1: in methanol; dimethyl sulfoxide T=90°C; 8 h; 2: With hydrogenchloride; water T=110°C; 23 h;

1: in aq. phosphate buffer pH=7; 2: With sodium tetrahydroborate; sodium hydroxide T=20°C; 4 h; 3: With hydrogenchloride in water T=110°C; 23 h; Inert atmosphere;