ammonia; oxygen; sodium; ammonium chloride; trifluoroacetic acid Yield given. Multistep reaction;

With  iron(III) chloride in  water; N,N-dimethyl-formamide T=35°C; 0.5 h;   

Multi-step reaction with 3 steps 1: 74 percent / 1 M NaOH / dioxane / 3 h / Ambient temperature2: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 73: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C  

Multi-step reaction with 3 steps 1: 62 percent / ferric chloride / dioxane; H2O / 0.5 h / 35 °C2: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 73: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C  

Multi-step reaction with 2 steps 1: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 72: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C