Provided is a pyridine derivative represented by formula (I), a prodrug thereof, a pharmaceutically acceptable salt of the pyridine derivative or the prodrug, or a solvate of the pyridine derivative, the prodrug or the pharmaceutically acceptable salt, which is useful for treatment or prophylaxis of diseases associated with URAT1 such as gout, hyperuricemia, hypertension, kidney diseases such as interstitial nephritis, diabetes, arteriosclerosis and Lesch-Nyhan syndrome.