1: N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile / tetrachloromethane / 4 h / Inert atmosphere; Reflux 2: ammonia / tetrahydrofuran; water / 2 h / Reflux; Inert atmosphere 3: triethyl phosphite / 1,2-dichloro-benzene / 12 h / Reflux; Inert atmosphere 4: methanol; potassium carbonate / tetrahydrofuran / 10 h / Inert atmosphere; Reflux View Scheme