toluene-4-sulfonic acid; sodium hydrogensulfite in isobutyramide T=115°C;

iodine; potassium carbonate in N,N-dimethyl-formamide T=70°C; 17 h; Product distribution / selectivity;

1.1: sodium hydroxide; dihydrogen peroxide / tetrahydrofuran; water / 70 °C 1.2: 3 h / 20 °C 1.3: 16 h / 20 °C 2.1: N,N-dimethyl-formamide / 1 h / 70 °C 2.2: 16 h / 70 °C View Scheme

1.1: diethyl ether / 2 h / 170 °C 2.1: sodium hydroxide; dihydrogen peroxide / tetrahydrofuran; water / 70 °C 2.2: 3 h / 20 °C 2.3: 16 h / 20 °C 3.1: N,N-dimethyl-formamide / 1 h / 70 °C 3.2: 16 h / 70 °C View Scheme

1.1: hydrogenchloride / diethyl ether / 1.5 h / 0 - 10 °C 2.1: diethyl ether / 2 h / 170 °C 3.1: sodium hydroxide; dihydrogen peroxide / tetrahydrofuran; water / 70 °C 3.2: 3 h / 20 °C 3.3: 16 h / 20 °C 4.1: N,N-dimethyl-formamide / 1 h / 70 °C 4.2: 16 h / 70 °C View Scheme

1: potassium carbonate / ethanol / 24 h / |Reflux 2: sodium hydrogensulfite; toluene-4-sulfonic acid / N,N-dimethyl acetamide / 14 h / 150 °C View Scheme