AbstractDiethyl acetamidomalonate‐2‐14C was alkylated by l‐chloromethylpyrazole and the reaction intermediate hydrolyzed to give DL‐3‐(1′‐pyrazolyl)‐alanine‐2‐14C. By the same method, but using 3‐chloromethylpyrazole instead of the 1‐isomer, DL‐3‐(3′‐pyrazolyl)‐alanine‐2‐14C was prepared. Condensation of furfural with hydantoin‐5‐14C gave 5‐(2′‐furylidene)‐hydantoin‐5‐14C, which was subsequently reduced to 5‐(2′‐furyl)‐hydantoin‐5‐14C and this compound was hydrolyzed to DL‐3‐(2′‐furyl)‐alanine‐2‐14C. Methods f