Several new pyridine derivatives were prepared via reaction of enaminoketones 1a , 1b , 1c , 1d with active hydrogen reagents. Reaction of the enaminoketones 1a , 1b , 1c with 4‐acetyl‐1,5‐dimethyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐one 2a yielded the pyridines 3a , 3b , 3c . Condensation of the enaminonitrile 1d with compounds 2b , 2c , 2d and compound 8 gave the pyridine derivatives 6a , 6b , 6c and 10 respectively. Also, (3‐(dimethylamino)acryloyl)‐2H‐chromen‐2‐one 1a reacted with active methylenes in diethyl 3‐oxopentanedioate 12 and 4‐methyl‐6‐oxo‐2‐thioxo‐1,2,5,6‐tetrahydropyridine‐3‐carbonitrile 15 to afford the pyridine derivatives 14 and 16 respectively. 相似文献
Compounds 1,3,6,6a‐tetraphenyl‐1,6a‐dihydrocyclopenta[c]pyrazol‐4(3aH)‐ones ( 3 ), 1,3,3a,4‐tetraphenyl‐1,3a‐dihydrocyclopenta[c]pyrazol‐6‐ols ( 4 ) and 6‐hydroxy‐1,3,6,6a‐tetraphenyl‐1,5,6,6a‐tetrahydrocyclopenta[c]pyrazole‐4(aH)‐one ( 5 ) were synthesized by reaction of 3,4‐diphenyl‐4‐hydroxy‐2‐cyclopentenone ( 2a ) with nitrilimines, generated in situ by the action of triethylamine on the corresponding hydrazonyl chlorides 1 . 相似文献
Reaction of 3,6‐dichlorocarbazole with propargyl bromide in the presence of a basic medium gave an N‐propargylated carbazole. The latter compound was converted into molecular architectures containing 1,2,3‐triazole moiety through Cu(I)‐catalyzed 1,3‐cycloaddition reaction with different azides. Similarly, 2‐azidomethyl benzothiazole was cliched with N‐Boc‐protected N´‐propargyl glutamate to give the biomolecule 2‐triazolylmethyl product. 相似文献
The reaction of the stabilized phosphonium ylides 2a , 2b with indolinones 1a , 1b and naphthofuranone 13 afforded the corresponding propylidene and ethylidene derivatives 4a , 4b , 4c , 4d and 14a , 14b . On the other hand, the active phosphacumulenes 5a , 5b react with compounds 4a , 4b , 4c , 4d by [4 + 2]‐cycloaddition to give the stable phosphanylidene indole pyranones 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h . Although compounds 14a , 14b afforded the naphthofuropyrans 16a , 16b , 16c , 16d and triphenylphosphane. Moreover, the phosphallene ylide 7 react with compounds 4a , 4b , 4c , 4d and 14a , 14b to give phosphanylidenecyclobuteneindoline 9a , 9b , 9c , 9d and naphthalenones 18a , 18b , respectively. In addition, the naphthofuropyridazine 21 was obtained from the reaction of the hydrazone 19 and the phosphacumulene 5a . The antitumor activity of some of the new compounds was evaluated, in vitro, against colon and hepatocellular carcinoma cell lines. They showed values closed to that recorded by the reference drug Doxorubicin. 相似文献
4‐Amino‐3‐methyl‐1‐phenyl‐1H‐thieno[2,3‐c]pyrazole‐5‐carboxamide ( 5 ), which was synthesized by an innovative method, was used as a versatile precursor for synthesizing pyrazolothienopyrimidines and imidazopyrazolothienopyrimidines compounds. Reaction of amino thienopyrazole carboxamide 5 with triethyl orthoformate afforded thienopyrazolopyrimidine 6 . Chlorination of the latter compound, using phosphorus oxychloride afforded the chloro pyrazolothienopyrimidine 7 , which underwent nucleophilic substitution reactions with various primary and secondary amines to give the alkyl (aryl) amino pyrimidine compounds 8a–d . On the other hand, the reaction of chloropyrimidine 7 with thiourea afforded the pyrimidine thione compound 9 , which was alkylated with α‐halogentaed compounds to afford the S‐alkylated derivatives 10a–c . Also, chloroacetylation of the amino carboxamide 5 using chloroacetyl chloride yielded the chloromethyl pyrazolothienopyrimidine 12 , which underwent nucleophilic substitu‐ tion reactions with various primary and secondary amines to afford the alkyl (aryl) aminomethyl compounds 13a–f . The latter Compounds underwent Mannich reaction to give imidazopyrimidothieno‐ pyrazoles 14a–c . The newly synthesized compounds and their derivatives were fully characterized by elemental and spectral analysis. 相似文献
