1: Reduced nicotinamide-adenine dinucleotide; NADPH; Citrobacter sp. N-ethylmaleimide reductase / dimethyl sulfoxide / 22 h / 30 °C / pH 7 / Enzymatic reaction; Aqueous phosphate buffer 2: potassium hydroxide; water / 6 h / 25 °C 3: hydrogen / Raney Nickel / water / 30 °C 4: acetic acid / ethanol / 35 °C / pH 7.5 View Scheme