pyridine; thionyl chloride in dichloromethane T=20°C; Substitution; 2 h;

1.1: lithium aluminium tetrahydride / tetrahydrofuran / 6 h / -20 - 20 °C / Inert atmosphere 1.2: 0.17 h / 20 °C 2.1: 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione / dimethyl sulfoxide / 5 h / 20 °C / Inert atmosphere 3.1: diethyl ether / 5 h / 20 °C / Inert atmosphere; Cooling with ice 4.1: 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione / dimethyl sulfoxide / 5 h / 20 °C / Inert atmosphere View Scheme