1: (i) Zn, I2, (ii) HCO2H, (iii) aq. KOH 2: (i) PCl5, (ii) SnCl4 3: KOH, N2H4*H2O / ethane-1,2-diol / 160 - 200 °C 4: Se / 300 - 320 °C View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1.1: AlCl₃, aluminium chloride / carbon disulfide / 4.75 h / 20 &deg;C / Inert atmosphere<br />1.2: 0.67 h / 90 &deg;C<br />2.1: palladium diacetate; sodium t-butanolate; 2-(dicyclohexylphosphino)-2',4',6'-tri-i-propyl-1,1’-biphenyl / toluene / Inert atmosphere; Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1.1: n-butyllithium; diisopropylamine / tetrahydrofuran; hexane / 1 h / -60 &deg;C<br />1.2: 20 &deg;C<br />2.1: water; potassium hydroxide / ethanol; water / 3 h / Reflux<br />3.1: thionyl chloride; N,N-dimethyl-formamide / dichloromethane / 1 h / Reflux<br />4.1: AlCl₃, aluminium chloride / dichloromethane / 0.5 h / 0 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1.1: n-butyllithium; diisopropylamine / tetrahydrofuran; hexane / 1 h / -60 &deg;C<br />1.2: 20 &deg;C<br />2.1: water; potassium hydroxide / ethanol; water / 3 h / Reflux<br />3.1: thionyl chloride; N,N-dimethyl-formamide / dichloromethane / 1 h / Reflux<br />4.1: AlCl₃, aluminium chloride / dichloromethane / 0.5 h / 0 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: Ac₂O, Et₃N<br />2: Na-Hg, aq. NaOH<br />3: (i) SOCl₂, (ii) AlCl₃ <br /> <br /> &nbsp;