Beckmann rearrangements of Mannich base and related oximes

Abstract

The oximes of some Mannich bases have been rearranged with phosphorus pentachloride in benzene, to yield β-aminopropionanilides. These β-amino-derivatives, as their methiodides, react easily with aqueous base to yield substituted acrylanilides which can themselves be unambiguously synthesised from acryloyl chloride and the appropriate arylamine. The addition of dimethylamine to the substituted acrylanilides to yield the corresponding substituted β-aminopropionanilides was also achieved. The oximes of aryl vinyl ketones when treated with phosphorus pentachloride in benzene afforded β-chloropropionanilides. These were also prepared by the addition of hydrogen chloride to the appropriate acrylanilide, and by the reaction of β-chloropropionyl chloride with the appropriate arylamine.