1: With triethylamine in dichloromethane T=0 - 20°C; 4 h; 2: With sodium acetate in acetic acid 15 h; Heating;

1.1: oxalyl chloride; DMF / CH2Cl2 / 12 h / 20 °C 2.1: Et3N / CH2Cl2 / 4 h / 0 - 20 °C 2.2: 93 percent / AcONa / acetic acid / 15 h / Heating View Scheme

1.1: NaH / tetrahydrofuran / 0 - 20 °C 1.2: 92 percent / tetrahydrofuran / 13 h / 20 °C 2.1: 93 percent / NaOH / methanol / 0.42 h / Heating 3.1: H2 / Pd/C / methanol / 24 h / atmospheric pressure View Scheme