1: 86 percent / 1-methyl-pyrrolidin-2-one / 1 h / 90 - 100 °C 2: 100 percent / aqueous sulfuric acid / 4.5 h / 130 - 135 °C 3: 61 percent / triphenylphosphine; diethyl azodicarboxylate / tetrahydrofuran / 16 h / 20 °C 4: hydrogen / Pd/C / methanol / atmospheric pressure 5: aq. phosphate buffer / 37 °C / pH 7.4 View Scheme

1: 86 percent / 1-methyl-pyrrolidin-2-one / 1 h / 90 - 100 °C 2: 100 percent / aqueous sulfuric acid / 4.5 h / 130 - 135 °C View Scheme

lithium bromide in acetone Reflux;