Baclofen (0-p-chlorophenyl-GABA) is the only selective agonist for the bicuculline- insensitive GABAB receptor. We report the synthesis of new GABA analogues and baclofen analogues. In vitro, two compounds, 4-amino-3-benzo [b] furan-2-ylbutanoic acid (9g) and 4- amino-3-(5-methoxybenzo [blfuran-2-y1) butanoic acid (9h), showed an affinity for the GABAB receptor. The results obtained with racemic compounds of benzofuran structure, ...