1.1: 1,1'-carbonyldiimidazole / tetrahydrofuran / 55 - 60 °C / |Inert atmosphere 1.2: 20 °C / |Inert atmosphere 2.1: 4-methyl-morpholine; 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholin-4-ium chloride / ethyl acetate / 20 °C / |Inert atmosphere 3.1: sodium hydroxide; water / methanol / 24 h / 40 - 45 °C / |Inert atmosphere View Scheme

1: 2-carboxypyrazine With 1,1'-carbonyldiimidazole in tetrahydrofuran T=55 - 60°C; Inert atmosphere; 2: L-α-cyclohexylglycine potassium salt in tetrahydrofuran; tert-butyl alcohol T=20°C; Inert atmosphere;