1: With 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; 1,3-Diiodo-5,5-dimethyl-2,4-imidazolidinedione in dichloromethane T=0 - 20°C; 1 h; Inert atmosphere; 2: With ammonia; iodine in dichloromethane; water T=20°C; 3 h; Inert atmosphere;