1: With 4-(N,N-dimethlyamino)pyridine; N-ethyl-N,N-diisopropylamine; p-toluenesulfonyl chloride in 1,2-dichloro-ethane T=20°C; 1 h; 2: With hydroxylamine hydrochloride; N-ethyl-N,N-diisopropylamine in 1,4-dioxane; water T=37°C; 120 h; Further stages.;