1: hydroxylamine / acetonitrile; water / 14 h / 23 °C 2: 4-nitrophenylsulfonyl chloride; N-ethyl-N,N-diisopropylamine / tetrahydrofuran / 2 h / 0 °C / |Inert atmosphere View Scheme

hydroxylamine in water; acetonitrile T=23°C; 14 h;