1: 84 percent / CHCl3 / 4 h / Ambient temperature 2: sat. NaHCO3 / H2O View Scheme

1: 74 percent / Na2SO3 / pH 8-9 2: 58 percent / Na2CO3 / H2O / 4 h / Heating; pH neutr. 3: 85 percent / pyridine, SOCl2 / 3 h / Heating 4: 85 percent / triethylamine / benzene / 24 h / Ambient temperature 5: 83 percent / ethanol / 96 h / Ambient temperature View Scheme