1: 5-chloro-3-fluoro-2-iodopyridine With n-butyllithium in hexane; toluene T=-75°C; 1 h; 2: carbon dioxide in hexane; toluene

1: With isopropylmagnesium chloride in tetrahydrofuran T=0°C; 2 h; 2: With iodine in tetrahydrofuran T=-75°C; 1 h;

1: With 2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran T=-75°C; 0.25 h; 2: With methanol

1.1: 91 percent / aq. sodium hydroxide / 20 h / 75 °C 2.1: 97 percent / phosphoryl tribromide / dimethylformamide / 2 h / 130 °C 3.1: isopropylmagnesium chloride / tetrahydrofuran / 2 h / 0 °C 3.2: 59 percent / iodine / tetrahydrofuran / 1 h / -75 °C View Scheme

1.1: 97 percent / phosphoryl tribromide / dimethylformamide / 2 h / 130 °C 2.1: isopropylmagnesium chloride / tetrahydrofuran / 2 h / 0 °C 2.2: 59 percent / iodine / tetrahydrofuran / 1 h / -75 °C View Scheme

1.1: butyllithium; 2,2,6,6-tetramethylpiperidine / tetrahydrofuran / 0.25 h / -75 °C 1.2: methanol 2.1: isopropylmagnesium chloride / tetrahydrofuran / 2 h / 0 °C 2.2: 59 percent / iodine / tetrahydrofuran / 1 h / -75 °C View Scheme