hydrogen; ammonium formate; palladium on activated charcoal in ethanol 6 h;

1: 3-fluoro-4-chloro pyridine With 2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran; hexane T=-75°C; 0.166667 h; 2: carbon dioxide in tetrahydrofuran; hexane

1.1: LDA / tetrahydrofuran; hexane / 2 h / -75 °C 1.2: 57 percent / 1,1,2-trichloro-2,2,1-trifluoroethane / tetrahydrofuran; hexane 2.1: BuLi; 2,2,6,6-tetramethylpiperidine / tetrahydrofuran; hexane / 0.17 h / -75 °C 2.2: 71 percent / tetrahydrofuran; hexane View Scheme