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1.
A. A. Konarev E. A. Lukyanets V. M. Negrimovskii 《Russian Journal of Electrochemistry》2007,43(11):1252-1259
The electroreduction of methyl 5-nitro-4-oxopentanate was studied by means of a polarographic method and preparative electrolysis in acidic-alcoholic solutions. The effects of the following factors on the yield and quality of 5-amino-4-oxopentanoic acid hydrochloride were studied: the cathode material, amount of electricity, temperature, nature of the solvent, concentrations of the initial nitro compound and hydrochloric acid, and the cell design. It was shown by electrolysis at a controlled potential and in a galvanostatic mode that the products of methyl 5-nitro-4-oxopentanate electroreduction are hydroxyamino and amino compounds, and also ammonium chloride, nitromethane, methylhydroxylamine hydrochloride, and monomethylamine hydrochloride. Their ratio depends on the electrolysis conditions. The highest overall substance yield (61.1–66.0%) and current yield (68.1–68.6%) of 5-amino-4-oxopentanoic acid hydrochloride was achieved at a copper cathode in a filter-press cell. The content of the main substance in the electrochemically obtained samples of 5-amino-4-oxopentanoic acid was 89.5–91.0%. 相似文献
2.
Oleh V. Shablykin Volodymyr S. Brovarets Olga V. Shablykina 《Chemical record (New York, N.Y.)》2024,24(2):e202300264
The recyclizations of 5-amino- and 5-hydrazine-1,3-oxazoles mainly with electron-withdrawing group in 4th position are considered. The chemical behavior of these heterocycles is due to the presence of two hidden amide fragments; therefore, the recyclization processes include a stage of nucleophile attack on 2nd or 5th position of the oxazole cycle. When the nitrile group is present in 4th position, it is often involved in the recyclization forming α-aminoazoles. 5-Amino/hydrazine-1,3-oxazoles undergo recyclization both in nucleophilic (amines, hydrazine, thionating agents) and electrophilic medium ((trifluoro)acetic acid, other acylating agents). The numerous types of functionalized heterocycles can be easily obtained with the usage of these recyclizations, such as the derivatives of 3-amino-6,7-dihydro-5H-pyrrolo[1,2–a]imidazole, imidazolidine-2,4-dione, 1H-pyrazole-3,4,5-triamine, 5,6-diamino-2,3-diphenylpyrimidin-4(3H)-one, 2-(2-R-7-oxo-5-(trifluoromethyl)oxazolo[5,4–d]pyrimidin-6(7H)-yl)acetic acid, 2-R-4-(5-R′-1,3,4-oxadiazol-2-yl)oxazol-5-amine, (amino(5-amino-1,3,4-thiadiazol-2-yl)methyl)phosphonate. 相似文献
3.
3-氨基-4-氧代氰基呋咱捕获与表征 总被引:1,自引:0,他引:1
3,4-双(4-氨基呋咱-3-基)氧化呋咱由活性中间体3-氨基-4-氧代氰基呋咱分子间发生二聚获得,但3-氨基-4-氧代氰基呋咱不稳定,无法通过分离、纯化及光谱鉴定证实其存在.采用4种不同的烯烃与3-氨基-4-氧代氰基呋咱发生1,3-偶极环加成反应得到3-(4-氨基呋咱-3-基)-5-氰基-Δ2-异噁唑啉、3-(4-氨基呋咱-3-基)-5-乙酰氧基-Δ2-异噁唑啉、3-(4-氨基呋咱-3-基)-5-正丁基-Δ2-异噁唑啉及3-(4-氨基呋咱-3-基)-环己烷并-Δ2-异噁唑啉4种Δ2-异噁唑啉衍生物;采用苯甲酰氯为捕获剂,与3-氨基-4-氧代氰基呋咱反应获得了3-氨基-4-(N-苯甲酸基氨基羰基)呋咱化合物;通过红外光谱、核磁共振光谱、质谱、元素分析表征了5种新化合物的结构,提供了活性中间体3-氨基-4-氧代氰基呋咱存在的间接证据. 相似文献
4.
《合成通讯》2013,43(22):3449-3454
ABSTRACT A series of substituted 5-oxo-1,2,3,4,5,6,7,8-octahydroquinoline derivatives have been synthesized from 5,5-dimethyl-1,3-cyclohexane-dione (dimedone) and 1,3-diaryl-2-propen-1-one in DMF at 80°C in the presence of ammonium acetate with high yields (64–98%), the structure of the product was confirmed by X-ray analysis. 相似文献
5.
