methanesulfonic acid in dichloromethane 0.166667 h;

<b>Multi-step reaction with 5 steps<br /> </b>1: 96.5 percent / Br₂; Fe / CH₂Cl₂ / 2 h / 0 &deg;C<br />2: n-BuLi / tetrahydrofuran; hexane / -78 - 20 &deg;C<br />3: 1.80 g / aq. HCl / tetrahydrofuran; hexane / 20 &deg;C<br />4: 91 percent / Pd(PPh₃)4; aq. Na₂CO₃ / ethanol; 1,2-dimethoxy-ethane / Heating<br />5: 88.9 percent / PhLi / hexane / -78 - 20 &deg;C<br /> <br /> &nbsp;