1: pyridine 2: LiBr / dimethylsulfoxide / 1.5 h / 70 °C 3: 1.) n-BuLi, 2.) HMPA / 1.) THF, from 5 deg C to 10 deg C, 1 h, 2.) THF, 19 h 4: aq. H2SO4 5: PBr3, pyridine / diethyl ether 6: 1.) EtMgBr, 2.) CuI / 1.) THF, 40 deg C, 30 min, 2.) THF, a) 50 deg C, 3 h, b) RT, overnight 7: H2, quinoline / Pd/BaSO4 / ethyl acetate 8: lithium t-butyl thiolate / dimethylformamide View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: 1.) LiN(iPr)2, 2.) HMPA / 1.) THF, -70 deg C, 10 min, 2.) THF, a) -70 deg C, 7 h, b) 90 deg C, 16 h<br />2: aq. H₂SO₄ <br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: p-TsOH / 3 h / 0 - 10 &deg;C<br />2: 1.) LiN(iPr)2, 2.) HMPA / 1.) THF, -70 deg C, 10 min, 2.) THF, a) -70 deg C, 7 h, b) 90 deg C, 16 h<br />3: aq. H₂SO₄ <br /> <br /> &nbsp;