Multi-step reaction with 4 steps 1.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 2 h / 20 °C2.1: tetrabutyl ammonium fluoride / acetonitrile3.1: sodium hydride / tetrahydrofuran / 1 h3.2: |Darkness4.1: hydrogenchloride / tetrahydrofuran; water / 4 h