sodium tetrahydroborate; palladium dichloride in methanol T=20°C; 1 h;

triethylamine; trifluoroacetic anhydride in dichloromethane T=0 - 20°C; 2.08333 h;

<b>Multi-step reaction with 5 steps<br /> </b>1.1: ethanol / 4 h / 85 &deg;C<br />2.1: Dowtherm™ A / 3 h / 250 &deg;C<br />3.1: phosphorus tribromide / N,N-dimethyl-formamide / 1 h / 20 &deg;C<br />4.1: sodium hydroxide / tetrahydrofuran / 0 - 20 &deg;C<br />5.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 0 - 20 &deg;C<br />5.2: 2 h / 0 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: phosphorus tribromide / N,N-dimethyl-formamide / 1 h / 20 &deg;C<br />2.1: sodium hydroxide / tetrahydrofuran / 0 - 20 &deg;C<br />3.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 0 - 20 &deg;C<br />3.2: 2 h / 0 &deg;C<br /> <br /> &nbsp;