1: 91 percent / bromine / CHCl3 / 0.5 h / Ambient temperature 2: 65 percent / CHCl3 / 72 h / Ambient temperature View Scheme

1: 91 percent / bromine / CHCl3 / 0.5 h / Ambient temperature 2: 65 percent / CHCl3 / 72 h / Ambient temperature 3: 96 percent / sodium methoxide / methanol / 1 h / Ambient temperature View Scheme

hydrazinium monoacetate in N,N-dimethyl-formamide T=25°C; 0.166667 h; Yield given;

With  bromine in  chloroform 0.5 h;  Ambient temperature;