PROBLEM TO BE SOLVED: To provide an inhibitor of cytochrome p450 monooxygenase, and an intermediate involved.SOLUTION: This invention provides a compound of formula IV that is an intermediate of a urea derivative that is an inhibitor of cytochrome p450 monooxygenase, or salt thereof, or the like. In the formula, Rand Rindependently represent proper protective groups.【課題】チトクロームP450モノオキシゲナーゼの阻害剤及びそれに関わる中間体の提供。【解決手段】チトクロームP450モノオキシゲナーゼの阻害剤である尿素誘導体の中間体である式IVの化合物またはその塩、等。(式中、R1及びR2はそれぞれ独立して適切な保護基である)【選択図】なし