We present a convenient synthesis of a chemical library of lactam-fused-β-carbolines via Ugi four-center three-component reaction employing 2-(1-formyl-3-(methoxycarbonyl)-9H-pyrido[3,4- b]indol-9-yl)acetic acid or 2-(1-formyl-9H-pyrido[3,4-b]indol-9-yl)acetic acid, amines and isonitriles.
