1. 3¿ is aryl which may have suitable substituent(s), and A is lower alkylene, or a pharmaceutically acceptable salt thereof, for the treatment of various diseases selected from the group consisting of cardiac hypertrophy, nephropacy such as nephritis or renal failure, arteriosclerosis, obliterans, obstructive thrombus, arterial embolus, Bürger-Grütz syndrome, acrocyanosis, chilblain, frostbite, prolactin-producing ovulation disorder, prolactin-producing pituitary tumor, puerperal galactoschesia, galactorrhea, distal hypertrophy, pituitary gigantism, mental illness, cerebrovascular diseases, tachycardia accompanied by sympathetic hypertonia, hyperaldosteronism, and diabetic complication.

3¿ représente aryle ou éventuellement son ou ses substituants appropriés, et A représente alkylène inférieur.