REACTIONS OF ORTHO-HALOACETOPHENONES WITH CARBON-DISULFIDE AND PHENYLISOTHIOCYANATE

O-Haloacetophenones 1 react with carbon disulfide in the presence of sodium hydride and an alkylating reagent to ketene S,S-acetals 3 and 4. The formation of 1-thiochromones 5 is possible, when the reaction is carried out at 100°. Treatment of 3a with aniline and guanidine, respectively, leads to the ketene N,N-acetal 6 and the 2-aminopyrimidine 7, respectively Reaction of 1 with phenyl isothiocyanate/sodium hydride and following alkylation gives ketene S,N-acetals 9, thiazolidones 14 and thiazolidine 15. Cyclisation of 9 in a basic medium forms the 4(1H)-quinolones 11. The physical properties of synthesized compounds are characterized by means of mass, 1H NMR, and IR spectra. The possible modes of formation are discussed. © 1979.