1: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 7 2: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C 3: 1.) Na/NH3, 2.) NH4Cl, 3.) trifluoroacetic acid, O2 View Scheme

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  

With  iron(III) chloride in  1,4-dioxane; water T=35°C; 0.5 h;   

With  sodium hydroxide in  1,4-dioxane 3 h;  Ambient temperature;