tetrakis(triphenylphosphine) palladium(0); sodium carbonate in 1,4-dioxane; water T=100°C; Suzuki coupling; 24 h; Inert atmosphere;

1,8-diazabicyclo[5.4.0]undec-7-ene; trichlorophosphate in pyridine T=20 - 80°C; Dehydration;

1.1: 90 percent / N-bromosuccinimide / CHCl3 / 3.5 h / Heating 2.1: n-BuLi / diethyl ether; hexane / 0.17 h / -30 °C 2.2: 80 percent / tetrahydrofuran; diethyl ether; hexane / 2 h / 20 °C 3.1: 97 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene; POCl3 / pyridine / 20 - 80 °C View Scheme

1.1: n-BuLi / diethyl ether; hexane / 0.17 h / -30 °C 1.2: 80 percent / tetrahydrofuran; diethyl ether; hexane / 2 h / 20 °C 2.1: 97 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene; POCl3 / pyridine / 20 - 80 °C View Scheme

1.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / -40 °C / |Inert atmosphere 1.2: 1 h / 20 °C / |Inert atmosphere 2.1: ethylene glycol; toluene-4-sulfonic acid / toluene / 5 h / |Reflux; |Dean-Stark View Scheme

Yield given. Multistep reaction;

1: H2 / Pd/C / methanol; tetrahydrofuran / 20 h 2: conc. sulfuric acid / tetrahydrofuran; H2O / 1.5 h View Scheme