Skeletal reactions of perfluoromethylethyl- and perfluorodiethylbenzocyclobutenes with 1,1- and 1,2-alkyl groups in SbF5

Taking perfluoro-1,1-dialkylbenzocyclobutenes as examples, it has been shown to be possible to enlarge the four-membered ring in polyfluorobenzocyclobutenes to five-membered in the presence of SbF₅, by cleavage of the four-membered ring followed by cyclization of the resulting polyfluorostyrene to the polyfluoroindane, which then undergoes further reactions. Perfluoro-1-methyl-1-ethylbenzocyclobutene isomerizes at 50°C in the presence of SbF₅ to perfluoro-,-o -trimethylstyrene, which is reversibly converted at 130°C into perfluoro-1,2-dimethylindane. Perfluoro-l,l-diethylbenzocyclobutene isomerizes at 130°C in the presence of SbF₅ to give perfluoro- -ethyl-,o -dimethylstyrene, which at 170°C gives perfluoro-2-methyl-3-ethylindene- and perfluoro-2-methyl-3-ethyl-4,5,6,7-tetrahydroindene. The last two compounds, together with perfluoro-o-dipropylbenzene, are obtained from per fluoro-1,2-diethylbenzocyclobutene-with SbF₅ at 170°C. From perfluoro-1-methyl-2-ethylbenzocyclobutene with SbF₅ at 95°C there is obtained perfluoro-1-ethylindane, while at 130°C, in addition to the latter compound, there are obtained perfluorinated 1,1-dimethylindane, 1,2-dimethylindane, ,,o-trimethylstyrene, 2,3-dimethylindene, and 2,3-dimethyl-4,5,6,7-tetrahydroindene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1114–1120, May, 1990.     

Isomeric transformations of polyfluorobutenes caused by SbF5

Conclusions The 4-H- and 4-Cl-perfluoro-1-butenes when treated with SbF₅ rearrange to terminal polyfluorobutenes that contain either H or Cl at the multiple bond.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 681–683, March, 1979.     

Splitting of perfluorinated tertiary cyclic amines by the action of SbF5

It was shown that perfluorinated tertiary cyclic amines are dealkylated by the action of SbF₅ with the formation of cyclic azomethines. The presence of a perfluoroalkyl substitutent in the -position to the nitrogen atom in the amine molecule considerably decreases its stability to the action of antimony pentafluoride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1616–1619, July, 1990.     

Skeletal Transformations of the Arylation Products of Perfluoro(1,2-diethylbenzocyclobutene) with Tetrafluorobenzenes in the Presence of SbF5

Russian Journal of Organic Chemistry - The reaction of perfluoro(1,2-diethylbenzocyclobutene) with 1,2,4,5-tetrafluorobenzene in SbF5, followed by hydrolysis, gave products resulting from expansion...     

Reactions of 1,2-dialkyl-3-pyrazolidinones

The condensation of 1,2-dialkyl-3-pyrazoIidinones (1) with a series of aldehydes, ketones and esters in the presence of sodium hydride is described. Alkylation of I with several alkyl bromides gave 4-alkyl substitution products in modest yield and reaction of 1,2,4-trimethyl-3-pyrazolidinone with n-butyl bromide gave a 4,4-dialkylation product. Compound 1 reacted with aryl Grignard reagents to form 3-aryl-3-pyrazoIines whereas the corresponding products were not realized in the case of alkyl Grignards. The reduction of a single example of 1 as well as the reduction of two 3-pyrazolines to pyrazolidines is also reported.     

Synthesis of 1,2-dialkyl-4-pyrazolidinols

Condensation of 1,2-dialkylhydrazines with epichlorohydrin affords 1,2-dialkyl-4-pyrazolidinols in moderate yield.     

Skeletal transformations of perfluorinated 2,2-diethyl- and 2-ethyl-2-phenyl-benzocyclobutenones under the action of antimony pentafluoride

Perfluoro-2-ethyl-2-phenylbenzocyclobutenone heated with SbF₅ at 70 °C and then treated with water, forms perfluoro-3-ethyl-3-phenylphthalide. In contrast to this, heating of perfluoro-2,2-diethylbenzo-cyclobutenone with SbF₅ at 70 °C gives, after treatment of the reaction mixture with water, perfluoro-2-(pent-2-en-3-yl)benzoic acid. When the reaction temperature is raised to 125 °C, a solution of a salt of perfluoro-4-ethyl-3-methylisochromenyl cation is obtained. Hydrolysis of the solution of the salt gives perfluoro-4-ethyl-3-methylisochromen-1-one.     

