1: 67 percent / H2O; ethanol / 3 h / Heating 2: 88 percent / cc. H2SO4, acetic acid, H2O / 3.5 h / Heating 3: 74 percent / cc. H2SO4 / 7 h / Heating 4: 41 percent / 5 h / 135 - 140 °C View Scheme

T=135 - 140°C; 5 h;

1: 74 percent / cc. H2SO4 / 7 h / Heating 2: 41 percent / 5 h / 135 - 140 °C View Scheme

1: 88 percent / cc. H2SO4, acetic acid, H2O / 3.5 h / Heating 2: 74 percent / cc. H2SO4 / 7 h / Heating 3: 41 percent / 5 h / 135 - 140 °C View Scheme