Formation of dienones on the reaction of cresols, xylenols, and 2-naphthol with nitrogen dioxide: Observation of keto tautomers of nitrophenols

✍ Scribed by Alfred Fischer; N. Mathivanan

• Book ID: 104217507
• Publisher: Elsevier Science
• Year: 1988
• Tongue: French
• Weight: 260 KB
• Volume: 29
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)82064-x

✦ Synopsis

Reaction of o-and p-cresol, the xylenols, and 2-naphthol with nitrogen dioxide gives nitrocyclohexadienones and nitrophenols. Secondary nitrodienones, the keto tautomers of the nitrophenols, have been observed in several cases and are intermediates in the formation of the nitrophenols. 2,4,6_Trisubstituted and polysubstituted phenols give nitrocyclohexa-2,5-dienones on reaction with nitrogen dioxide.1t2*3 In a few instances formation of the 2,4-dienone has been observed or proposed.3 Other phenols on reaction with nitrogen dioxide are reported to give nitrophenols.4 The mechanism for formation of the dienones involves abstraction of the phenolic hydrogen by the nitrogen dioxide followed by combination of the resulting phenoxy radical at an ortho or para position with a second molecule of nitrogen