Toyoharu Miyagawa Fumio Sanda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2001,39(10):1629-1633
The alkali hydrolysis of poly(2,2-dimethyl-5-methylene-1,3-dioxolan-4-one) and poly(2,2-dimethyl-5-methylene-1,3-dioxolan-4-one-co-styrene) was carried out with a sodium hydroxide solution (40%) in tetrahydrofuran at room temperature to obtain poly(α-hydroxyacrylic acid) or poly(α-hydroxyacrylic acid-co-styrene) with number-average molecular weights of 39,000–73,000 in 41–86% yields. The styrene unit in the hydrolyzed copolymer hindered the formation of a lactone ring. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1629–1633, 2001 相似文献
6.
A. A. Bogolyubov N. B. Chernysheva V. V. Nesterov M. Yu. Antipin V. V. Semenov 《Chemistry of Heterocyclic Compounds》2003,39(8):1065-1071
X-ray diffraction structural analysis was used to show the structure of one of the two products of the reaction of benzylhydrazine with 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one and of the only product of the reaction of phenylhydrazine with the same dioxolanone. Both compounds are derivatives of 3-amino-4-hydroxyoxazolidin-2-one. 相似文献
7.
V. N. Britsun I. M. Bazavova V. N. Bodnar A. N. Chernega M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2005,41(1):105-110
Treatment of 4-arylamino-4-thioxo-2-butanones with methylhydrazine in acetic acid gives 5-arylamino-1,3-dimethylpyrazoles which are readily halogenated in the 4 position. The thermal decomposition of 3-anilino-1,2,5-trimethyl-1H-pyrazolium chloride gives 1,3-dimethyl-5-phenylaminopyrazole and 1,5-dimethyl-3-phenylaminopyrazole in the approximate ratio of 1:1.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 120–126, January, 2005. 相似文献
8.
Yuxia Liu Charles E. Keller Charles U. Pittman 《Journal of polymer science. Part A, Polymer chemistry》1997,35(17):3707-3716
Pure 1,2-addition polymers, poly(2-methylene-1,3-dioxolane), 1b , poly(2-methylene-1,3-dioxane), 2b , and poly(2-methylene-5,5-dimethyl-1,3-dioxane), 3b , were prepared using the cationic initiators H2SO4, TiCl4, BF3, and also Ru(PPh3)3Cl2. Small ester carbonyl bands in the IR spectra of 1b and 2b were observed when the polymerizations were performed at 80°C ( 1b ) and both 67 and 138°C ( 2b ) using Ru(PPh3)3Cl2. The poly(cyclic ketene acetals) were stable if they were not exposed to acid and water. They were quite thermally stable and did not decompose until 290°C ( 1b ), 240°C ( 2b ), and 294°C ( 3b ). Different chemical shifts for axial and equatorial H and CH3 on the ketal rings were found in the 1H NMR spectrum of 3b at room temperature. High molecular weight 3b (M̄n = 8.68 × 104, M̄w = 1.31 × 105, M̄z = 1.57 × 105) was obtained upon cationic initiation by H2SO4. Poly(2-methylene-1,3-dioxane), 2b , underwent partial hydrolysis when Ru(PPh3)3Cl2 and water were present in the polymer. The hydrolyzed products were 1,3-propanediol and a polymer containing both poly(2-methylene-1,3-dioxane) and polyketene units. The percentages of these two units in the hydrolyzed polymer were about 32% polyketene and 68% poly(2-methylene-1,3-dioxane). No crosslinked or aromatic structures were observed in the hydrolyzed products. The molecular weight of hydrolyzed polymer was M̄n = 5740, M̄w = 7260, and M̄z = 9060. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3707–3716, 1997 相似文献
9.
Manouchehr Mamaghani Mona Jamali Moghadam Rogheyeh Hossein Nia 《Journal of the Iranian Chemical Society》2017,14(2):395-401
In this investigation, an efficient and ecofriendly multicomponent reaction is described for the green synthesis of 2-amino-5-arylpyrimido[4,5-b]quinolinedione derivatives using ZrO2 (NPs). In this protocol, the reaction of 2,6-diaminopyrimidin-4(1H)-one, arylaldehyde and 1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione in the presence of ZrO2 (NPs) in ethylene glycol at 120 °C produced the desired products in excellent yields (90–98 %) and short reaction times (8–60 min.). Use of recyclable catalyst, green solvent, easy workup and excellent yields are the notable features of this method. 相似文献
10.
