hydrogenchloride; 1,8-diazabicyclo[5.4.0]undec-7-ene 1.) DMF, a.) RT, 30 min, b.) -20 deg C, 30 min, c.) RT, 1.5 h, 2.) reflux, 3 h; Yield given. Multistep reaction;

1: DBU, 4A sieves / dimethylformamide; benzene / a.) -15 deg C, 1 h, b.) RT, 18 h 2: 5percent H2SO4 / 3 h / Heating 3: 21 percent / I2, 1N HNO3 / CHCl3 / 1.) reflux, 4 h, 2.) 5 deg C, 16 h View Scheme

1: 88 percent / Et3N / butan-1-ol / 24 h / Heating 2: NaOAc, AcOH / H2O / Ambient temperature 3: 74.5 percent / Zn, NH4Cl / tetrahydrofuran; methanol / 0.5 h 4: 1.) concd aq. HCl, 2.) 0.6 N aq. HCl / 1.) DMF, 3.5 h, 2.) rt, 30 min 5: 76 percent / 1 N aq. HCl / 1 h / Heating View Scheme

Multi-step reaction with 2 steps 1: 88 percent / Et3N / butan-1-ol / 24 h / Heating2: NaOAc, AcOH / H2O / Ambient temperature  

Multi-step reaction with 3 steps 1: 88 percent / Et3N / butan-1-ol / 24 h / Heating2: NaOAc, AcOH / H2O / Ambient temperature3: 74.5 percent / Zn, NH4Cl / tetrahydrofuran; methanol / 0.5 h  

Multi-step reaction with 4 steps 1: 88 percent / Et3N / butan-1-ol / 24 h / Heating2: NaOAc, AcOH / H2O / Ambient temperature3: 74.5 percent / Zn, NH4Cl / tetrahydrofuran; methanol / 0.5 h4: 1.) concd aq. HCl, 2.) 0.6 N aq. HCl / 1.) DMF, 3.5 h, 2.) rt, 30 min  

Multi-step reaction with 2 steps 1: 91 percent / tetrabutylammonium fluoride / tetrahydrofuran / 0.5 h2: 1.) Dowex 2(OH-) resin, 2.) 1N HCl / 1.) acetone, water, RT, 24 h  

Multi-step reaction with 2 steps 1: DBU, 4A sieves / dimethylformamide; benzene / a.) -15 deg C, 1 h, b.) RT, 18 h2: 5percent H2SO4 / 3 h / Heating