1.1: acetic acid 1.2: 0.5 h / 20 °C 2.1: sodium hydrogencarbonate / water; dichloromethane / pH > 7.5 3.1: pyridine / dichloromethane / 0.08 h 3.2: 0.08 h 4.1: caesium carbonate; bis(dibenzylideneacetone)-palladium(0); di-tert-butyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine / 1,4-dioxane / 24 h / |Reflux View Scheme