Synthesis of 1,2-dialkyl-3,6-dimethyl-1,2-dihydropyridazines from acetonylacetone

Condensation of acetonylacetone with symmetrical dimethyl- and diethylhydrazines leads to 1,2-dialkyl-3,6-dimethyl-1,2-dihydropyridazines and 2,3,5,6-tetraalkyl-1,4-dimethyl-2, 3,5,6-tetraazabicyclo[2.2.2]octanes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 400–403, March, 1971.     

Formation of perfluorinated 1,2-dialkylbenzenes from perfluoroalkylbenzocyclobutenes in the system I2-SbF5

Russian Journal of Organic Chemistry -     

Conversion of 2,5-dialkyl-1,3,4-oxadiazoles into 4-substituted 3,5-dialkyl-1,2, 4-triazoles

2, 5-Dialkyl-1, 3, 4-oxadiazoles react on heating with primary amines to form 4-substituted 3, 5-dialkyl-1, 2, 4-triazoles, which is a convenient method for synthesizing these almost unknown compounds.     

Opening of the four-membered ring in perfluorinated 1-alkyl-2-phenyl- and 1-aryl-1,2-dihydrocyclobutabenzenes in the system I<Subscript>2</Subscript>-SbF<Subscript>5</Subscript>

Reactions of perfluorinated 1-phenyl-, 1-(2-ethylphenyl)-, 1-(4-ethylphenyl)-, 1-methyl-2-phenyl-, and 1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzenes with iodine in antimony pentafluoride at 130°C, followed by hydroysis of the reaction mixture, resulted in the formation of perfluorinated 2-methyl-, 2-ethyl-2′-methyl-, 4-ethyl-2′-methyl-, 2-ethyl-, and 2-propylbenzophenones via opening of the four-membered ring in the initial cyclobutabenzene at the C¹–C² bond. The presence of hydrogen fluoride facilitates the process and promotes profound transformations leading to anthracene derivatives.     

Carbonylation of Polyfluorobenzocyclobutenones in a SbF5 Medium

Russian Journal of Organic Chemistry - The carbonylation of perfluoro-2-R-benzocyclobutenones (R = F, CF3, C2F5, C6F5) in a CO-SbF5 system is accompanied by transformations of the four-membered...     

牛奶、母乳中全氟化合物分析方法的研究

建立了HPLC-ESI-MS/MS联用技术测定奶制品中12种全氟化合物(PFCs)的方法.12种全氟化合物包括9种常见PFCs和2种调聚酸及一种全氟磺酰胺.对比了MTBE液-液萃取、甲酸、乙腈和甲醇萃取这4种萃取方法对12种全氟化合物的萃取和回收效果.最终选用甲醇作为萃取溶剂,并选取WAX作为固相萃取柱对萃取的溶液进行净化,方法对12种PFCs的加标回收在83.5%～113.3%之间,检出限0.005～0.092 μg/L.最后完成了对纯牛奶,早餐奶和母乳样品中12种PFCs的分析.     

Themolysis of 3,4-dialkyl-1,2-dioxetames: Effect of cyclic substituents

In 3,4-dialkyl-1,2-dioxetanes, the effect of ring size of cyclic substituents on E_a was found to be 5 ? 7 < 8 < 6 while little or no effect was observed on ΔS^≠.     

New transformations of Si-methoxy-substituted 1,2-disilylethylenes and 1,2-disilylacetylenes

Conclusions Some transformations of 1,2-disilylethylenes and 1,2-disilylacetylenes that involve the methoxyl groups on the silicon atom were described.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2145–2147, September, 1978.     

Isomeric transformations of perfluorinated dienes by the action of antimony pentafluoride

Conclusions It was shown that perfluorinated dienes on being heated with SbF₅, depending on the reaction conditions, form preferentially either perfluoro-1,2-dialkylcyclobutenes or perfluoro-1,2-dialkylcyclopentenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 385–391, February, 1989.The authors wish to express their gratitude to S. S. Bukalov, A. P. Kurbakov, and L. A. Leites for recording and interpreting the Raman spectra.     

Formation of perfluorinated polyphenylenes by multiple pentafluorophenylation using C6F5Si(CH3)3

Pentafluorophenylation of perfluoroarenes with C₆F₅Si(CH₃)₃ was investigated by using NMR and MALDI-TOF-MS techniques. Successive multiple pentafluorophenylation easily occurred not only on the para-position but also on the ortho-positions to provide perfluorinated p-phenylene and m-phenylene compounds. The perfluoroarenes having electron-withdrawing substituents provided oligo- to poly-(phenylene)s depending on the added amounts of C₆F₅Si(CH₃)₃, while the perfluoroarenes having electron-donor substituents gave H(C₆F₄)_nF polymers produced from C₆F₅H, which was the decomposed product of C₆F₅Si(CH₃)₃.