Rate of Oximation and Extent of Enolization of Alkyl Aryl Ketones¹

One-pot oximation–Beckmann rearrangement of ketones and aldehydes to amides of industrial interest: Acetanilide, caprolactam and acetaminophen

“…an isopropyl-or tertbutyl-moiety, influences the reaction conversion resulting in a nonselective formation of anilides (entries 11 and 12, Table 1). This is due to the competitive formation of the sin and anti-ketoximes that can be ascribed to the similar steric hindrance of phenyl or branched aliphatic groups [33]. In fact, when tert-butyl phenylketone (entry 12, Table 1) was used as substrate the anilide/benzamide ratio detected was bigger than the one observed in the reaction involving isopropylphenylketone (entry 11, Table 1) (78/18 and 20/8, respectively).…”