Mészáros Szécsényi K. Leovac V. M. Jaćimović Ž. K. Češljević V. I. Kovács A. Pokol G. Gál S. 《Journal of Thermal Analysis and Calorimetry》2001,63(3):723-732
We report the synthesis and the characterization (elemental analysis, FT-IR spectroscopy, thermal methods and molar conductivity
measurements) of the mixed complexes of zinc with acetate and 3-amino-5-methylpyrazole, HL
1, [Zn(OAc)2(HL1)2], or 3-amino-5-phenylpyrazole, HL
2 [Zn(OAc)2(HL2)2], or 4-acetyl-3-amino-5-methylpyrazole, HL
3, [Zn(OAc)(L3)(HL3)]2, with isothiocyanate and HL
2 [Zn(SCN)2(HL2)2], or HL
3 [Zn(SCN)2(HL3)2], and with nitrate, isothiocyanate and 3,5-dimethyl-1-carboxamidinepyrazole, HL
4 [Zn(NO3)(NCS)(HL4)2].
The thermal decomposition of the complexes is generally continuous resulting zinc oxide as end product,except [Zn(OAc)(L3)(HL3)]2 in which case a well-defined intermediate was observed between 570–620 K. On the basis of the IR spectra and elemental analysis
data of the intermediate a decomposition scheme is proposed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
《Analytical letters》2012,45(12):2535-2542
Abstract A glucose sensor based on glucose oxidase and a new mediator - 4,5-dimethyl-4′-methylthio-Δ 2,2′-bi-1,3-dithiole (MTTTF) is described. The background for sensor action is the effective MTTTF cation interaction (apparent bimolecular constant (2.0+/-0.5)?106 M?1 s?1 at 25°C and pH 7.0) with reduced glucose oxidase and the high electrochemical rate of mediator transformation. A glucose sensor was prepared by adsorbing mediator (MTTTF) and glucose oxidase on graphite rods. The sensor responds to glucose at electrode potentials higher than 50 mV vs SCE, but the maximal activity is obtained at a potential of 250 mV. In air saturated solution the electrode shows a non-linear calibration curve with a half-saturation concentration 10.4 mM and Hill coefficient 2.08 at 250 mV. Sensor response changes little at pH 6.5–8.0. The energy of activation of the sensor response calculated from the Arrhenius equation was 64.5 kJ/mol, and the temperature coefficient at 25°C was 9.2%. 相似文献
12.
S. M. Ramsh A. V. Smirnova S. Yu. Solovyova Song Minyan 《Chemistry of Heterocyclic Compounds》2008,44(1):92-95
Mechanisms are given for reactions taking place upon heating 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one in a medium consisting
of a secondary amine.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 111–114, January, 2008. 相似文献
13.
K. A. Krasnov V. G. Kartsev A. S. Gorovoi V. N. Khrustalev 《Chemistry of Natural Compounds》2002,38(5):450-457
The three-dimensional structure of 1,3-dimethyl-5-(4-allyloxybenzyl)-5-cytisylmethylbarbituric acid was found by x-ray structure analysis. A conformation with proximal cytisine and 2,4,6-trioxopyrimidine moieties was observed. Analogous structures for other synthesized 1,3-dimethyl-5-arylmethyl-5-cytisylmethylbarbituric acids and their 2-thio analogs were proved and the intramolecular effects caused by mutual magnetic shielding of spatially proximal groups were studied using PMR. 相似文献
14.
David T. Williamson Lars Kilian Timothy E. Long 《Journal of polymer science. Part A, Polymer chemistry》2005,43(6):1216-1227
The living synthesis of poly(1,3‐cyclohexadiene) was performed with an initiator adduct that was synthesized from a 1:2 (mol/mol) mixture of N,N,N′,N′‐tetramethylethylenediamine (TMEDA) and n‐butyllithium. This initiator, which was preformed at 65 °C, facilitated the synthesis of high‐molecular‐weight poly(1,3‐cyclohexadiene) (number‐average molecular weight = 50,000 g/mol) with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight = 1.12). A plot of the kinetic chain length versus the time indicated that termination was minimized and chain transfer to the monomer was eliminated when a preformed initiator adduct was used. Chain transfer was determined to occur when the initiator was generated in situ. The polymerization was highly sensitive to both the temperature and the choice of tertiary diamine. The use of the bulky tertiary diamines sparteine and dipiperidinoethane resulted in poor polymerization control and reduced polymerization rates (7.0 × 10−5 s−1) in comparison with TMEDA‐mediated polymerizations (1.5 × 10−4 s−1). A series of poly(1,3‐cyclohexadiene‐block‐isoprene) diblock copolymers were synthesized to determine the molar crossover efficiency of the polymerization. Polymerizations performed at 25 °C exhibited improved molar crossover efficiencies (93%) versus polymerizations performed at 40 °C (80%). The improved crossover efficiency was attributed to the reduction of termination events at reduced polymerization temperatures. The microstructure of these polymers was determined with 1H NMR spectroscopy, and the relationship between the molecular weight and glass‐transition temperature at an infinite molecular weight was determined for polymers containing 70% 1,2‐addition (150 °C) and 80% 1,4‐addition (138 °C). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1216–1227, 2005 相似文献
15.
