(beta-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[b]furan-2-yl)butanoic acid (9h), showed an affinity for the GABAB receptor. The results obtained with racemic compounds of benzofuran structure