sodium hydroxide; N-benzyl-N,N,N-triethylammonium chloride T=40 - 50°C; 3 h;

bromine bromate; sulfuric acid in benzene T=22 - 25°C; 15 h;

1: 78 percent / 50percent aq. NaOH, benzyltriethylammonium chloride (TEBA) / 3 h / 40 - 50 °C 2: 20 percent / bromate-bromide solution, 20percent aq. H2SO4 / benzene / 15 h / 22 - 25 °C View Scheme