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|Section2= |Section3= }} Naphthazarin, often called 5,8-dihydroxy-1,4-naphthoquinone or 5,8-dihydroxy-1,4-naphthalenedione (IUPAC), is a naturally occurring〔 Thomson R.H. Naturally Occurring Quinones. Academic Press, London (1971). Quoted by Khalafy and Bruce. 〕〔 Thomson R.H. Naturally Occurring Quinones III. Chapman and Hall, London (1987). Quoted by Khalafy and Bruce. 〕 organic compound with formula , formally derived from 1,4-naphthoquinone through replacement of two hydrogen atoms by hydroxyl (OH) groups. It is thus one of many dihydroxynaphthoquinone structural isomers. Naphthazarin is soluble in 1,4-dioxane from which it crystallizes as deep red needles that melt at 228−232 °C.〔 == Synthesis == Naphtharazin can be prepared by condensation of 1,4-dimethoxybenzene with 2,3-dichloromaleic anhydride followed by reductive dechlorination and reoxidation.〔 Lewis J.R. and Paul J.J.(1977). Z. Naturforsch., B, 32: 1473. Quoted by Khalafy and Bruce. 〕〔 Huot R. and Brassard P. (1974). Can. J. Chem., 52: 838. Quoted by Khalafy and Bruce. 〕 Naphtharazin can also be obtained by oxidation of 5,8-dihydroxy-1-tetralone with manganese dioxide (MnO2).〔 J. Khalafy and J.M. Bruce (2002), ''Oxidative dehydrogenation of 1-tetralones: Synthesis of juglone, naphthazarin, and α-hydroxyanthraquinones''. Journal of Sciences, Islamic Republic of Iran, volume 13 issue 2, pages 131-139. 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「5,8-Dihydroxy-1,4-naphthoquinone」の詳細全文を読む スポンサード リンク
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