SYNTHESIS OF SUBSTITUTED BENZENES FROM ALPHA-METHYLENE KETONES

A new general method for the synthesis of substituted benzenes from cy clic ketones having active methylene groups via the corresponding hydr oxymethylene ketones and enamino-ketones has been developed. Formylati on of these ketones with ethyl formate followed by enamination with py rrolidine produces enamino-ketones which on reaction with threefold ex cess of malononitrile in boiling benzene in the presence of ammonium a cetate in acetic acid gives the substituted benzenes in good yield. Th e reaction has been extended to aliphatic and aromatic ketones having active methylene groups to give substituted benzenes and biphenyls, re spectively.