in ethanol 96 h; Ambient temperature;

1: 74 percent / cc. H2SO4 / 4 h / 25 - 30 °C 2: 79 percent / SOCl2 / dimethylformamide / 24 h / Ambient temperature 3: 74 percent / Na2SO3 / pH 8-9 4: 58 percent / Na2CO3 / H2O / 4 h / Heating; pH neutr. 5: 85 percent / pyridine, SOCl2 / 3 h / Heating 6: 85 percent / triethylamine / benzene / 24 h / Ambient temperature 7: 83 percent / ethanol / 96 h / Ambient temperature 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

in ethanol 96 h; Ambient temperature;