1: ethyl acetate / -5 °C / Inert atmosphere 2: phenol / 4.5 h / 50 °C 3: penicillin G acylase / water / 37 °C / pH 8 - 8.5 / aq. acetate buffer; Enzymatic reaction 4: tetrahydrofuran; water / 6.5 h / 25 °C / pH 6.8 - 7.2 5: sulfuric acid / water / 5 °C / pH 1 - 2 View Scheme

1: ethyl acetate / -5 °C / Inert atmosphere 2: phenol / 4.5 h / 50 °C 3: penicillin G acylase / water / 37 °C / pH 8 - 8.5 / aq. acetate buffer; Enzymatic reaction 4: tetrahydrofuran; water / 6.5 h / 25 °C / pH 6.8 - 7.2 View Scheme