1.1: potassium carbonate / triphenyl-arsane; tris-(dibenzylideneacetone)dipalladium(0) / N,N-dimethyl-formamide / 2 h / 60 - 65 °C / Inert atmosphere 2.1: N-ethyl-N,N-diisopropylamine / dichloromethane / 0.5 h / 20 - 35 °C / Inert atmosphere 2.2: 2 h / 20 - 25 °C 3.1: toluene-4-sulfonic acid / methanol / 1 h / 25 °C 4.1: trichlorophosphate / toluene / 0.17 h / 20 °C / Inert atmosphere 4.2: 3 h / 30 - 75 °C 5.1: isopropyl alcohol / 4 h / 70 °C / Inert atmosphere 6.1: sodium hydroxide / ethyl acetate; water / pH ~ 10 / Inert atmosphere 6.2: 1 h / 40 °C View Scheme