3-(N-1-Trityl-imidazol-4-yl)propionic Acid is an intermediate used to prepare imidazole-containing tetrahydrobenzodiazepine inhibitors of farnesyltransferase. It is also used in the synthesis of nonracemic arylpiperazinone analogs of the carboxyl-terminal CAAL sequence of protein geranylgeranyltransferase-I (PGGTase-I) as selective inhibitors of PGGTase-I and of protein farnesyltransferase.