共查询到20条相似文献,搜索用时 15 毫秒
1.
A. N. Perevoshchikova A. A. Gorbunov Yu. S. Rozhkova P. A. Slepukhin Yu. V. Shklyaev 《Russian Journal of Organic Chemistry》2014,50(4):513-517
The reaction of 1-(4-methoxyphenyl)-1-(1-methylcyclohexyl)ethanol with nitriles in concentrated sulfuric acid afforded 1′-substituted 6′-methoxy-4′,4′-dimethyl-4′H-spiro[cyclohexane-1,3′-isoquinolines] as a result of consecutive Wagner-Meerwein rearrangement and Ritter reaction. 相似文献
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The title compounds, 4'-0-geranylisoliquiritigenin and 4'-0-geranylnaringenin isolated from Millettia ferruginea and Borania coerulescens respectively, were first synthesized starting from geranyl bromide, 4-hydroxybenzaldehyde and O-hydroxy acetophenones by the condensation reaction and demethoxymethylation as key steps. 相似文献
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T. P. Glushenko V. I. Goncharov A. V. Aksenov 《Chemistry of Heterocyclic Compounds》2008,44(3):314-315
A method has been developed for the synthesis of 1′-R-1′,4′-dihydro-2,3′-biquinolin-4′-ones based on the interaction of quinaldine
with N-alkyl-N-formylanthranilic acid methyl esters under the conditions of the Claisen condensation.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 409–410, March 2008. 相似文献
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A convenient and high yield preparation of 4, 4′-dicarboxy-2, 2′-bipyridine from the oxidation 4, 4′-dimethyl-2, 2′-bipyridine with potassium dichromate in sulfuric acid is reported. 相似文献
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Values of the condensed phase standard (p = 0.1 MPa) molar enthalpy of formation for 2′- and 4′-methylacetophenones were derived from the standard molar energies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The values of the standard molar enthalpy of vaporization, at T = 298.15 K, were measured by Calvet microcalorimetry. Combining these two values, the following enthalpies of formation in the gas phase, at T = 298.15 K, were then derived: 2′-methylacetophenone, –(115.7 ± 2.4) kJ · mol−1, and 4′-methylacetophenone, –(122.6 ± 2.4) kJ · mol−1. Substituent effects are discussed in terms of stability and compared with other similar compounds. The value of the standard molar enthalpy of formation for 3′-methylacetophenone was estimated from isomerization schemes. 相似文献
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P. A. Slepukhin N. S. Boltacheva V. I. Filyakova V. N. Charushin 《Journal of Structural Chemistry》2011,52(2):443-444
Specific features of the molecular and crystal structures of 1,5-bis-(4′,4′,4′-trifluoro-1′-methyl-3′-oxo-but-1′-enylamino)-3-oxapentane are determined by single crystal XRD. 相似文献
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《Tetrahedron: Asymmetry》2001,12(7):1015-1023
1,3-Dioxolanone alcohols, prepared via the addition of chiral lithium enolates of 1,3-dioxolan-4-ones to aldehydes, are suitable intermediates for the synthesis of chiral trisubstituted isoserines or trisubstituted 3-hydroxy-β-lactams. In particular, the methyl ester of 2-methyl-3-(2-furyl)isoserinic acid and two 3-methyl-3-hydroxy-β-lactams bearing either a 2-furyl or a phenyl substituent at C-(4) have been prepared. The (2R,3S) stereochemistry of the isoserine, and the (3R,4S) stereochemistry of the two β-lactams is that required for the synthesis of taxoid analogues having the side-chain with the proper (2′R,3′S) configuration. 相似文献
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The crystal structure of the title compound(C24H24N2O5, Mr = 420.45) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1 with a = 8.991(1), b = 11.166(1), c = 11.169(1) , α = 91.413(2), β = 105.887(2), γ = 90.992(2)°, V = 1077.8(2) 3, Z = 2, Dc = 1.296 g/cm3, F(000) = 444, μ(MoKα) = 0.091 mm-1, the final R = 0.0466 and wR = 0.1507 for 4185 observed reflections(I 2σ(I)). The single-crystal X-ray diffraction data indicated intermolecular C(17)–H(17)O(4), C(5)–H(5)… O(4) hydrogen bonds and C–H…π interaction in the structure. 相似文献
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I. Victor Ekhato 《合成通讯》2013,43(16):2341-2349
