Compounds and their pharmaceutical use having a somatostatin receptor agonistic activity

Providing orally administrable low toxicity of the somatostatin receptor subtype 2 agonists. The general formula (I): [Wherein all symbols have the same meanings as defined according to the specification. ] In the compound represented, a salt thereof, N- oxide thereof or a solvate thereof or a prodrug thereof, is administered orally because of the non-peptide low-molecular compound having a potent somatostatin receptor subtype 2 agonist activity, it is possible, also due to low toxicity and are useful in the prevention and / or treatment of somatostatin-related diseases such as acromegaly or gastrointestinal obstruction.