5069-23-8Relevant academic research and scientific papers
Catalytic transformations of alkylthiophenes
Mashkina,Chernov
, p. 209 - 215 (2007/10/03)
The transformations of alkylthiophenes in the presence of amorphous aluminosilicate and decationated zeolite HNaY were studied. Substituted thiophenes with R = 2- and 3-Me, 2-Et, and 2-iso-Pr undergo dealkylation to thiophene with close rates, migration of the alkyl group from the 9α- to the β-position of the thiophene ring (or in the opposite direction with an elevated rate), and decomposition with H2S elimination. The dealkylation rate of 2-substituted thiophenes with a branched-chain radical (R = iso-Pr, terf-Bu) is much higher and the elimination rate with this radical is lower than those for normal-chain radicals; the isomerization step is virtually absent. Di-, tri-, and tetrasubstituted thiophenes with R = Et and iso-Pr undergo stepwise dealkylation, which is facilitated by an increase in the degree of substitution on the thiophene ring. Thiophene and its lower homologues can be obtained by the transformation of a mixture of high-molecular thiophenes. Copyright
4-?(thien-3-yl)methyl!-imidazole analgesics
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, (2008/06/13)
Described herein are 4-?(thien-3-yl)methyl!-imidazoles of the formula: STR1 wherein R is hydrogen or methyl, and X is C1-4 alkyl, bromine or chlorine; or STR2 wherein Y is hydrogen, C1-4 alkyl, bromine or chlorine, and Z is C1-4
INVESTIGATION OF THE MECHANISM OF THE RECYCLIZATION OF FURANS TO THIOPHENES AND SELENOPHENES UNDER ACID-CATALYSIS CONDITIONS. 3. INVESTIGATION OF THE RECYCLIZATION OF HOMOLOGS AND FUNCTIONAL DERIVATIVES OF FURAN. QUANTUM-CHEMICAL CALCULATIONS OF THE OBJECTS OF THE RECYCLIZATION
Gubina, T. I.,Labunskaya, V. I.,Pankratov, A. N.,Trushin, S. A.,Kharchenko, V. G.
, p. 1393 - 1398 (2007/10/02)
The kinetics of the conversion of di-, tri-, and tetraalkylfurans to the corresponding thiophenes were investigated.A correlation between the reactivities and structures of the investigated furans was established.Quantum-chemical calculations of the objects of the recyclization were made.The calculated and experimental data on the reactivities of the investigated compounds were compared.The most likely pathway of the protonation of furans in their recyclization was determined on the basis of calculations of the total energies of the protonated forms.
An Electron Spin Resonance Study of the Radical Cations of Pyrroles, Furans, and Thiophenes in Liquid Solution
Davies, Alwyn G.,Julia, Luis,Yazdi, Safieh N.
, p. 239 - 244 (2007/10/02)
Photolysis of alkylpyrroles in trifluoroacetic acid containing mercury(II) trifluoroacetate, alkylfurans in trifluoroacetic acid, or alkylthiophenes in sulphuric acid, induces oxidation to the corresponding radical cations.The e.s.r. spectra show that the electronic configuration is similar in all three species, the unpaired electron occupying the φA MO in which the heteroatom lies in a nodal plane.Photolysis of 2,6-dimethyl- and 2,6-diethyl-thiophene in trifluoroacetic acid containing mercury(II) trifluoroacetate, on the other hand, gave rise to spectra with a high g value (2.0062), showing hyperfine coupling to two non-equivalent pairs of alkyl groups in an unsymmetrical dimer.
