Fluorocarbon derivatives of nitrogen. Part 11. Synthesis of some 2-(trifluoromethyl)imidazo[1,2-a]pyridines from trifluoroacetonitrile

3-(t-Butoxycarbonyl)-2-(trifluoromethyl)imidazo[1,2-$\text{a}$]-pyridine, prepared from trifluoroacetonitrile and pyridinium t-butoxycarbonylmethylide, reacts smoothly with trifluoroacetic acid to provide 2-(trifluoromethyl)imidazo[1,2-$\text{a}$]pyridine-3-carboxylic acid, which gives 2-(trifluoromethyl)imidazo[1,2-$\text{a}$]-pyridine when heated. 3-Cyano-2-(trifluoromethyl)imidazo[1,2-$\text{a}$]pyridine can be obtained $\text{via}$ treatment of trifluoroacetonitrile with pyridinium cyanomethylide, which is sufficiently reactive to effect nucleophilic displacement of fluorine from pentafluoropyridine under mild conditions [→pyridinium cyano(tetrafluoro-4-pyridyl)methylide].     

2-甲基-N-[4-硝基-3-三氟(甲基)苯基]丙酰胺的改进合成

以3－三氟里基苯为原料,在吸酸剂碳酸氢钠作用下与2－甲基丙酰氯反应得到2－甲基－N－[4－硝基－3－三氟（甲基）苯基]丙酰胺,再进行混酸硝化得到目标化合物。     

The kinetics and the mechanism of the thermal gas-phase reaction between bis(trifluoromethyl)trioxide,CF3O3CF3 and 1,1-dichlorodifluoroethylene,CF2CCI2

The thermal addition of CF₃O₃CF₃(T) to CF₂CCl₂(E) has been investigated between 49.6 and 69.5°C. The initial pressure of CF₃O₃CF₃ was varied between 7 and 240 torr and that of CF₂CCl₂ between 4 and 600 torr. Four products of formula CF₃O(E)_j OOCF₃, where j = 1 → 4 are formed. The sum of the products Σ CF₃O(E)_jOOCF₃ is equal to the amount of trioxide decomposed. The reaction is homogeneous. Its rate is not affected by the total pressure and the presence of inert gas. It is a free radical telomerization with four basic steps: thermal decomposition of CF₃O₃CF₃ into CF₃O^. and CF₃O₂^., chain initiation by addition of CF₃O^. to olefin incorporated in, and telomeric radicals termination. The consumption of alkene is well represented by the equation: where (d[E]/d[T]) = is the mean chain length of telomerization. varies from 1.45 at 1.5 torr of E to 3.3 at 400 torr of E. Above this pressure E has no influence on . The estimated value of the constant for the addition of telomeric radicals to alkene is:      

Preparations of bis[2-(2-arylethynyl)-3-thienyl]arenes and bis[2-{2-(trimethylsilyl)ethynyl}-3-thienyl]arenes

4,4′-Bis[2-(2-phenylethynyl)-3-thienyl]biphenyl, 4,4′-bis[2-{2-(trimethylsilyl)ethynyl}-3-thienyl]biphenyl and their congeners were prepared and their properties were studied. Extension of π-system through the central benzene ring was suggested by UV-vis spectra. Connection of two 1,4-bis[2-{2-(trimethylsilyl)ethynyl}-3-thienyl]benzene units was exemplified.     

Studies on hypolipidemic agents. IV. 3-[4-(Phenylthio)benzoyl]propionic acid derivatives

2-Acetylthio-3-benzoylpropionic acid derivatives having two benzene rings or condensed-ring moieties were prepared, and tested for hypolipidemic activity in normal rats. Some of these compounds were active. 2-Acetylthio-3-[4-(phenylthio)benzoyl]propionic acid (10) and its derivatives seemed to have the most potent hypocholesterolemic activities. Compound 10 showed strong activity, especially in cholesterol-fed rats.     

