PROBLEM TO BE SOLVED: To provide a compound having a high skin whitening effect and excellent safety and stability, and an external preparation for skin with which this compound is blended.SOLUTION: The compound is a 4-alkylresorcinol derivative represented by general formula (1) or a salt thereof (in formula, R1 is a branched or cyclic 3-7C alkyl group or a straight chain 2-5C alkyl group, R2 and R3 are each independently a hydrogen atom or a group represented by -P(O)(OR4)(OR5) and at least one of R2 and R3 is a group represented by -P(O)(OR4)(OR5), and R4 and R5 are each independently a hydrogen atom or a straight chain or branched 2-5C alkyl group).COPYRIGHT: (C)2012,JPO&INPIT【課題】高い美白効果を有し、安全性や安定性にも優れる化合物、ならびにこれを配合した皮膚外用剤を提供する。【解決手段】下記一般式(1)で示される4-アルキルレゾルシノール誘導体又はその塩。(式中、R1は分岐又は環状の炭素数3~7のアルキル基、あるいは直鎖の炭素数2~5のアルキル基;R2及びR3はそれぞれ独立して水素原子又は-P(O)(OR4)(OR5)で示される基で、R2及びR3の一方あるいは両方が-P(O)(OR4)(OR5)で示される基;R4及びR5はそれぞれ独立して水素原子あるいは直鎖又は分岐の炭素数2~5のアルキル基。)【選択図】なし
