1: 5-bromo-1H-indole-2,3-dione With sodium hydride in N,N-dimethyl-formamide; mineral oil T=0°C; 2 h; 2: benzyl bromide in N,N-dimethyl-formamide; mineral oil T=0 - 20°C; 2 h;

potassium carbonate in N,N-dimethyl-formamide T=80°C;

potassium carbonate in N,N-dimethyl-formamide 0.0833333 h; microwave irradiation;