1-substituted 2-benzylaminobenzimidazole derivatives: compounds with H 1-antihistaminic activity

Abstract

The preparation of 1-substituted 2-benzylaminobenzimidazole derivatives 13–24 is described. Although these compounds have a different structure from the general structure I of antihistamines, they showed some antihistaminic activity (pA 2: 5–7) when tested in vitro on guinea pig ileum. The introduction of an additional basic centre as in the Mannich bases 25–27 did not cause any improvement of activity. All the compounds tested proved to be inactive in in vivo induced passive cutaneous anaphylaxis (PCA) and cutaneous vasopermeability in rats.