Photochemistry of 2-(Perfluoroalkyl)cycloalkanones

In an earlier study [1] we had compared the photochemical behaviour of 2-trifluoromethylcyclohexanone ( ) to that of the non-fluorinated parent ketone 2-methylcyclohexanone. Substitution of the methyl group on C(2) by a CF₃-group strongly enhances bimolecular reactions such as reduction product formation in 2-propanol or oxetane formation in the presence of alkenes. We now report preliminary results on monomolecular photochemical reactions of several 2-(perfluoroalkyl)cycloalkanones.     

Microwave Spectrum and Structure of 2-(Trifluoromethyl)pyridine

The high resolution rotational spectrum of 2-(trifluoromethyl)pyridine in 2\begin{document}$ - $\end{document}20 GHz was recorded and analyzed. Spectroscopic parameters including rotational constants, nuclear quadrupole coupling constants of \begin{document}$ ^{14} $\end{document}N as well as the centrifugal distortion constants were determined. The rotational spectra of five mono-substituted \begin{document}$ ^{13} $\end{document}C and one \begin{document}$ ^{15} $\end{document}N isotopologues were also measured and assigned in natural abundance. Experimental results complemented by ab initio calculations lead to an accurate determination of the skeleton structure. The values of the planar moment inertia \begin{document}$ P_{cc} $\end{document} were determined to be 44.46 u?\begin{document}$ ^2 $\end{document} for all the measured isotopologues, indicating a C\begin{document}$ _ \rm{s} $\end{document} symmetry of this molecule. The molecular electrostatic surface potential was calculated to illustrate the trifluoromethyl substitution effects on the electron distribution.     

Condensation of 2-(acetamido)cyclohexanone with malononitrile

Depending on the conditions, condensation of 2-(acetamido)-cyclohexanone with malononitrile gives 1-acetyl-2-amino-3-cyano-4,5,6,7-tetrahydroindole or 2-amino-3-cyano-4,5,6,7-tetrahydroindole, from which substituted tetrahydropyrimido[1,2-a]indole and tetrahydropyrimido [4,5-b]indole were synthesized.     

Reaction of 2-(2,4-dimethylbenzoyl)cyclohexanone with o-phenylenediamine

Russian Journal of Organic Chemistry -     

2-(1-环己烯基)环己酮的合成

以酸或碱做催化剂，环己酮自身催化缩合生成以2-(1-环己烯基)环己酮为主的缩合产物，同时还生成2-环己亚烷基环己酮，以及副产物三聚物。考察了使用酸、碱在不同反应条件下的缩合反应，试验表明，硫酸做催化剂的工艺较为可取。     

Synthesis and Crystal Structure of 1-（Trifluoromethyl）-1-（propioloyl）-（E）-3-oxo-（2-thienyl）-（2-naphthylamine）

1INTRODUCTIONTheSchiffbasesderivedfromb-diketonesandaliphaticamineshavebeenshowntoexistastheketo-amines.However,ifsubstituentseitherattheketooraminogrouparearomatic,itmaybeexpectedtheenoliminewillbethefavoredtautomericform[1].Recently,someSchiffbasesderivedfromTTA(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione)andPMBPhavebeenstudiedbyWang[2]andYu[3]etal.Inordertostudytherelationshipbetweenthestructuresandperformancesofthesecompounds,thetitlecom-poundwillbereportedherein.2EXPERIMENT…     

3-三氟甲基联苯的合成

以3-三氟甲基苯胺为原料,叔丁醇亚硝酸酯为重氮化试剂,铜粉为催化剂,采用改良的Gomberg反应合成了3-三氟甲基联苯。最佳的反应条件为：3-三氟甲基苯胺20mmol,叔丁醇亚硝酸酯的用量为3-三氟甲基苯胺摩尔数的两倍,Cu的用量为3-三氟甲基苯胺摩尔数的0．6倍,于在40℃反应5h,其结构经^1H NMR,^13C NMR和IR表征。     

Electrochemical Synthesis of 2-(2-Chlorophenyl)-2-[(3,4- dihydroxyphenyl)(methyl)amino]cyclohexanone

Russian Journal of Electrochemistry - Electrochemical oxidation of catechol has been studied in the presence of ketamine as a drug in phosphate buffer solution mixed with ethanol using voltammetric...     

A Novel and Simple Synthesis of 2-(Trifluoromethyl)-4H-thiochromen-4-ones

Abstract

Alkyl 2-mercaptophenyl ketones react with trifluoroacetic anhydride in the presence of triethylamine to give 2-(trifluoromethyl)-4H-thiochromen-4-ones, which are transformed into the corresponding pyrazoles by treatment with hydrazine hydrate and into 1,1-dioxides by oxidation with H₂O₂ in AcOH.     

Photochemistry of 1-(2,6-dichlorobenzyl)-1,4-dihydronicotinamide

The cleavage of the N-benzyl bond characterizes the photochemical behaviour of I in methanol. Beside the coupling or the hydrogen abstraction products, the interconvertible 1,4,5,6-tetrahydropyridines VIa and VIb were obtained.     

Structure of (Z)-(5R)-methyl-2-(4-phenylbenzylidene)cyclohexanone as chiral component of liquid-crystalline systems

The spatial structure of (Z)-(5R)-methyl-2-(4-phenylbenzylidene)cyclohexanone prepared by photochemical isomerization of the E-isomer was studied by analyzing the magnitudes and temperature dependence of the proton spin-spin coupling constants obtained by ¹H NMR spectroscopy and the results of molecular modeling using semiempirical quantum chemical AM1 and PM3 methods and the density functional theory (DFT). Comparison of the results obtained for the Z-and E-isomers shows that in both cases the conformational equilibrium for both isomers is characterized by significant preference of the chair conformer having an equatorial methyl group, namely, − ΔH (chair a ⇌ chair e) = 1.98–2.12 and 1.36–1.54 kcal mole⁻¹ for the Z-and E-isomers, respectively. Distinctions in the non-planarity of the enone fragment and cyclohexanone ring in the Z-and E-isomers under study following from the results of mathematical modeling were confirmed by the experimental values of the geminal spin-spin coupling constants of protons of the methylene groups in α,α ′-positions with respect to the enone group. Quantum chemical calculations of the Z-isomer revealed the existence of intramolecular hydrogen bond between the carbonyl oxygen and the nearest aromatic proton in ortho-position of the benzene ring. Possible reasons for different helical twisting power of (Z)-(5R)-methyl-2-(4-phenylbenzylidene)cyclohexanone and the E-and Z-arylidene derivatives of 1R, 4R-isomenthone in the mesophase are discussed based on the results of molecular structure studies for these compounds. In the text below the unsaturated ketones under study will be called “arylidene cyclohexanone derivatives” for convenience of comparing the characteristics of methylcyclohexanone and isomenthone derivatives. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 962–972, June, 2006.     

Synthesis of New Tandospirone Analogues Carrying 1-(3-(Trifluoromethyl)phenyl)piperazine

New tandospirone analogues containing a 1-[3-(trifluoromethyl)phenyl]piperazine (TFMPP) moiety have been synthesized by hydroarylation reactions with Pd(OAc)₂. The perhydroisoindole derivatives were obtained by the reaction of reduced starting material with aryl-(heteroaryl) iodides under the same conditions. Spiro-1,3-indandionolylpyrrolidine derivatives having an array of stereocenters are reported.