1: H2 / Pd/C / ethyl acetate 2: 41 percent / AcOH / tetrahydrofuran / 48 h / 110 - 120 °C 3: POCl3 / benzene / 1 h / Heating 4: concd. HCl / 1.) 60 deg C, 30 min, 2.) reflux, 10 min 5: EtOCOCl, Et3N / acetone / 0.25 h / 0 °C 6: aq. NaN3 / acetone / 0.5 h / 0 °C 7: benzene / 1 h / Heating 8: 8 N HCl / 0.17 h / Heating 9: methanol / 24 h / 20 °C View Scheme

1: 41 percent / AcOH / tetrahydrofuran / 48 h / 110 - 120 °C 2: POCl3 / benzene / 1 h / Heating 3: concd. HCl / 1.) 60 deg C, 30 min, 2.) reflux, 10 min 4: EtOCOCl, Et3N / acetone / 0.25 h / 0 °C 5: aq. NaN3 / acetone / 0.5 h / 0 °C 6: benzene / 1 h / Heating 7: 8 N HCl / 0.17 h / Heating 8: methanol / 24 h / 20 °C View Scheme

1: EtOCOCl, Et3N / acetone / 0.25 h / 0 °C 2: aq. NaN3 / acetone / 0.5 h / 0 °C 3: benzene / 1 h / Heating 4: 8 N HCl / 0.17 h / Heating 5: methanol / 24 h / 20 °C View Scheme

1: POCl3 / benzene / 1 h / Heating 2: concd. HCl / 1.) 60 deg C, 30 min, 2.) reflux, 10 min 3: EtOCOCl, Et3N / acetone / 0.25 h / 0 °C 4: aq. NaN3 / acetone / 0.5 h / 0 °C 5: benzene / 1 h / Heating 6: 8 N HCl / 0.17 h / Heating 7: methanol / 24 h / 20 °C View Scheme

1: concd. HCl / 1.) 60 deg C, 30 min, 2.) reflux, 10 min 2: EtOCOCl, Et3N / acetone / 0.25 h / 0 °C 3: aq. NaN3 / acetone / 0.5 h / 0 °C 4: benzene / 1 h / Heating 5: 8 N HCl / 0.17 h / Heating 6: methanol / 24 h / 20 °C View Scheme

in methanol T=20°C; 24 h;