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1.
In the presence of triethylamine, 3-arylsydnone-4-carbohydroximic acid chlorides react not only with active methylene compounds containing keto groups to give 3-aryl-4-(4′,5′-disubstituted-isoxazol-3′-yl)sydnones, but also with compounds containing cyano groups to produce 3-aryl-4-(4′-substituted-5′-aminoisoxazol-3′-yl)sydnones or 3-aryl-4-(4′-cyano-5′-substituted-isoxazol-3′-yl)sydnones. 相似文献
2.
3-Arylsydnone-4-carbonitrile oxides may undergo 1,3-dipolar cycloadditions with alkenes to produce the corresponding 3-aryl-4-(5-substituted-isoxazolin-3-yl)sydnones. The direct reaction of 3-arylsydone-4-carbohydroximic acid chlorides with alkenes may also give the same products, and with higher yield. 相似文献
3.
3-Arylsydnone-4-carbonitrile oxides (2), which are generated in situ by thermal dehydrochlorination of the corresponding hydroximic acid chlorides (1), undergo 1,3-dipolar cycloadditions with sydnone-4-carbonitriles (6) to give 3-aryl-4-[5-(3-arylsydnonyl)-1,2, 4-oxadiazol-3-yl] sydnones (9). These nitrile oxides (2) also react with alkyl- and arylnitriles to give 1,3-dipolar cycloaddition products. 相似文献
4.
Mou-Yung Yeh Fat-Fong Chan Hsien-Ju Tien Toshio Fuchigami Tsutomu Nonaka 《中国化学会会志》1989,36(2):143-148
N-Hydroxy-3-arylsydnone-4-carboxamide oximes (7) were prepared from the corresponding 3-arylsydnone-4-carbohydroximic acid chlorides (6) and hydroxylamine in high yield. The chemical reactivity of compound (2) is somewhat different from 3-arylsydnone-4-carboxamide oximes (2) in that the former compounds reacted with both aromatic and aliphatic aldehydes in the presence of acid catalyst to give 3-aryl-4-(5-aryl-1,2,4-oxadiazol-3-yl)sydnones (5) and 3-aryl-4-(5-alkyl-1,2,4-oxadiazol-3-yl)sydnones (3). 相似文献
5.
3-Aryl-4-(5-aryl-Δ2-1,2,4-oxadiazolin-3-yl)sydnones (5) were synthesized in high yields by the reaction of 3-arylsydnone-4-carboxamide oximes (prepared from the corresponding 3-arylsydnone-4-carbonitriles) with aromatic aldehydes in the presence of acid catalysts. No reaction occurred when aliphatic aldehydes were used. The oxadiazolin-3-ylsydnones (5) were easily converted into the corresponding 3-aryl-4-(5-aryl-1,2,4-oxadiazol-3-yl)sydnones by N-bromosuccinimide oxidation. The 3-arylsydnone-4-carbonitrile oxides were synthesized in good yields by N-bromosuccinimide oxidation of the corresponding 3-arylsydnone-4-carboxaldehyde oximes. 相似文献
6.
The 13C NMR spectra of twelve 3-aryl-4-(5-aryl-Δ2-l,2,4-oxadiazolin-3-yl)sydnones and twelve 3-aryl-4-(5-aryl-l,2,4-oxadiazol-3-yl)sydnones have been measured and assigned by means of proton-noise decoupling and DEPT-experiments. The coupling constants were determined by means of gated decoupling, and NOE effects were observed by comparison of proton-decoupled and inverse-gated decoupled spectra. Differences shown by the oxadiazoline and the oxadiazole rings and the substitution effects are discussed. 相似文献
7.
Under various basic solutions and reaction durations, 3-substituted 4-formyIsydnones and nitroalkanes containing α-active hydrogen (e.g. nitromethane and nitroethane) are converted to β-nitroalcohols, nitroalkenes and dinitroalkanes. β-Nitroalcohols are obtained only by electrochemical reaction on an electrogenerated base (EGB). The mechanism of overall reaction steps in particular is discussed. 相似文献
8.
In the presence of base, 3-subslituted 4-fonnyl- and 4-acetylsydnones decarbonylated to afford the corresponding 3-substituted sydnones. The Claisen-Schmidt reaction occurred between 3-substituted 4-for-mylsydnones and methyl ketone (such as 4-acetylsydnones, acetone and acetophenone) in dilute basic solution or electrogenerated basic (EGB) solution. 相似文献
9.
