1: triethylamine / ethyl acetate / 1 h / 0 °C / |Inert atmosphere 2: sodium tetrahydroborate / ethyl acetate; N,N-dimethyl-formamide / 0 °C / |Inert atmosphere 3: 4-(N,N-dimethlyamino)pyridine; pyridine / 24 h / 20 °C 4: hydrazinium monoacetate / N,N-dimethyl-formamide / 0.5 h / 20 °C View Scheme

1: 4-(N,N-dimethlyamino)pyridine; pyridine / 24 h / 20 °C 2: hydrazinium monoacetate / N,N-dimethyl-formamide / 0.5 h / 20 °C View Scheme