Bis(dimethylamino)trifluoromethylsulfonium Salze: [CF3S(NMe2)2]+[Me3SiF2]‐, [CF3S(NMe2)2]+[HF2]‐ und [CF3S(NMe2)2]+[CF3S]‐

Bis(dimethylamino)trifluoro sulfonium Salts: [CF₃S(NMe₂)₂]⁺[Me₃SiF₂]^‐, [CF₃S(NMe₂)₂]⁺ [HF₂]^‐ and [CF₃S(NMe₂)₂]⁺[CF₃S]^‐ From the reaction of CF₃SF₃ with an excess of Me₂NSiMe₃ [CF₃(NMe₂)₂]⁺[Me₃SiF₂]^‐ (CF₃‐BAS‐fluoride) ( 5 ), from CF₃SF₃/CF₃SSCF₃ and Me₂NSiMe₃ [CF₃S(NMe₂)₂]⁺‐ [CF₃S]^‐ ( 7 ) are isolated. Thermal decomposition of 5 gives [CF₃S(NMe₂)₂]⁺ [HF₂]^‐ ( 6 ). Reaction pathways are discussed, the structures of 5 ‐ 7 are reported.     

Reactions of 5-[3-(trifluoromethyl)-phenyl]furan-2-carbaldehyde

The Knoevenagel condensations of 5-[3-(trifluoromethyl)phenyl]furan-2-carbaldehyde with seven compounds containing an active methyl or methylene group have been studied. The compounds used were: methyl 2-cyanoacetate, malononitrile, 2-furylacetonitrile, acetophenone, 2-thioxo-1,3-thiazolidin-4-one (rhodanine), 5,5-dimethylcyclohexane-1,3-dione (dimedone), and methyl 2-azidoacetate. The effect of microwave irradiation on the condensation reactions was studied and compared with “’classical”’ conditions. Thermolysis of methyl 2-azido-3-{5-[3-(trifluoromethyl)phenyl]-2-furyl}propenoate afforded methyl 2-[3-(trifluoromethyl)phenyl)]-4H-furo[3,2-b]pyrrole-5-carboxylate. (2E)-3-{ 5-[3-(Trifluoromethyl)phenyl]-2-furyl}propenoic acid was converted to the corresponding azide, which was cyclized on heating into 2-[3-(trifluoromethyl)phenyl)]-4,5-dihydrofuro[3,2-c]pyridin-4-one. The latter after successive action of POCl₃ and NH₂NH₂-Pd/C gave 2-[3-(trifluoromethyl)-phenyl]furo[3,2-c]pyridine. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 825–831, June, 2006.     

Synthesis of 2-[3′-(trifluoromethyl)anilino] -5-hydroxynicotinic acid

2-[3′-(Trifluoromethyl)anilino]-5-hydroxynicotinic acid (2) was synthesized by two routes: a) by direct hydroxylation of 2-[3′-(trifluoromethyl)anilino]nicotinie acid (1) ; and b) by the following sequence starting from 2-chloro-3-methyl-5-nitropyridine (3) via 5-amino-2-chloro-3-methylpyridine (4) , 2-ehloro-5-hydroxy-3-methylpyridine (6) , 5-acetoxy-2-chloro-3-methylpyridine (7) , 5-acetoxy-2-chloronicotinie acid (8) , and 2-chloro-5-hydroxynicotinic acid (9). The correlation of 2 with one of the metabolites of 1 has been accomplished, and the identities of both compounds have been proven.     

