1: With chlorosulphonyl isocyanate; sodium carbonate in dichloromethane 20 h; Heating; 2: With sodium hydroxide in methanol T=20°C; 1 h;

indium tribromide; 1,1,3,3-tetramethyldisiloxane in toluene T=60°C; 15 h; Inert atmosphere;

1: trifluorormethanesulfonic acid / dichloromethane; cyclohexane / 20 °C / Inert atmosphere 2: methanol; sodium hydroxide / 24 h / 20 °C / Inert atmosphere 3: indium tribromide; 1,1,3,3-tetramethyldisiloxane / toluene / 15 h / 60 °C / Inert atmosphere View Scheme

1: methanol; sodium hydroxide / 24 h / 20 °C / Inert atmosphere 2: indium tribromide; 1,1,3,3-tetramethyldisiloxane / toluene / 15 h / 60 °C / Inert atmosphere View Scheme