hydrogenchloride in tetrahydrofuran T=55°C; 12 h;

1: 41 percent / zinc iodide; diethyl azodicarboxylate; triphenylphosphine / tetrahydrofuran / 12 h / 25 °C 2: 45 percent / aq. HCl / tetrahydrofuran / 12 h / 55 °C View Scheme

pyridine; 4-(N,N-dimethlyamino)pyridine in dichloromethane 12 h;