P-2-Thienylalanine3s4t5 and P-2-furylalanine6 have been shown to inhibit microbial growth, presumably due to their structural similarity to phenylalanine. The corresponding nitrogen analog,/3-2-pyrrolealanine, is not described in the literature. As part of a program to correlate the structure of amino acids with their biological activity, it seemed desirable to prepare this substance so that it might be available for microbiological study.