Studies on benzenesulfonamide derivatives with alpha- and beta-adrenergic antagonistic and antihypertensive activities.

Abstract

New α-and β-adrenergic blockers, benzenesulfonamide derivatives (Ia-z), were prepared from acetylbenzenesulfonamides (II) by two methods. These compounds were tested for α-and β-blocking activities and their structure-activity relationships are discussed. All the target compounds have two asymmetric centers and therefore consist of two diastereomers. 5-[1-Hydroxy-2-[3-(2-methoxyphenyl)-1-methylpropylamino]ethyl]-2-methylbenzenesulfonamide (Ir) and 5-[1-hydroxy-2-[2-2-(2-methoxyphenoxy)-1-methylethylamino] ethyl]-2-methylbenzenesulfonamide (Iu) showed potent α-and β-blocking activities and they were each separated into two diastereomers (Ir-A and Ir-B, and Iu-A and Iu-B). It was found that one isomer had mainly β-blocking activity and the other isomer had mainly α-blocking activity. In addition, several compounds showing relatively strong α-and β-blocking activities were also examined for antihypertensive activity in conscious spontaneously hypertensive rats. Among the compounds tested, Ir and Iu were the most active, and they were more potent than labetalol. Compounds Ir and Iu may be of practical use as potent antihypertensive agents.