G. Abbenante et al., POTENTIAL GABA-B RECEPTOR ANTAGONISTS .9. THE SYNTHESIS OF 3-AMINO-3-(4-CHLOROPHENYL) PROPANOIC ACID, 2-AMINO-2-(4-CHLOROPHENYL)ETHYLPHOSPHONIC ACID AND 2-AMINO-2-(4-CHLOROPHENYL)ETHANESULFONIC ACID, Australian Journal of Chemistry, 50(6), 1997, pp. 523-527
This paper describes the synthesis of 3-amino-3-(4-chlorophenyl)propan
oic acid and the corresponding phosphonic and sulfonic acids, lower ho
mologues of baclofen, phaclofen and saclofen respectively. The chlorin
ated acids were all weak specific antagonists of GABA at the GABAB rec
eptor, with the sulfonic acid (pA(2) 4.0) being stronger than the phos
phonic acid (pA(2) 3.8) and carboxylic acid (pA(2) 3.5).