Thesis (M.Sc.)--Chulalongkorn University, 2002

Sodium bromide/sodium hypochlorite are innovative and safe brominating agents for aromatic compounds that contain activating substituents. A halogenation process, in which sodium hypochlorite is utilized, was optimized on laboratory scale. Halogenated compounds were synthesized by a halogenation reaction in 2 phases (aqueous and organic solvent) of aromatic compounds such as diphenyl ether, phenol and toluene in the presence of acetic acid and sodium bromide salt/sodium hypochlorite which was oxidizing agent with isooctane as a solvent at room temperature. Halogenated compounds were identified by spectroscopic techniques such as infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectrometry. The bromination of diphenyl ether gave 94% p-dibromodiphenyl ether using mole ratio of substrate, sodium bromide and sodium hypochlorite as 1:10:16 and reaction time for 2 hours. The halogenation of phenol in the presence of tetrabutyl ammoniumtetrafluoroborate as a phase transfer gave 87% 2,4,6-trichlorophenol using a mole ratio of substrate, sodium bromide and sodium hypochlorite as 1:0:8 and gave 50% tribromophenol using a mole ratio of substrate, sodium bromide and sodium hypochlorite as 1:5:8 and reaction time for 2 hours. The bromination of toluene gave 83% dibromotoluene using a mole ratio of substrate, sodium bromide and sodium hypochlorite as 1:5:8 and reaction time for 4 hours.