hydrogenchloride; water T=120°C; 2.5 h;

Dowex 50W-X8; water in tetrahydrofuran Heating;

hydrogen; palladium in acetic acid 48 h; Yield given;

1: 1.) aq. trifluoroacetic acid; 2.) barium carbonate, bromine / 1.) 15 min; 2.) dioxane, water, from 0 deg C to room temp., 24 h 2: hydrogen / palladium black / aq. acetic acid / 48 h View Scheme

1: aq. Na2CO3 / CH2Cl2 / 0.5 h / Ambient temperature 2: 95 percent / Dowex 50W-X8 resin, water / methanol / 16 h / Ambient temperature; further catalysts and solvents 3: 78 percent / Et3N / CH2Cl2 / 0.17 h / 0 °C 4: 95 percent / H2, sodium acetate / Pd-C / methanol / 10 h 5: 89 percent / Dowex 50W-X8, water / tetrahydrofuran / Heating View Scheme

1: H2 / Pd-C / ethyl acetate / 6 h 2: aq. Na2CO3 / CH2Cl2 / 0.5 h / Ambient temperature 3: 95 percent / Dowex 50W-X8 resin, water / methanol / 16 h / Ambient temperature; further catalysts and solvents 4: 78 percent / Et3N / CH2Cl2 / 0.17 h / 0 °C 5: 95 percent / H2, sodium acetate / Pd-C / methanol / 10 h 6: 89 percent / Dowex 50W-X8, water / tetrahydrofuran / Heating View Scheme

1: saturated sodium bicarbonate / diethyl ether / 18 h / Ambient temperature 2: 89 percent / trifluoroacetic acid / H2O; dioxane / 24 h 3: 1.) barium carbonate, Br2; 2.) Pd black, H2 / 1.) 3:1 dioxane-water, r.t., 36 h; 2.) acetic acid-water, 48 h; View Scheme

1: 85 percent / trifluoroacetic acid / H2O; dioxane / 24 h 2: 1.) barium carbonate, Br2; 2.) Pd black, H2 / 1.) 3:1 dioxane-water, r.t., 36 h; 2.) acetic acid-water, 48 h; View Scheme

1: 89 percent / trifluoroacetic acid / H2O; dioxane / 24 h 2: 1.) barium carbonate, Br2; 2.) Pd black, H2 / 1.) 3:1 dioxane-water, r.t., 36 h; 2.) acetic acid-water, 48 h; View Scheme

barium dihydroxide in water pH=8; regioselective reaction;