaber; Hussni A. Muathen; Layla A. Taib

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 363 KB
• Volume: 91
• Category: Article
• ISSN: 0165-2370
• DOI: 10.1016/j.jaap.2011.01.013

✦ Synopsis

Thermolysis of N-phenylbenzamide oximes I, II and III (R = Cl, NO 2 and OCH 3 ) under nitrogen gives rise to benzimidazoles as the major products (45-52%), in addition to benzonitrile, arylamines, benzoic acid, phenols, benzanilides, 2-phenyl benzoxazoles and carbazoles. In the presence of naphthalene, I gave ␣and ␤-naphthols beside the previous products. Also heating of I under reflux boiling tetralin lead to the formation of 1-hydroxytetralin, ␣-tetralone and 1,1 -bitetralyl as the major products. The isolated products have been interpreted in the terms of a free radical mechanism involving the homolysis of N-O and/or C-N bonds.