The reaction of dimethylamine with
5-methoxy-1,4-naphthoquinone gives approximately equal amounts of the two
possible substitution products and with 6-methyl-1,4-naphthoquinone followed by
acid hydrolysis 2-hydroxy-6-methyl-l,4-naphtho-quinone is the principal
product. Similar treatment of 5-methyl-1,4-naphthoquinone gives mostly
3-hydroxy-5-methyl-l,4-naphtlioquinone. The isomer, 2-hydroxy-5-
methyl-1,4-naphthoquinone, has been prepared by another method. The product of
Thiele-Winter addition of acetic anhydride to juglone is shown to be a mixture
of the two possible isomers, but authentic 1,3,4,5-tetra-acetoxynaphthalene has
been prepared from 3,5-dihydroxy-1,4-naphthoquinone. The reaction of acetic
anhydride with plumbagin gives three compounds, the composition of the mixture
depending on the time of contact. Juglone and plumbagin have been selectively
brominated in the 6-position and certain other halogen derivatives of these
quinones have been prepared. The preparation of 3-chloro-5-hydroxy-2-methyl-1,4-naphthoquinone
provides a new route by which droserone may be obtained from plumbagin.
二甲胺与
与 5-甲氧基-
1,4-萘醌的反应会产生近似等量的两种可能的取代产物。
与
6-甲基-1,4-萘醌反应,然后进行酸
水解,可生成 2-羟基-
6-甲基-1,4-萘醌。
2-hydroxy-6-methyl-l,4-naphtho-quinone 是主要产物。
产物。对 5-甲基-
1,4-萘醌进行类似处理后,主要产物为
3-羟基-5-甲基-l,4-
萘醌。异构体
2-羟基-5-甲基-1,4-萘醌是主要产物。
甲基-
1,4-萘醌的异构体。其产物为
乙酸酐与
丁二酮的 Thiele-Winter 加成产物被证明是两种可能异构体的混合物。
但真正的 1,3,4,5-四乙酰氧基
萘是由 3,5-
二乙酰氧基
萘制备的。
但真正的 1,3,4,5-四乙酰氧基
萘是由 3,5-二羟基-
1,4-萘醌制备的。
乙酸酐与
反应生成三种化合物,混合物的成分取决于接触的时间。
取决于接触的时间。Juglone 和 plumbagin 在 6 位被选择性
溴化。
6 位
溴化,并制备出了这些
醌类化合物的某些其他卤素衍
生物。
醌的某些其他卤素衍
生物。3-
氯-5-羟基-
2-甲基-1,4-萘醌的制备方法
提供了一条从 plumbagin 中获得 droserone 的新途径。