1: CH2Cl2; diethyl ether / 24 h / Ambient temperature 2: 1.) Br2, 2.) conc. HCl / 1.) CH2Cl2,, RT, 30 min, 2.) reflux, 1 d View Scheme

1: CH2Cl2; diethyl ether / 24 h / Ambient temperature 2: 1.) Br2, 2.) conc. HCl / 1.) CH2Cl2,, RT, 30 min, 2.) reflux, 1 d 3: 41 percent / CH2Cl2; diethyl ether / 0.17 h / Ambient temperature View Scheme

Multi-step reaction with 2 steps 1: (i) NaNO2, aq. HCl, (ii) /BRN= 471705/, Cu2Cl2, acetone2: 2,4,6-trimethyl-pyridine / benzene / 24 h / Heating