SYNTHESIS OF SUBSTITUTED 2-PHENYL-4-PIPERIDINONES FROM STYRYL β-DIMETHYLAMINOETHYL KETONES AND THEIR STERIC STRUCTURE

Article abstract of DOI:10.1007/BF00476754

The difficultly obtainable substituted 2-phenyl-4-piperidinones were synthesized by the reaction of styryl β-dimethylaminoethyl ketone hydrochlorides with aqueous solutions of ammonia or alkylamines.It was found using 1H and 13C NMR spectroscopy methods that the cyclization process proceeds with the formation of pure stereoisomers of 4-piperidones with an equatorial disposition of all the substituents in the ring.The temperature for performing the cyclization is dependent on the number and position of the methyl substituents in the molecule of the starting substituted styryl β-dimethylaminoethyl ketones.