Sulfonylureas stimulate insulin secretion independent of the blood glucose concentration and therefore cause hypoglycemia in type 2 diabetic patients. Over the last years, a number of aryl-imidazoline derivatives have been identified that stimulate insulin secretion in a glucose-dependent manner. In the present study, we have developed three series of substituted N-(thieno [2, 3-b] pyridin-3-yl)-guanidine (2a–l), N-(1H-pyrrolo [2, 3-b] pyridin-3 ...