1: propanedioic acid monoethyl ester With n-butyllithium in tetrahydrofuran T=-78°C; 0.166667 h; 2: 2-chloro-pyridine-5-carbonyl chloride in tetrahydrofuran T=-78°C; 1.08333 h;

3 A molecular sieve; pyridinium chlorochromate in dichloromethane T=20°C; 3 h;

1: malonic acid ethyl ester monopotassium salt With triethylamine; magnesium chloride in ethyl acetate T=70°C; 2: 2-chloro-pyridine-5-carbonyl chloride in ethyl acetate T=50 - 60°C; Product distribution / selectivity;

1: 80 percent / Zn powder / benzene / 2 h / Heating 2: 52 percent / 3 Angstroem molecular sieves; pyridinium chlorochromate / CH2Cl2 / 3 h / 20 °C View Scheme

water; N,N-dimethyl-formamide T=110°C; 10 h; Product distribution / selectivity;