Synthesis of [3–12′,4′,5′‐triethoxybenzoyl‐(carbonyl‐ 14 C)] propionic acid (AA‐149‐ 14 C)

The synthesis of 3‐[ 2′,4′,5′‐triethoxybenzoyl‐(carbonyl‐ 14 C)]‐propionic acid (VII) is described. Chloroacetonitrile‐ 14 C (IV) was prepared from chloroacetic‐1‐ 14 C acid (I) according to the well‐known procedure. IV was reacted with 1,2,4‐triethoxybenzene in the presence of ZnCl 2 and HCl, and the resulting ketoimine hydrochloride was hydrolyzed to 2′,4′,5′‐triethoxyphenacyl‐(carbonyl‐ 14 C) chloride (V) in 66.5% yield. VII was obtained in 66% from ethyl [2′,4′,5′‐triethoxyphenacyl‐(carbonyl‐ 14 C)] malonate (VI) which had been prepared in 57% from V by an application of malonic ester synthesis. The overall radiochemical yield from I to VII was 11.2%.