首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Catalytic aminomethylation of pyrrole and indole with N,N,N′,N′-tetramethylmethanediamine in the presence of 5 mol % of ZrOCl2·8H2O proceeds selectively at the positions 2, 5 of pyrrole and 1, 3 of indole. Carbazole under the same conditions affords 3-formyl-9-aminomethyl derivative. The reaction in the presence of 5 mol % of K2CO3 occurs as monoaminomethylation: for pyrrole at the position 2, for indole at the position 3, and for carbazole at the nitrogen atom of the substrate. Water-soluble 1,1′-(1H-pyrrole-2,5-diyl)bis(N,N-dimethylmethanamine) exhibits a fungistatic activity with respect to phytopathogenic fungi Rhizoctonia solani.  相似文献   

3.
The reaction of N,N,N′,N′-tetramethylmethanediamine with pheophorbide a methyl ester gave the corresponding 13″-dimethylaminomethyl derivative and 13-N,N-dimethylamide derivative of chlorin e 6 having a methyl acrylate moiety in the 15-position. Conditions were found for the synthesis of the latter both directly from pheophorbide a methyl ester and from its aminomethylation product. Probable mechanisms of the examined reactions were proposed.  相似文献   

4.
A new extractant for copper(ii) extraction, viz., N′,N′-dibutyloctanohydrazide, was synthesized. Its acid-base, extraction, and complexation properties were studied. The introduction of two butyl substituents into the hydrazide group weakens the acidic properties of the compound synthesized compared to the unsubstituted hydrazide, shifts the region of efficient copper(ii) extraction from an acidic medium to weakly acidic and ammonia media, and forms an uncharged extractive copper complex. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 380–384, February, 2008.  相似文献   

5.
The effect of N′,N′-dialkylhydrazides of aliphatic carboxylic acids of the general formula C4H9CH(C2H5)C(O)NHN(R)2 on the corrosion behavior of St.20 steel in 0.1 and 1 M HCl was studied by electrochemical and gravimetric methods.  相似文献   

6.
The structure of bis(N,N,N′,N′-tetramethylthiophosphoramidoyl)-methylamine 1 has been determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic system, with a space group P21/c, a = 11.836(2) Å, b = 11.659(2) Å, c = 12.796(5) Å and β = 95.28(3)°, V = 1758.3(5) Å3 and Z = 4. The X-ray crystallographic data have been assessed by semi-empirical and ab-initio density functional theory and by Hartree–Fock molecular orbital methods. A comparative study of the results of the different methods is given.  相似文献   

7.
Electron ionization (EI), chemical ionization (CI), tandem mass spectrometry, high-resolution measurements, and labeling studies as well as quantum chemical calculations were used to understand the behavior of the molecular radical cations (EI) and protonated molecules (CI) of substituted N-(ortho-cyclopropylphenyl)-N'-aryl ureas and N-(ortho-cyclopropylphenyl)-N'-aryl thioureas in a mass spectrometer. Fragmentation schemes and possible mechanisms of primary isomerization were proposed. According to the fragmentation pattern, formation of the corresponding benzoxazines and benzothiazines was considered as the major process of isomerization of the original M(+.) and MH(+), although some portions of these ions definitely transformed into other structures. The treatment of N-(ortho-cyclopropylphenyl)-N'-phenyl urea and N-(ortho-cyclopropylphenyl)-N'-phenylthiourea in solution with strong acids formed predicted 4-ethyl-N-phenyl-4H-3,1-benzoxazin-2-amin and 4-ethyl-N-phenyl-4H-3,1-benzothiazin-2-amine as principal products.  相似文献   

8.
Abstract  A new compound was isolated from the reaction mixture after O-demethylation of 6-O-acetyl-10α-acetoxycodeine with boron tribromide. The structure of this compound, 10α-hydroxy-β-isomorphine, was elucidated by spectral data, and its spatial arrangement was deduced from an NOE experiment. Capillary zone electrophoresis was used for separation of morphine and its 10-hydroxy analogues. Graphical abstract     相似文献   

9.
A preparation method was developed for previously unknown tetrazole derivatives containing in the 1, 2, and/or 5 positions of the tetrazole ring N-methyldiazene-N-oxide-N′-oxymethyl groups.  相似文献   

10.
The CoLX2 complexes were obtained by the reaction of N,N-dimethyl-N′,N′-dimethylthio-carbamoylsulfenamide (L) with CoX2 (X = Cl, Br, I, NCS). The complexes were investigated by elemental and X-ray analysis, IR, 1H NMR, and electron spectroscopy, conductometry, magnetochemistry, thermogravimetry. It is found that these compounds are high-spin complexes of pseudotetraedral structure with bidentate coordination of L through the thione sulfur atom and sulfenamide nitrogen atom.  相似文献   

