1: 2-ethoxy-3-fluorophenol With potassium carbonate in acetone 0.5 h; Inert atmosphereReflux; 2: diethyl sulphate in acetone T=56°C; 5 h; Inert atmosphere;

sodium hydroxide in ethanol T=10°C; 3 h; Heating / reflux; Product distribution / selectivity;

AlCl3, aluminium chloride in dichloromethane 2 h; Heating / reflux;

1: With formic acid; dihydrogen peroxide in dansyl cadaverine T=20 - 40°C; 24 h; 2: With potassium hydroxide in methanol T=10 - 20°C; 1 h; Industry scale; 3: With hydrogenchloride in water pH=2 - 4;

1.1: potassium carbonate / 1-methyl-pyrrolidin-2-one / 30 - 70 °C / Inert atmosphere 1.2: 60 - 80 °C / Inert atmosphere 2.1: 1-methyl-pyrrolidin-2-one / 180 - 210 °C / Inert atmosphere 2.2: 60 - 80 °C / Inert atmosphere 2.3: 100 - 110 °C / Inert atmosphere 3.1: N-benzyl-N,N,N-triethylammonium chloride; potassium permanganate / dansyl cadaverine / 2 h / 0 °C 4.1: formic acid; dihydrogen peroxide / dansyl cadaverine / 24 h / 20 - 40 °C 4.2: 1 h / 10 - 20 °C / Industry scale 4.3: pH 2 - 4 View Scheme

1.1: 1-methyl-pyrrolidin-2-one / 180 - 210 °C / Inert atmosphere 1.2: 60 - 80 °C / Inert atmosphere 1.3: 100 - 110 °C / Inert atmosphere 2.1: N-benzyl-N,N,N-triethylammonium chloride; potassium permanganate / dansyl cadaverine / 2 h / 0 °C 3.1: formic acid; dihydrogen peroxide / dansyl cadaverine / 24 h / 20 - 40 °C 3.2: 1 h / 10 - 20 °C / Industry scale 3.3: pH 2 - 4 View Scheme

1.1: N-benzyl-N,N,N-triethylammonium chloride; potassium permanganate / dansyl cadaverine / 2 h / 0 °C 2.1: formic acid; dihydrogen peroxide / dansyl cadaverine / 24 h / 20 - 40 °C 2.2: 1 h / 10 - 20 °C / Industry scale 2.3: pH 2 - 4 View Scheme

1.1: AlCl3, aluminium chloride / chlorobenzene / 120 °C / |Inert atmosphere; |Large scale 2.1: potassium carbonate; potassium fluoride / acetone / 0.42 h / 56 °C / |Inert atmosphere 2.2: 5.5 h / 56 °C / |Inert atmosphere 3.1: 3-chloro-benzenecarboperoxoic acid / tert-butyl methyl ether; chlorobenzene / 5 h / 80 °C / |Inert atmosphere View Scheme

1.1: potassium carbonate; potassium fluoride / acetone / 0.42 h / 56 °C / |Inert atmosphere 1.2: 5.5 h / 56 °C / |Inert atmosphere 2.1: 3-chloro-benzenecarboperoxoic acid / tert-butyl methyl ether; chlorobenzene / 5 h / 80 °C / |Inert atmosphere View Scheme