1: With triethylamine; trichlorophosphate in tetrahydrofuran T=0 - 20°C; Retro Strecker method; 6 h; Heating / reflux; 2: With hydroxylamine hydrochloride in tetrahydrofuran; water T=20°C; 16 h; 3: With hydrogenchloride; sodium hydroxide Product distribution / selectivity; more than 3 stages;