A series of phenethanolamines (3) based on salicylamide has been prepared and shown to possess beta-adrenergic blocking properties. When the basic nitrogen atom was substituted by some aralkyl groups, the compounds also blocked alpha-adrenoceptors. The 1-methyl-3-phenylpropyl derivative labetalol (34) is antihypertensive in animals and man, and syntheses of its four stereoisomers are described. The enantiomer 90 with the R configuration at both asymmetric centers possessed most of the beta-blocking activity but little alpha-blocking activity. That with the S configuration at the alcoholic carbon and the R configuration on the amino substituent, 89, is predominantly an alpha-adrenoceptor blocking agent.

Eine Reihe von Phenethanolaminen (II) auf der Basis von Salicylamid werden auf verschiedenen Wegen ausgehend von Estern (I) oder (III), aus Bromacetophenonen (IV) oder aus Ethanolaminen (VII) hergestellt.

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