3-Benzo[b]furyl- and 3-benzo[b]thienylaminobutyric acids as GABA(B) ligands. Synthesis and structure-activity relationship studies

Article abstract of DOI:10.1016/0223-5234(96)85165-8

Baclofen (β-p-chlorophenyl GABA) is one of the selective agonists for the bicuculline-insensitive GABA(B) receptors. In the search for new compounds that bind to GABA(B) receptors it is very important to clarify the structural requirements. We report the syntheses of and binding studies on various 3- heteroaromatic (benzo[b]furan and benzo[b]thiophen)aminobutyric acids. The 4- amino-3-(7-methyl-benzo[b]furan-2-yl)butanoic acid 8g is a potent and specific ligand for GABA(B) receptors, with an IC₅₀ value of 5.4 μM in the displacement of [³H]GABA.