The present invention is aimed at providing a whitening agent having an excellent whitening effect. The compound represented by the following general formula (1) or an acid addition salt thereof is used as an effective component of a whitening agent.(In the formula, X represents a C 1-2 alkylene group whose hydrogen atom can be substituted by a methyl group, Y represents COOR 1 or CH 2 OR 2 , and R 1 represents a hydrogen atom or a branched carbon number of 1 to 6 Alkyl group, R 2 represents a hydrogen atom or a branched C 1 to C 6 acetyl group.)本發明係以提供具有優良美白作用的美白劑作為課題。將下述通式(1)所表示之化合物或其酸加成鹽作為美白劑的有效成分。(式中，X表示氫原子可被甲基取代之碳數1~2的伸烷基，Y表示COOR1或CH2OR2，R1表示氫原子或可具有分支之碳數1~6的烷基，R2表示氫原子或可具有分支之碳數1~6的醯基。)