3-Arylsydnone-4-carbohydroximic acid chlorides (1) could react with N-arylmaleimides (3a–b) or 2-methyl-N-phenylmale-imide (3c) to give 3-(3-arylsydnon-4-yl)-5-aryl-3a,6a-dihydro-pyrrolo[3,4-d]isoxazole-4,6-diones (4a–h) or 6a-methyl-3-(3-arylsydnon-4-yl)-5-phenyl-3a,6a-dihydro-pyrrolo[3,4-d]isoxazole-4,6-diones (4i–l), respectively. However, 3-(arylsydnon-4-yl)-naphtho[2,3-d]isoxazole-4,9-diones (6a–d) were obtained in good yield by the reaction of carbohydroximic acid chlorides 1 with [1,4]naphthoquinone. Furthermore, 2-(3-arylsydnon-4-yl)benzoxazoles (9a–d) and 2-(3-arylsydnon-4-yl)benzothiazoles (9e–h) were obtained via the reaction of carbohydroximic acid chlorides 1 with ortho-substituted aromatic amines 7a and b. 相似文献
10.
Hsien-Ju Tien Mou-Yung Yeh Ded-Shih Huang Yi-Lung Wu Wen-Fa Kuo Wen-Kuen Chang Jing-Chyi Chang 《中国化学会会志》1998,45(3):387-390
3-(3′-,4′-Hydroxyphenyl)sydnones were prepared by dealkylation of 3-(3′-,4′-alkoxyphenyl)sydnones with concentrated sulfuric acid at room temperature in a range of 59 to 86% yield. 相似文献
11.
Guang Xiang Zhong Lu Lu Chen Jian Li Wei Xiao Hu Min You Qi 《中国化学快报》2008,19(12):1419-1422
Eighteen 2′,4′-difluoro-3-(carbamoyl)biphenyl-4-yl benzoates were synthesized from diflunisal in three steps with total yields from 72% to 86%. All compounds were identified by IR, 1^H NMR, MS and elemental analysis. The anti-inflammatory activity and analgesic activity for 18 compounds were evaluated. The preliminary assay results showed that compounds 4a and 4p exhibited potent anti-inflammatory-analgesic activity. 相似文献
12.
Six arsenic-containing β-D -ribofuranosides, including the naturally occurring (2′R)-dimethyl[1-O-(2′,3′-dihydroxypropyl)-5-deoxy-β-D -ribofuranos-5-yl]arsine oxide, were prepared in multi-step reactions from D -ribose and tetramethyldiarsine. The synthetic procedure uses the early substitution of the hydroxy group with bromine at C5, subsequent attachment of a chiral three-carbon aglycone at C1, and final delivery of arsenic at C5. The synthesis provides a viable route for the preparation of multigram quantities of the natural product. 相似文献
13.
Reaction of 1,′, 3,3′-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphete with S? H Acidic Compounds. Reaction of 1,′,3,3′-tetrakis(dimethyl-amino)-1λ5,3λ5-diphosphete ( 1 ) with hydrogen sulfide yields bis(dimethylamino)thiophosphonylmethylidene-methyl-bis(dimethylamino)phosphorane ( 5 ).Water eliminates dimethylamine from 5 and forms bis(dimethyl-amino)thiophosphonyl-methyl(dimethylamino)phosphonylmethylene 6 . The reaction of 1 with ethylmercaptane yields the 2,4-bis(ethylthio)-derivative of 1 , i.e. compound 8 and bis(dimethylamino)phosphanylmethylidene-methyl-bis(dimethylamino)phosphorane ( 9 ), which is also formed from 1 and 2,4,6-trimethylphenylphosphane. Thiophenol protonates 1 to give the corresponding cation which is isolated as its thiophenolate, 10 . Properties, nmr and mass spectra of 5, 6 and 8 – 10 are described and discussed. 相似文献
14.
Silicon-Containing Spirocyclic Phosphorus(V) Hydrazine Heterocycles In the reaction of 1,1-dichlorosilacyclohexane with dihydrazido thiophosphoric acid O-phenylester in a 1:1 molar ratio in THF as solvent and in the presence of triethylamine mainly the expected spirocyclic system of inorganic and organic heterocycle is formed with the Si atom as spirocenter (ms, nmr). In addition and in low yield crystalls of a dimeric compound are isolated. A single crystall x-ray analysis reveals this compound to consist of a dispiro system with a central centrosymmetric eightmembered inorganic heterocycle connected with two silacyclohexanes via Si spirocenters. 相似文献
15.