In this work, we described an easy preparation of substituted 4-amino-5-cyano-1,3-thiazoles. These compounds have been used as starting materials to obtain two classes of compounds. New substituted [1,3]thiazolo[4,5-e]pyridines were synthesized in one step via Friedländer reaction. Diazotation of 4-amino-5-cyano-1,3-thiazoles afforded 4-chloro[1,3]thiazolo[4,5-d][1,2,3]triazines in one step. The later was substituted by a secondary amine to obtain substituted 4-amino[1,3]thiazolo[4,5-d][1,2,3]triazines. 相似文献
16.
Z. Rzączyńska M. Woźniak W. Wołodkiewicz A. Ostasz S. Pikus 《Journal of Thermal Analysis and Calorimetry》2007,88(3):871-876
The complexes of yttrium(III) and lanthanides(III) with 5-amino-1,3-benzenedicarboxylic acid form two isostructural series
of compounds and have the general formula Ln2(C8H5O4N)3·nH2O, where n = 13 for Y, La-Er and n=9 for Tm, Yb, Lu. They are insoluble in water and stable at room temperature. On heating in air or inert gas atmosphere they
lose all water molecules in several steps. The anhydrous compounds are stable to about 400°C and next decompose to oxides. 相似文献
17.
A method was developed to prepare 1,3-chloroisothiocyanatoalkanes by reducing 1,3-isothiocyanato ketones using sodium borohydride at pH ~7 and subsequent treatment of the resultant 1,3-isothiocyanato alcohols with thionyl chloride. The reaction of 1,3-chloroisothiocyanatoalkanes with sodium hydrosulfide or amines gives substituted tetrahydro-1,3-thiazine-2-thiones or 2-amino-5,6-dihydro-1,3-thiazines. 相似文献
18.
NHC‐Pd complex based on 1,3‐bis (4‐ethoxycarbonylphenyl) imidazolium chloride: synthesis,structure and catalytic activity in the synthesis of axially chiral benzophenone hydrazone
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Wenzeng Duan Zhaofeng Sun Yanmin Huo Yanke Liu Guangqing Wu Ruifeng Wang Shuang Wu Qingxia Yao Shuwen Gong 《应用有机金属化学》2018,32(9)
A novel NHC–Pd complex of 1,3‐bis (4‐ethoxycarbonylphenyl) imidazolium chloride has been synthesized and characterized by 1H NMR, 13C NMR, IR and X‐ray single‐crystal diffraction studies. TG analysis shows that the NHC‐Pd complex is stable under 208 °C. The catalytic activities have been explored for the synthesis of axially chiral N‐(2′‐methoxy‐1,1′‐binaphthalen‐2‐yl) benzophenone hydrazone. The result indicates that the novel NHC‐Pd complex can achieve better catalytic activity than the Pd‐phosphine catalysts in the synthesis of axially chiral N‐(2′‐methoxy‐1,1′‐binaphthalen‐2‐yl) benzophenone hydrazone. 相似文献
19.
T. S. Safonova M. P. Nemeryuk M. M. Likhovidova A. L. Sedov A. F. Keremov N. P. Solov’eva O. S. Anisimova 《Chemistry of Heterocyclic Compounds》2005,41(4):526-535
By reaction of 4-substituted 5-amino-6-mercaptopyrimidines with 5-bromo-2,2-dimethyl-4,6-dioxo-1,3-dioxane, we have obtained 4′-substituted 5-(5-amino-6-pyrimidylthio)-2,2-dimethyl-4,6-dioxo-1,3-dioxanes. We have studied diazotization of these compounds by isoamyl nitrite. In the case of 4′-methoxy- and 4′-dimethylamino-substituted derivatives, we have obtained derivatives of novel heterocyclic systems: pyrimido[5,4-e][1,3,4]thiadiazine and pyrimido[5,4-e][1,3,4]thiadiazine-7-spiro-5′-1,3-dioxane, and in the case of the 4′-isopropylamino-substituted derivative we obtained 4-isopropyl-7-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)-1,2,3-triazolo[5,4-d]pyrimidin-7-ylidene.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 613–623, April, 2005. 相似文献