N-ethyl-N,N-diisopropylamine; HATU in N,N-dimethyl-formamide T=20°C;

1: 2-pyridinecarboxylic acid chloride With triethylamine in dichloromethane T=0°C; 0.25 h; Inert atmosphere; 2: p-aminobenzoic acid methyl ester in dichloromethane T=0 - 20°C; 2.75 h; Inert atmosphere;

1.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 1.25 h / 0 °C / |Inert atmosphere 2.1: triethylamine / dichloromethane / 0.25 h / 0 °C / |Inert atmosphere 2.2: 2.75 h / 0 - 20 °C / |Inert atmosphere View Scheme