- Infrared and Raman spectra, conformational stability, ab initio calculations and vibrational assignments for trans-3-chloropropenoyl chloride.
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The infrared (3500-30 cm(-1)) spectra of gaseous and solid and the Raman (3500-200 cm(-1)) spectra of the liquid with quantitative depolarization ratios and solid trans-3-chloropropenoyl chloride (trans-ClCHCHCClO) have been recorded. These data indicate that both the anti (carbonyl bond trans to the carbon-carbon double bond) and syn conformers are present in the fluid states but only the anti conformer is present in the crystalline state. The mid-infrared spectra of the sample dissolved in liquid xenon as a function of temperature (-55 to -100 degrees C) have been recorded. Utilizing conformer pairs at 870 and 725 cm(-1), 1215 and 1029 cm(-1), and 1215 and 1228 cm(-1), the enthalpy difference has been determined to be 136+/-5 cm(-1) (389+/-14 cal mol(-1)) with the anti conformer the more stable form. Optimized geometries and conformational stabilities were obtained from ab initio calculations at the levels of RHF/6-31G(d), MP2/6-31G(d), MP2/6-311 + + G(d,p), MP2/6-311 + + G(2d,2p) and MP2/6-311 + + G(2df,2pd) with only the latter two calculations predicting the anti rotamer to be the more stable form. The vibrational frequencies, harmonic force constants and infrared intensities were obtained from the MP2/6-31G(d) calculations, whereas the Raman activities and depolarization values were obtained from the RHF/6-31G(d) calculations. The spectra are interpreted in detail and the results are compared with those obtained for some related molecules.
- Durig,Drew,Reese,Brletic
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- N-Vinyl and N-Aryl Hydroxypyridinium Ions: Charge-Activated Catalysts with Electron-Withdrawing Groups
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Charge-enhanced Br?nsted acid organocatalysts with electron-withdrawing substituents were synthesized, and their relative acidities were characterized by computations, 1:1 binding equilibrium constants (K1:1) with a UV-vis active sensor, 31P NMR shifts upon coordination with triethylphosphine oxide, and in one case by infrared spectroscopy. Pseudo-first-order rate constants were determined for the Friedel-Crafts alkylations of N-methylindole with trans-β-nitrostyrene and 2,2,2-trifluoroacetophenone and the Diels-Alder reaction of cyclopentadiene with methyl vinyl ketone. These results along with kinetic isotope effect determinations revealed that the rate-determining step in the Friedel-Crafts transformations can shift from carbon-carbon bond formation to proton transfer to the catalyst's conjugate base. This leads to an inverted parabolic reaction rate profile and slower reactions with more acidic catalysts in some cases. Electron-withdrawing groups placed on the N-vinyl and N-aryl substituents of hydroxypyridinium ion salts lead to enhanced acidities, more acidic catalysts than trifluoroacetic acid, and a linear correlation between the logarithms of the Diels-Alder rate constants and measured K1:1 values.
- Riegel, George F.,Kass, Steven R.
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p. 6017 - 6026
(2020/05/26)
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- QUINAZOLINE DERIVATIVE, PREPARATION METHOD THEREFOR, AND PHARMACEUTICAL COMPOSITION AND APPLICATION THEREOF
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Disclosed are a quinazoline derivative, a preparation method therefor, and a pharmaceutical composition and an application thereof. The present invention provides a compound represented by general formula I, a stereoisomer thereof and a pharmaceutical acceptable salt or a solvate thereof. The quinazoline derivative of the present invention has a unique chemical structure, is characterized by irreversibly inhibiting EGFR tyrosine kinase, has high biological activity, apparently improves the inhibiting effect on the EGFR tyrosine kinase, has quite strong tumor inhibiting effect on tumor cells and a transplantation tumor pathological model of animal tumors, and has good market developing prospects.
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Paragraph 0278; 0279
(2017/07/14)
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- Hydrochlorination of 2,3-acetylenic acids with thionyl chloride in dimethylformamide
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The reaction of 2,3-acetylenic acids (1a-d) with thionyl chloride in DMF under mild conditions gave E,Z-3-chloro-2-alkenoic acids (2a-d) or esters (3a-d) depending on treating the reaction mixture with either water or alcohols.
- Urdaneta, Neudo A.,Herrera, Julio C.,Salazar, Jose,Lopez, Simon E.
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p. 3003 - 3009
(2007/10/03)
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- Chromium(II) Reduction of Trichloromethyl Carbinols and their Corresponding Ethers: One-step Synthesis of Z-Vinyl Chlorides
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Secondary trichloromethyl carbinols and their corresponding ethers can be reduced by chemically or electrochemically generated chromium(II) chloride to form Z-monochlorovinyl compounds in one step.In the presence of a carboxy function in the α-position an E-double bond is formed.Tertiary cabinols favour the formation of dichlorovinyl compounds and rearranged carbonyl compounds.Product ratios can be altered drastically by a change in the reaction conditions; this sheds light on the reaction mechanism.
- Wolf, Reinhard,Steckhan, Eberhard
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p. 733 - 740
(2007/10/02)
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