1: 5.3 g / toluene / 24 h / Heating 2: 95percent hydrazine hydrate / ethanol / 0.5 h / Heating 3: 0.5 h / 320 °C 4: p-TSA / methanol / 1 h / 110 °C 5: 2 N HCl (aqueous) / methanol / 0.5 h / Heating View Scheme

hydrogenchloride in tetrahydrofuran T=20°C;