1: 4-pentenecarboxylic acid With 1-hydroxybenzotriazol-hydrate; dicyclohexyl-carbodiimide in dichloromethane T=0°C; 0.583333 h; 2: aniline With triethylamine in dichloromethane T=20°C; 48 h;

in benzene T=25°C; 10 h;

1: 83 percent / tetrahydrofuran / 0.25 h / -78 °C 2: diethyl ether; tetrahydrofuran / 4 h / 20 °C 3: 6 N aq. NaOH / methanol / 0.42 h / Heating View Scheme

1: oxalyl dichloride / benzene / 12 h 2: 82 percent / benzene / 10 h / 25 °C View Scheme