toluene-4-sulfonic acid in benzene T=105°C; 48 h;

toluene-4-sulfonic acid in toluene Dean Stark;

1: 85 percent / AlCl3 / 1,2-dichloro-benzene / 7 h / 95 °C 2: 98 percent / KOH; H2NNH2 / triethylene glycol / 2 h / 200 °C 3: 95 percent / polyphosphoric acid / 2 h / 90 °C 4: 99 percent / p-TsOH / benzene / 48 h / 105 °C View Scheme

1: 95 percent / polyphosphoric acid / 2 h / 90 °C 2: 99 percent / p-TsOH / benzene / 48 h / 105 °C View Scheme

1: 98 percent / KOH; H2NNH2 / triethylene glycol / 2 h / 200 °C 2: 95 percent / polyphosphoric acid / 2 h / 90 °C 3: 99 percent / p-TsOH / benzene / 48 h / 105 °C View Scheme

1: 7-Bromo-1,2,3,4-tetrahydronaphthalene-1-spiro-2'-(1',3'-dioxacyclopentane) With tert.-butyl lithium in tetrahydrofuran; pentane T=-78 - 0°C; 2: carbon dioxide in tetrahydrofuran; pentane T=-78°C; 0.5 h; 3: With hydrogenchloride; water in tetrahydrofuran; pentane T=-78°C;