(4′R)- and (4′S)-Spiro(oxirane-2,4′-5α-cholestan-3′β-ol) (1) and (2) were made from (4′R)- and (4′S)-spiro(oxirane-2,4′-5α-cholestan-3-one) (8) and (9). Alkaline hydrogen peroxide oxidation of 4-methylene-5α-cholestan-3-one (7) gave compounds (8) and (9) as a readily separable (1:1) mixture. Reduction of (9) to (2) provided access to a compound which could not be made by other methods. 相似文献
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P. Mačkus P. N. Kovalskij K. Lipskis A. Martinaitis 《Colloid and polymer science》1992,270(3):243-248
In 4-nitro-4-aminodiphenyl (NAD) layers the photocapacitance (PhC) transients were investigated. PhC spectral distribution as well as the temperature dependences of time constants (under/on/or after/off/illumination) have been measured. The photocapacitance spectral distribution possesses maxima at 350, 500, and 750 nm. It was shown that on (T) is of exponential form while off (T) is more complicated. The values of thermal activation energies (0.65±0.05) eV of both time constants coincide. The mechanism of photocapacitance process has been disclosed in NAD layers. 相似文献
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In situ observation of the optical texture, and X-ray patterns of the pressure-induced mesophase seen for 4′-n-hexadecyloxy-3′-nitrobiphenyl-4-carboxylic acid (ANBC-16) was performed under hydrostatic pressures up to 100MPa using a polarizing optical microscope equipped with a high pressure hot stage and a wide angle X-ray diffractometer equipped with a high pressure vessel respectively. It was found that the pressure-induced mesophase (hereafter refered to as ‘X’) appeared at pressures above 60 MPa, and exhibits a birefringent broken-fan or a sand-like texture that remain unaltered in the SmC phase. The POM-transmitted light intensity curve measured on heating clearly showed the Cr4 → Cr1 → SmC → ‘X’ → SmA → I transition sequence at 80 MPa. The optical texture and the POM-transmitted light intensity measured during a pressure cycle at 185°C showed a reversible change between the cubic and ‘X’ phases. The WAXD pattern of the ‘X’ phase showed a spot-like pattern, suggesting no layered structure for this phase, and also revealed a substantial decrease in the d-spacing of the low angle reflection at 80 and 100 MPa, compared with the d-spacings of the (0 0 1) reflection of the SmC phase and also the (2 1 1) reflection of the cubic phase. It is concluded from these data that the ‘X’ phase is a birefringent hexagonal columnar phase. 相似文献
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M. Karakaya F. Ucun 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(7):1147-1157
The goal of this study is to determine the most stable tautomeric forms, and their ground state conformers of 4′-nitroazobenzene-2,4-diol and 4-methyl-4′-nitroazobenzene-2,6-diol compounds. The calculations have shown that the most stable tautomeric forms of the compounds are hydrazo form for 4′-nitroazobenzene-2,4-diol and azo form for 4-methyl-4′-nitroazobenzene-2,6-diol. Besides, the vibrational frequencies, 1H and 13C NMR shifts, frontier molecular orbital’s energies for the tautomeric forms of the compounds calculated by using density functional theory-B3LYP method with 6-311G(d) basis set were interpreted. All the assignments of the theoretical frequencies were identified by potential energy distribution (PED) analysis. Generally, theoretical spectral results were seen to be in a good agreement with the corresponding experimental data. 相似文献
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A facile procedure for the synthesis of 3-(2′-amino-3′-cyano-4′-arylpyrid-6′-yl)coumarins are being reported starting from 3- acetylcoumarin,aromatic aldehydes and malononitrile.The reactions were carded out on microwave irradiation in good yield with short time and easy work-up.The structures of all the compounds have been confirmed on the basis of their analytical,IR,~1H NMR, and mass spectral data. 相似文献
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《Microchemical Journal》1987,36(2):172-181
N,N-Dimethyl-4-amino-4′-aminoazobenzene has been determined using differential pulse polarography. Fast-scan modification and linear-scan voltammetry at a hanging mercury drop electrode was used with a detection limit of less than 10−8 mol liter−1. Differential pulse polarography was then used to analyze mixtures of the above depolarizer with azobenzene and N,N-dimethyl-4-aminoazobenzene, either directly, or after a TLC separation. 相似文献