1.1: sulfuric acid / water / 3 h / 160 °C 2.1: thionyl chloride / benzene / 3 h / Reflux 3.1: methanol; sodium tetrahydroborate / tert-butyl alcohol / Reflux 4.1: toluene-4-sulfonic acid / benzene / 2 h / Reflux 5.1: triphenylphosphine; nickel dichloride; zinc / acetonitrile / 0.5 h / 20 °C 5.2: 8 h / Reflux View Scheme

1.1: sulfuric acid / water / 3 h / 160 °C 2.1: thionyl chloride / benzene / 3 h / Reflux 3.1: methanol; sodium tetrahydroborate / tert-butyl alcohol / Reflux 4.1: toluene-4-sulfonic acid / benzene / 2 h / Reflux 5.1: triphenylphosphine; nickel dichloride; zinc / acetonitrile / 0.5 h / 20 °C 5.2: 8 h / Reflux 6.1: sodium hydride / dimethyl sulfoxide; paraffin oil / 0.17 h / 20 °C / Inert atmosphere 6.2: 0.83 h / 40 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1: thionyl chloride / toluene / 20 &deg;C / Reflux<br />2: AlCl₃, aluminium chloride / 0 - 60 &deg;C<br />3: N,N-dimethyl-formamide / 7 h / 110 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: AlCl₃, aluminium chloride / 0 - 60 &deg;C<br />2: N,N-dimethyl-formamide / 7 h / 110 &deg;C<br /> <br /> &nbsp;