Synthesis of 2-[3-(trifluoromethyl)phenyl]furo[3,2-<Emphasis Type="Italic">c</Emphasis>]pyridine derivatives

2-[3-(Trifluoromethyl)phenyl]-4,5-dihydrofuro[3,2-c]pyridin-4-one (I) was prepared by a three-step synthesis. Its reaction with phosphorus sulfide rendered thione II which was methylated to 2-[3-(Trifluoromethyl)phenyl]-4-methylsulfanylfuro[3,2-c]pyridine (III). 5-Methyl-2-[3-(trifluoromethyl)phenyl]-4,5-dihydrofuro[3,2-c]pyridin-4-one (IV) was obtained by the reaction of I with methyl iodide in PTC conditions. The chlorine atom in derivate V was replaced with heterocyclic secondary amines via nucleophilic substitution and 4-substituted furopyridines VIa and VIb were thus prepared. 2-[3-(Trifluoromethyl)phenyl]furo[3,2-c]pyridine-4-carboxylic acid (VII) was obtained by hydrolysis of the corresponding carbonitrile Va.     

Reaction of CF3 radicals with CO and O2. Isolation of bis(trifluoromethyl)peroxydicarbonate,CF3OC(O)OOC(O)OCF3, and identification of bis(trifluoromethyl)trioxydicarbonate,CF3OC(O)OOOC(O)OCF3

The synthesis of CF3OC(O)OOCF3, CF3OC(O)OOC(O)OCF3, and CF3OC(O)OOOC(O)OCF3 is accomplished by the photolysis of a mixture of (CF3CO)2O, CO, and O2. Pure CF3OC(O)OOCF3 and CF3OC(O)OOC(O)OCF3 are isolated after thermal decomposition of CF3OC(O)OOOC(O)OCF3 and repeated trap-to-trap condensation. Additional spectroscopic data of known CF3OC(O)OOCF3 are obtained by recording NMR, IR, Raman, and UV spectra: At room temperature CF3OC(O)OOC(O)OCF3 is stable for days in the liquid or gaseous state. The melting point is -38 degrees C, and the boiling point is extrapolated to 73 degrees C from the vapor pressure curve log p = 8.657-1958/T (p/mbar, T/K). The new compound is characterized by molecular mass determination and by NMR, vibrational, and UV spectroscopy. The new trioxide CF3OC(O)OOOC(O)OCF3 cannot be separated from CF3-OC(O)OOC(O)OCF3 by distillation due to their similar boiling points. CF3OC(O)OOOC(O)OCF3 decomposes at room temperature within hours into a mixture of CF3OC(O)OOC(O)OCF3, CF3OC(O)OOCF3, CO2, and O2. Its characterization is discussed along with a possible mechanism for formation and decomposition reactions.     

Kinetics of the thermal decomposition of bis(trifluoromethyl) peroxydicarbonate,CF3OC(O)OOC(O)OCF3

Thermal decomposition of bis(trifluoromethyl) peroxydicarbonate has been studied. The mechanism of decomposition is a simple bond fission, homogeneous first‐order process when the reaction is carried out in the presence of inert gases such as N₂ or CO. An activation energy of 28.5 kcal mol^?1 was determined for the temperature range of 50–90°C. Decomposition is accelerated by nitric oxide because of a chemical attack on the peroxide forming substances different from those formed with N₂ or CO. An interpretation on the influence of the substituents in different peroxides on the O? O bond is given. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 15–19, 2003     

Domino carbocationic rearrangement of alpha-[bis(methylthio)methylene]alkyl-2-(3/2-indolyl) cyclopropyl ketones

Domino carbocationic rearrangement of a number of substituted 3- and 2-indolylcyclopropyl ketones with an alpha-bis(methylthio)methylene group in the presence of various protic/Lewis acids yields a variety of products, mainly the pentaleno fused indoles and the carbazole derivatives.     

A mass spectrometric investigation on some 3-[2-(Nitroxy)alkyl]-2H-1,3-benzoxazin-4-(3H)-one derivatives

The electron ionization mass spectrometric behaviour of ten 3-[2-(nitroxy)alkyl]-2H-1,3-benzoxazin-4-(3H)-one derivatives has been studied by means of metastable ion studies. By mass-analysed ion kinetic energy spectrometry of the related molecular ions, clear differences have been evidenced between the 5-methyl derivative and the other compounds, consisting of a highly favoured loss of NO₂ radical. The same methodology has allowed easy characterization of isomeric compounds.