The 2-aryl-3-iodo-4-(phenylamino)quinolines undergo one-pot palladium-mediated C-I and C-H bond activation and subsequent Suzuki-Miyaura cross-coupling with arylboronic acids under anhydrous conditions to afford mixture of 2,3-diaryl-4-(phenylamino)quinolines (minor) and 2-aryl-4-([(1,1′-biaryl)-2-yl]amino)quinoline derivatives (major). The 2,3-diaryl-4-(phenylamino)quinolines were isolated as major products when 2 M K2CO3 was used as a base. A plausible mechanism, which implicates a six-membered palladacycle intermediate is proposed for the formation of the observed mixture of products. The prepared compounds were characterized using a combination of spectroscopic and X-ray crystallographic techniques. 相似文献
16.
A homogeneous catalyst, 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride, for addition of aldehydes to activated double bond, was attached to 20% cross-linked polystyrene-divinylbenzene copolymer. The attached catalysts could be easily removed from the reaction mixture. Polymer-attached thiazolium salts in the presence of triethylamine are active catalysts for addition of aromatic and aliphatic aldehydes to α,β-unsaturated ketones to yield γ-diketones. 相似文献
17.
Jinghua Yu Bo Li Ping Dai Shenguang Ge Xiaoliang Cheng 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(4):875-880
In this paper the resonance Rayleigh scattering (RRS) and second-order scattering (SOS) spectrums of interaction between deoxyribonucleic acid (DNA) and 3-(4′-methylphenyl)-5-(2′-sulfophenylazo) rhodanine (4MRASP) in the environment of surface active substance sodium dodecyl sulfate (SDS) were reported. The light scattering intensity of 4MRASP was enhanced obviously and directly proportional to the concentrations of DNA when DNA was present. Based on this, two new determination methods of DNA were established with high sensitivity and selectivity, and the limits of detection were 8.00 and 1.07 ng mL−1. They were applied to the determination of trace amounts of nucleic acid in synthetic and practical samples with satisfactory results. At last, the active mechanism among molecules was studied by ultraviolet spectrum, scattering spectrum and thermodynamics, which showed that the active force was changed from hydrophobic force to electrostatic force before and after SDS was added, and the mechanism of sensitization effect of SDS was proposed. 相似文献
18.
A convenient method to prepare 4-formyl-3-arylsydone (I) from 3-arylsydnone by the Vilsmeier reaction in moderate yields (30%-76%) was carefully investigated. According to the Schmidt reaction, I reacts with sodium azide in concentrated sulfuric acid to produce 3-arylsydnone-4-carboxamide (II). But 3-arylsydnone-4-carhonitrile (III) is obtained, if dilute sulfuric acid was used instead. When III treates with concentrated sulfuric acid, II is obtained in good yield. The all possible reaction mechanisms are suggested. 相似文献
19.
The acid dissociation constant, pKa, for the ground and excited states of ruthenium tris(4′-methyl-2,2′-bipyridine-4-carboxylic acid) complex have been measured. The ground state pKa obtained from the pH titration curve of the complex absorption at 454 nm was 2.5. The lifetimes of the excited-state for deprotonated and protonated ruthenium complexes are 595 and 150 ns, respectively. The excited-state pKa* is obtained from the emission titration curve at 630 nm and corrected for the excited-state lifetime to be 4.2. The increase of 1.7 pH units in the acid dissociation constant in the excited-state indicates that the ligand is much more basic in the excited-state. This result confirms the MLCT assignment for the lowest electronic transition of [Ru(mbpyCOOH)3]2+. 相似文献
20.
In the presence of pyridine, 3-aryl-4-formylsydnone (II) reacts with hydroxyl-amine hydrochloride to produce 3-aryl-4-formylsydnone oxime (III). This reaction was performed in ethanol solution with reflux or at room temperature; the latter procedure gave an excellent yield (74-98%) and high purity. (III) reacts in acetic anhydride at room temperature to give 3-aryl-4-formylsydnone oxime O-acetate (IV). A convenient method for the synthesis of 3-aryl-4-cyanosydnone (V) is to dehydrate (III) with acetic anhydride at reflux. When (IV) was refluxed with acetic anhydride, (V) was similarly obtained. Another convenient method to prepare (V) from (III), dehydration with thionyl chloride at room temperature, was also investigated. 相似文献