1: 65 percent / POCl3, pyridine / dimethylformamide / 1 h / 0 °C 2: 75 percent / tetrahydrofuran / 2 h / Ambient temperature 3: 69 percent / ammonium acetate / acetic acid / 3 h / Heating 4: 72 percent / boron tribromide / CH2Cl2; 1,2-dichloro-ethane / 0.5 h / Heating View Scheme

With  palladium on activated charcoal in  xylene 2 h;  Heating;   

Multi-step reaction with 2 steps 1: 77 percent / conc. aq. NH4OH / Ambient temperature2: 70 percent / 5percent Pd/C / xylene / 2 h / Heating  

Multi-step reaction with 2 steps 1: 65 percent / POCl3, pyridine / dimethylformamide / 1 h / 0 °C2: 75 percent / tetrahydrofuran / 2 h / Ambient temperature  

Multi-step reaction with 3 steps 1: 65 percent / POCl3, pyridine / dimethylformamide / 1 h / 0 °C2: 75 percent / tetrahydrofuran / 2 h / Ambient temperature3: 69 percent / ammonium acetate / acetic acid / 3 h / Heating  

With  pyridine; trichlorophosphate in  N,N-dimethyl-formamide T=0°C; 1 h;