in dimethylacetamide (DMAC) T=25°C; 2 h;

thionyl bromide T=20°C; 24 h; Neat (no solvent);

hydrogen bromide; acetic acid in water T=20°C; 96 h;

in N,N-dimethyl acetamide; hydrogen bromide; acetonitrile; benzene

bromine in acetic acid

in methanol 2 h; Heating;

meta-chloroperoxybenzoic acid; bromine in acetic acid 6 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: 1.) Ph3P, 2.) NaOMe / 1.) DMF, 60 deg C, 3 h, 2.) DMF, 10 h 2: 34 percent / 2 h / 150 °C 3: 1.) O3, 2.) Me2S / 1.) CH2Cl2, MeOH, -78 deg C, 30 min, 2.) CH2Cl2, MeOH, 0 deg C, 2 h 4: 63 percent / NaBH4 / CH2Cl2; propan-2-ol / 0.5 h / -10 °C 5: 77 percent / 1N aq. NaOH / dimethylformamide / 4 h / Ambient temperature 6: 1.) 47percent aq. HBr, 2.) Ph3PBr2 / 1.) EtOH, reflux, 15 min, 2.) DMF, RT, 4 h View Scheme

1: 34 percent / 2 h / 150 °C 2: 1.) O3, 2.) Me2S / 1.) CH2Cl2, MeOH, -78 deg C, 30 min, 2.) CH2Cl2, MeOH, 0 deg C, 2 h 3: 63 percent / NaBH4 / CH2Cl2; propan-2-ol / 0.5 h / -10 °C 4: 77 percent / 1N aq. NaOH / dimethylformamide / 4 h / Ambient temperature 5: 1.) 47percent aq. HBr, 2.) Ph3PBr2 / 1.) EtOH, reflux, 15 min, 2.) DMF, RT, 4 h View Scheme

1: 63 percent / NaBH4 / CH2Cl2; propan-2-ol / 0.5 h / -10 °C 2: 77 percent / 1N aq. NaOH / dimethylformamide / 4 h / Ambient temperature 3: 1.) 47percent aq. HBr, 2.) Ph3PBr2 / 1.) EtOH, reflux, 15 min, 2.) DMF, RT, 4 h View Scheme