1: 5-(5-bromo-1H-2-pyridinylidene)-2,2-dimethyl-[1,3]dioxane-4',6-dione With hydrogenchloride; water in 1,4-dioxane T=100°C; 1 h; 2: diazomethyl-trimethyl-silane in methanol; diethyl ether; toluene T=20°C; 0.5 h;

thionyl chloride T=0 - 20°C; 3 h;

thionyl chloride T=20°C; 15 h;

1: 2-(4-biphenylyl)-5-phenyl-oxazole; 2-bromo-cyclopentane-1,3-dione / tetrachloromethane / 15 h / 90 °C / |Inert atmosphere 2: tetrabutylammomium bromide / dichloromethane; water / 15 h / 20 °C 3: thionyl chloride / 15 h / 20 °C View Scheme

1: tetrakis(triphenylphosphine) palladium(0); sodium carbonate / water; toluene / 90 °C / Inert atmosphere 2: methanol; potassium hydroxide / 0 - 20 °C View Scheme