benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine in N,N-dimethyl-formamide T=20°C; 5 h;

in acetonitrile 8 h;

1: 82 percent / thionyl chloride / benzene; dimethylformamide / 12 h / Heating 2: 1.) Mg, ethanol / 1) benzene, CCl4, reflux, 2 - 3 h; 2) benzene, CCl4, reflux, 1 - 2 h 3: 73 percent / acetonitrile / 8 h View Scheme

1: 1.) Mg, ethanol / 1) benzene, CCl4, reflux, 2 - 3 h; 2) benzene, CCl4, reflux, 1 - 2 h 2: 73 percent / acetonitrile / 8 h View Scheme