Synthesis and Pharmacological Evaluation of Novel γ-Aminobutyric Acid Type B (GABAB) Receptor Agonists as Gastroesophageal Reflux Inhibitors
摘要:
We have previously demonstrated that the prototypical GABA(B) receptor agonist baclofen inhibits transient lower esophageal sphincter relaxations (TLESRs), the most important mechanism for gastroesophageal reflux. Thus, GABAB agonists could be exploited for the treatment of gastroesophageal reflux disease. However, baclofen, which is used as an antispastic agent, and other previously known GABAB agonists can produce CNS side effects such as sedation, dizziness, nausea, and vomiting at higher doses. We now report the discovery of atypical GABAB agonists devoid of classical GABAB agonist related CNS side effects at therapeutic doses and the optimization of this type of compound for inhibition of TLESRs, which has resulted in a candidate drug (R)-7 (AZD3355) that is presently being evaluated in man.
Synthesis and Pharmacological Evaluation of Novel γ-Aminobutyric Acid Type B (GABAB) Receptor Agonists as Gastroesophageal Reflux Inhibitors
摘要:
We have previously demonstrated that the prototypical GABA(B) receptor agonist baclofen inhibits transient lower esophageal sphincter relaxations (TLESRs), the most important mechanism for gastroesophageal reflux. Thus, GABAB agonists could be exploited for the treatment of gastroesophageal reflux disease. However, baclofen, which is used as an antispastic agent, and other previously known GABAB agonists can produce CNS side effects such as sedation, dizziness, nausea, and vomiting at higher doses. We now report the discovery of atypical GABAB agonists devoid of classical GABAB agonist related CNS side effects at therapeutic doses and the optimization of this type of compound for inhibition of TLESRs, which has resulted in a candidate drug (R)-7 (AZD3355) that is presently being evaluated in man.
Early scale-up work of a promising reflux inhibitor AZD6906 is described. Two steps of an earlier route were adapted to be performed in continuous flow to avoid issues related to batch procedures, resulting in a robust method with reduced cost of goods and improved product quality. Toxic and reactive reagents and starting materials could be handled in a flow regime, thereby allowing safer and more convenient reaction optimization and production.