The present invention relates to: a novel method for preparing a heterocyclic derivative compound of chemical formula I below; a novel intermediate compound used in the preparation method; a composition for treatment or prevention of hyperuricacidemia, gout, nephritis, chronic renal insufficiency, nephrolith, uremia, urolithiasis, or a uric acid-related disease, the composition containing the compound of chemical formula I at a dose of more than 2 mg and equal to or less than 10 mg and being orally administered once a day; and a hydrochloride 1.5 hydrate of the novel compound of chemical formula I.