Phase Transfer Catalyzed C- vs O-Alkylation of 3-Methyl-1-phenyl-2-pyrazolin-5-one in the Absence or Presence of Carbon Disulphide

Abstract

3-Methyl-1-phenyl-2-pyrazolin-5-one (1) was treated with different bromoorganic compounds such as benzyl bromide, 1.3-dibromopropane,methyl bromoacetate, bromoacetaldehyde diethylacetal as ablating agents either in the absence or in the presence of carbon disulphide and under phasetransfer catalysis conditions aimed at studying the reactivity of the title compound with respect to Cvs 0alkylation .In continuation of our previous work on phase-transfer catalysis ' and pyrazolone chemishy ,2'3 we undertook to study the reactivity of C4-1,s 0-alkylation towards some bromoorganic compounds as alkylating agents in the absence or in the presence of carbon disulphide under phase-transfer catalysis ( PTC ) condit~ons as a versatile tool compared with the classical basecatalyzed