1: NaH / tetrahydrofuran / 0.5 h / Ambient temperature 2: aq. NaHCO3 / dioxane / 1 h / 80 °C 3: Et3N / ethanol / 1 h / Heating View Scheme

triethylamine in ethanol 1 h; Heating;

1: oxalyl dichloride / N,N-dimethyl-formamide; hexane / 1 h / 20 °C 2: sodium hydride / tetrahydrofuran / 1 h / 20 °C 3: sodium hydrogencarbonate / water; 1,4-dioxane / 1 h / |Reflux 4: ethanol / 1 h / |Reflux View Scheme

1: sodium hydrogencarbonate / water; 1,4-dioxane / 1 h / |Reflux 2: ethanol / 1 h / |Reflux View Scheme

in ethanol 1 h; Reflux;