1: tert-butyl 3-ethynylbenzoate With trifluoroacetic acid in dichloromethane T=20°C; 3 h; 2: methanol With sulfuric acid T=65°C; 20 h;

methanol; potassium carbonate T=20°C; 0.0833333 h;

sodium hydride in toluene T=110°C;

1: (Ph3P)3CuBr; (Ph3P)2PdCl2; Et3N / 18 h / Heating 2: 421 mg / NaH / toluene / Heating View Scheme

1: 98 percent / Pd(PPh3)4; CuI / triethylamine; dimethylformamide / 16 h / 40 °C 2: 76 percent / K2CO3 / methanol / 2 h / 20 °C View Scheme

1.1: 4-(N,N-dimethlyamino)pyridine / dichloromethane / 64 h / 20 °C / Inert atmosphere 2.1: triethylamine / tetrakis(triphenylphosphine) palladium(0); copper(l) iodide / tetrahydrofuran / 0.17 h / Inert atmosphere 2.2: 18 h 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 17 h / 0 - 20 °C / Inert atmosphere 4.1: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 4.2: 20 h / 65 °C View Scheme

1.1: triethylamine / tetrakis(triphenylphosphine) palladium(0); copper(l) iodide / tetrahydrofuran / 0.17 h / Inert atmosphere 1.2: 18 h 2.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 17 h / 0 - 20 °C / Inert atmosphere 3.1: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 3.2: 20 h / 65 °C View Scheme

1.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 17 h / 0 - 20 °C / Inert atmosphere 2.1: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 2.2: 20 h / 65 °C View Scheme

in toluene T=75°C; 6 h; Title compound not separated from byproducts;

lithium aluminium tetrahydride in tetrahydrofuran