Cycloacylation of chloro-substituted hydroquinone dimethyl ethers with dichloromaleic anhydride

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• 作者：V. L. Novikov ; N. N. Balaneva ; O. P. Shestak ; V. Ph. Anufriev…
• 关键词：chlorohydroquinones ; dichloromaleic anhydride ; cycloacylation ; Zahn—Ochwat reaction ; aromatic electrophilic acylation ; chloronaphthazarins ; disproportionation ; homolysis ; heterolysis ; quantum chemical calculations
• 刊名：Russian Chemical Bulletin
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：65
• 期：4
• 页码：993-1003
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry/Food Science, general; Organic Chemistry; Inorganic Chemistry;
• 出版者：Springer US
• ISSN：1573-9171
• 卷排序：65

文摘

Under the drastic conditions of Zahn—Ochwat cycloacylation of 2-chloroand 2,3-dichlorohydroquinones with dichloromaleic anhydride (a melt of anhydrous AlCl₃ and NaCl, 185—195 °C), the substrates undergo various degrees of disproportionation, which reduces the yields of the target triand tetrachloronaphthazarins. Quantum chemical calculations showed that the cycloacylation in question proceeds as a double aromatic electrophilic substitution of the vicinal protons with the corresponding oxocarbenium ions (acylium cations).