1: propanedioic acid monoethyl ester With n-butyllithium in tetrahydrofuran; hexane Inert atmosphereCooling; 2: 2,6-dichloronicotinic acid chloride in tetrahydrofuran; hexane T=-50 - 20°C; 1 h; 3: With hydrogenchloride in tetrahydrofuran; hexane; water

1: 2,6-dichloro-3-carboxypyridine With 1,1'-carbonyldiimidazole in tetrahydrofuran; acetonitrile T=20°C; 2.5 h; 2: malonic acid ethyl ester monopotassium salt With triethylamine; magnesium chloride in acetonitrile T=20°C; 15 h;

1: malonic acid ethyl ester monopotassium salt With magnesium chloride in acetonitrile T=25°C; 0.0833333 h; 2: 2,6-dichloronicotinic acid chloride in acetonitrile T=5°C; 0.5 h; 3: With hydrogenchloride; water; triethylamine more than 3 stages;

1: 2,6-dichloro-3-carboxypyridine With 1,1'-carbonyldiimidazole in tetrahydrofuran 2: propanedioic acid monoethyl ester in tetrahydrofuran 3: With methylmagnesium bromide in tetrahydrofuran Further stages.;

1.1: thionyl chloride / N,N-dimethyl-formamide; chloroform / 17 h / Reflux 2.1: n-butyllithium / hexane; tetrahydrofuran / Inert atmosphere; Cooling 2.2: 1 h / -50 - 20 °C View Scheme

1: in tetrahydrofuran 2: With methylmagnesium bromide in tetrahydrofuran