Energetics of intramolecular cycloadditions of azidoenynes and azidobutenenitriles to give 6H‐pyrrolo[1,2‐c][1,2,3]triazoles and 5H‐pyrrolo[1,2‐d]tetrazoles have been calculated at the B3LYP/6.311++G(3df,3pd) level of theory in ideal gas and in H2O as solvent. Stabilities of the corresponding anions, tautomers, and isomers are discussed. Transition states of the cyclization of parent compounds are determined at the same level of theory. 相似文献
In this paper, the effects of functionalization with terpenes on two new liquid-crystalline stationary phases for gas chromatography (GC) are described. Citronellol was used as the terminal group in the first material, and tetrahydrogeraniol was used with a second material. Inverse GC showed that the new materials have wide liquid-crystalline ranges (mesophases), 371–500 and 395–501 K, respectively. Moreover, they show good thermal stability up to 523 K and good potential as stationary phases for capillary GC. To clarify the effects of the liquid crystal structures and functional groups on retention and separation, the chromatographic behaviors of the two stationary phases were compared by eluting alkylbenzenes, polycyclic aromatic hydrocarbons, aromatic compounds, and terpenoids. The selectivities for a wide range of analytes achieved using the citronellol column were significantly better than those obtained using the tetrahydrogeraniol column. The columns showed different retention behaviors and fine resolutions for some of the main constituents of essential oils. Introduction of the double bond of citronellol greatly improved the polarization interactions involved in the shape recognition of the liquid-crystalline state for isomers. The new citronellol liquid-crystalline stationary phase, therefore, has a high affinity for natural compounds.
A series of photochromic derivatives based on the trans‐10b,10c‐dimethyl‐10b,10c‐dihydropyrene (DHP, “closed form”) skeleton has been synthesized and their photoisomerization leading to the corresponding cyclophanediene (CPD, “open form”) isomers has been investigated by UV/Vis and 1H NMR spectroscopies. Substitution of the DHP core with electron‐withdrawing pyridinium groups was found to have major effects on the photoisomerization efficiency, the most remarkable examples being to enhance the quantum yield of the opening reaction and to allow fast and quantitative conversions at much lower radiant energies. This effect was rationalized by theoretical calculations. We also show that the reverse reaction, that is, going from the open form to the closed form, can be electrochemically triggered by oxidation of the CPD unit and that the photo‐opening properties of pyridine‐substituted DHPs can be efficiently tuned by protonation, the system behaving as a multi‐addressable molecular switch. These multi‐addressable photochromes show promise for the development of responsive materials. 相似文献
Homodisperse doped polyoxotitanate nanoclusters with formulae Ti11(MX)O14(OiPr)17 (M=Mn, Fe or Co; X=Cl, Br or I, OiPr=isopropoxide) display strongly dopant‐dependent properties. Spectroscopic solution and reflectance measurements backed up by density of states and time‐dependent DFT calculations based on the determined structures, show the prominent effect of FeX substitution by decreasing the HOMO–LUMO gap of the particles. The effect is attributed to the presence of an occupied Fe β orbital halfway up the bandgap, leading to long‐wavelength absorption with electron transfer to the titanium atoms of the cluster. Whereas the light absorption varies significantly with variation of the transition metal dopant, its dependency on the nature of the halogen atom or the change in dipole moment across the series is minor. 相似文献