4-(N,N-dimethlyamino)pyridine; dicyclohexyl-carbodiimide in dichloromethane Esterification; 4 h;

1: 4-chloro-1H-indole With n-butyllithium in tetrahydrofuran T=0°C; 2: With zinc(II) chloride 3: ethyl bromoacetate

1: 72.2 percent / acetic acid / 5 - 20 °C 2: 87.3 percent / dimethylformamide; H2O / 6 h / Heating 3: 94.1 percent / aq. potassium hydroxide / methanol / 16 h / Heating 4: 74.4 percent / N,N'-dicyclohexylcarbodiimide; N,N-dimethylaminopyridine / CH2Cl2 / 4 h View Scheme

1: dimethylformamide / 80 h / 110 °C 2: 243.3 g / aq. hydrazine hydrate / tetrahydrofuran; methanol / 10 - 20 °C 3: 72.2 percent / acetic acid / 5 - 20 °C 4: 87.3 percent / dimethylformamide; H2O / 6 h / Heating 5: 94.1 percent / aq. potassium hydroxide / methanol / 16 h / Heating 6: 74.4 percent / N,N'-dicyclohexylcarbodiimide; N,N-dimethylaminopyridine / CH2Cl2 / 4 h View Scheme

1: 87.3 percent / dimethylformamide; H2O / 6 h / Heating 2: 94.1 percent / aq. potassium hydroxide / methanol / 16 h / Heating 3: 74.4 percent / N,N'-dicyclohexylcarbodiimide; N,N-dimethylaminopyridine / CH2Cl2 / 4 h View Scheme

1: 243.3 g / aq. hydrazine hydrate / tetrahydrofuran; methanol / 10 - 20 °C 2: 72.2 percent / acetic acid / 5 - 20 °C 3: 87.3 percent / dimethylformamide; H2O / 6 h / Heating 4: 94.1 percent / aq. potassium hydroxide / methanol / 16 h / Heating 5: 74.4 percent / N,N'-dicyclohexylcarbodiimide; N,N-dimethylaminopyridine / CH2Cl2 / 4 h View Scheme

1: 94.1 percent / aq. potassium hydroxide / methanol / 16 h / Heating 2: 74.4 percent / N,N'-dicyclohexylcarbodiimide; N,N-dimethylaminopyridine / CH2Cl2 / 4 h View Scheme

acetic acid; zinc T=100°C;

sodium hydroxide Yield given;