11.
12.
Copper(II) complexing with N′,N′-diethylbenzohydrazide (DEBH) in aqueous isopropanol was studied. The formation of cationic complexes with the ratio [Cu2+]: [DEBH] = 1: 1 and 1: 2 in week acid solution and an uncharged complex with the ratio [Cu2+]: [DEBH] = 1: 2 in neutral and alkaline solutions was established. Their stability constants K st were determined. The complexes were isolated in a solid state and characterized by IR spectroscopy and elemental analysis for copper.  相似文献   

13.
The thermal effects of the neutralization of betainic protons of trimethylenediamine-N,N,N′,N′-tetraacetic acid (H4L) at 298.15 K and ionic strength of 0.3, 0.5, and 1.0 (KNO3) were directly measured by calorimetry. The standard thermodynamic characteristics of the protolytic equilibria of H4L were calculated from a combination of thermochemical and potentiometric data obtained under identical experimental conditions. The results obtained were compared with the corresponding data for related compounds taking into account the specific structure of diamine complexones.  相似文献   

14.
RHF/6-31G(d) and MP2/6-31G(d) quantum-chemical calculations of N′,N′-dimethylethanohydrazide molecule and also MP2/6-31G(d) calculations of its protonated forms were performed. With the use of IR and 1H NMR spectroscopy the series of N′,N′-dialkylhydrazides and their salts with HCl and H2SO4 were studied. The position of proton addition was determined. The experimental results were compared with the calculated findings.  相似文献   

15.
A new procedure has been developed for aminomethylation of terminal acetylenes with N,N,N′,N′-tetramethylmethanediamine in the presence of transition metals and lanthanide complexes and salts. The procedure ensures formation of the corresponding N,N-dimethylprop-2-yn-1-amines with high yield and selectivity.  相似文献   

16.
The n-decane–n-hexadecane–cyclododecane, n-decane–cyclododecane, and n-hexadecane–cyclododecane systems are studied by means of low-temperature differential thermal analysis using a differential scanning heat flow calorimeter. It is noted that all studied systems belong to the eutectic type. It is concluded that in the n-decane–n-hexadecane–cyclododecane system, the eutectic composition contains 85.0 wt % n10Н22, 4.0 wt % n16Н34, and 11.0 wt % С12Н24. It has a melting point of ?35.0°C.  相似文献   

17.
The crystalline modifications and of polypropylene (PP) were studied by using polarized light microscopy (PLM), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC). Typically crystals surrounded by spherulites were observed at low temperature. With increasing temperature the crystals melted and a new crystal appeared. More interestingly, the melting temperature of the new crystal was about 5 ° higher than that of spherulites originally present in the sample formed isothermally. It was assumed that this new crystal was the recrystalline crystal. This assumption was supported by the DSC results. Furthermore, the crystallization kinetics of the PP used was studied on the basis of the traditional Avrami analysis. As a result, the Avrami exponents of crystallization temperature from 120 to 130 °C ranged between 4.21 and 3.60, indicating that the crystallization mechanism of PP order melt was spherulitic growth and random nucleation.  相似文献   

18.
The synthesis, IR spectroscopic study, and X-ray diffraction analysis (CIF file CCDC no. 1574078) are carried out for 1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (I). The structural units of a crystal of compound I are (H4.5HPdta)0.5– anions, (H5.5HPdta)0.5+ cations, and molecules of water of crystallization joined by a branched network of hydrogen bonds: strong intermolecular O–H…O and intramolecular N–H…O bonds.  相似文献   

19.
The applicability of the Encounter Theory (ET) (the prototype of the Collision Theory) concepts for widely occurring diffusion assisted irreversible bulk reaction ABC (for example, radical reaction) in dilute solutions taking account of initial microscopic correlations and force interactions between reactants has been treated theoretically with modern many-particle method for the derivation of non-Markovian binary kinetic equations. The method shows that taking into consideration initial correlations and force interactions leads to the redefinition of the Markovian rate constant only in the expressions derived earlier. Thus, just as in the reaction AAC and the reaction ABC neglecting force and initial correlations, the Modified Encounter Theory (MET), when reduced to equations of a Regular Form, both extends the time applicability range of ET homogeneous rate equation, and yields the inhomogeneous equation of the Generalized Encounter Theory (GET). It reveals macroscopic correlations induced by the encounters in the reservoir of free walks in full agreement with physical considerations. Time accumulation of macroscopic correlations obeys the same time law as in the previously considered case neglecting force interactions. Just the rate of the process will change, according to traditional redefinition of the steady-state constant of the reaction.  相似文献   

20.
The microstructure of polystyrene, poly(methyl acrylate), and poly(tert-butyl acrylate) obtained in the presence of tri-n-butylboron in combination with naphthoquinone-1,4 and 2,3-dimethylbenzoquinone is studied. The stereoregularity of polymers formed under these conditions may be described in the framework of the first-order Markov chain model. The use of p-quinones in combination with tri-n-butylboron favors an increase in the content of isotactic triads in the polymers. The causes of the observed deviations are discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号