- 1,2-butene and second hydrogen cyclo [α] naphtalenes new synthetic method
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The invention discloses a novel synthetic method of 1,2-dihydro cyclobutene [alpha] naphthalene, which comprises the following steps that (1) 2-methylnaphthalene, paraformaldehyde, glacial acetic acid and hydrochloric acid are directly fed; heating and reaction are performed at 60-70 DEG C; a 1-chloromethane-2-methylnaphthalene crude product is prepared; (2) the obtained 1-chloromethane-2-methylnaphthalene crude product is subjected to reduced pressure distillation; unconverted 2-methylnaphthalene is removed; high-purity 1-chloromethane-2-methylnaphthalene is obtained; (3) high-purity 1-chloromethane-2-methylnaphthalene is added to a pyrolyzer for pyrolysis; a 1,2-dihydro cyclobutene [alpha] naphthalene crude product is obtained; and (4) the 1,2-dihydro cyclobutene [alpha] naphthalene crude product is dried, distilled, subjected to column chromatography and condensed; and a target product is obtained. Compared with the prior art, the method takes 2-methylnaphthalene as a basic raw material to prepare 1,2-dihydro cyclobutene [alpha] naphthalene by chloromethylation and pyrolysis cyclization, and is mild in synthetic condition, high in yield, very high in production value and good in industrial prospect.
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Paragraph 0054-0056
(2017/03/08)
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- Aromatization of 1,4-Dihydrobenzocycloalkenes, 1,4-Dihydronaphthocycloalkenes, and Related Systems
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A series of methyl-substituted 1,4-dihydrobenzenes has been prepared, and the rates of oxidation of these molecules by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) have been measured.Existing evidence points to the involvement of a positively charged intermediate which is formed as an ion pair in an initial rate-limiting hydride transfer to DDQ.Series of cycloalkyl-fused 1,4-dihydrobenzenes and 1,4-dihydronaphthalines (fused 1,2 and 2,3) have been prepared and the rates of their DDQ induced aromatization have been studied.The results are explained on the basis of inductive effects associated with the size of the fused ringand exocyclic vs. endocyclic bond order preferences.
- Thummel, Randolph P.,Cravey, Wesley E.,Cantu, David B.
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p. 1633 - 1637
(2007/10/02)
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