1: 5-hydroxy-2-methoxy-pyridine-4-carbaldehyde With potassium carbonate in N,N-dimethyl-formamide T=50°C; 0.166667 h; 2: methyl iodide in N,N-dimethyl-formamide T=50°C; 3 h;

1: 2,5-dimethoxypyridine With methyllithium; diisopropylamine in tetrahydrofuran; diethyl ether T=-40 - 0°C; 2: 1-piperidinecarboxaldehyde in tetrahydrofuran; diethyl ether T=-40°C; 2 h;

1.1: 86 percent / K2CO3 / dimethylformamide / 3 h / 50 °C 2.1: MeLi; diisopropylamine / tetrahydrofuran / 3 h / 0 °C 2.2: 55 percent / tetrahydrofuran / 2 h / -40 °C View Scheme

1: 95 percent / aq. HCl / tetrahydrofuran / 3 h / 50 °C 2: K2CO3 / dimethylformamide / 3 h / 50 °C View Scheme

1.1: MeLi; diisopropylamine / tetrahydrofuran / 3 h / 0 °C 1.2: 62 percent / tetrahydrofuran / 2 h / -40 °C 2.1: 95 percent / aq. HCl / tetrahydrofuran / 3 h / 50 °C 3.1: K2CO3 / dimethylformamide / 3 h / 50 °C View Scheme