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1.
《Analytical letters》2012,45(6):517-518
Abstract

In an earlier communication we reported GC-MS studios on the reaction products of secondary amino tricyclics and dimethylformamide. 1 The diethyl acctal reaction products were identified as N-ethyl derivatives on the basis of mass spectroscopic analysis. In a follow-up study, we reported the same reaction products were formed from other DMF-dialkyl acetals, such as dimethyl and dipropyl acetals. 2 In view of this unusual reaction we reinvestigated the structure of the reaction products utilizing alternative spectroscopic methods, viz. NMR and IR, and present a correction to our earlier work ()Desipramine (1 mg) was heated with DMF-diethyl acetal (100 μ 1) at 80°C. for 15 min. The product: was dissolved in ethyl acetate (5 ml), extracted into 1 ml of 0.5 N HCl and back extracted into ethyl acetate at pH 11.0. The organic extract was dried over anhydrous sodium sulfate and evaporated to dryness under nitrogen. The resulting residue was used directly in the NMR and IR studies.  相似文献   

2.
《Analytical letters》2012,45(12):1293-1304
Abstract

We have extended our earlier work on alkylation of secondary amino compounds with dimethylformamide diethyl acetal to other alkyl acetals, such as dimethyl and dipropyl acetal. All the alkylating DMT-dialkyl acetal reagents tested gave only N-ethyl derivatives of the secondary amines. The reagent purity was tested by preparing the esters of carboxylic acids, where the appropriate alkyl (methyl or propyl) ester is obtained. It is concluded that all dimethylformamide dialkyl acetals yield a single N-ethyl derivative of secondary amine. The reaction mechanism is not understood.  相似文献   

3.
《Analytical letters》2012,45(7):625-634
Abstract

The product of the reaction of dialkyl acetals of N, N-dimethyl-formamide with desipramine has been found to be N-formyldesipramine, and not the N-ethyl derivative as reported earlier. Evidence for the structure was obtained from NMR, IR and mass spectra of the compound as well as comparison with N-formyl and N-ethyldesipramine prepared by alternate routes.  相似文献   

4.
 A rapid and practical green route for the N-formylation of amines with formic acid using Amberlite IR-120 as a catalyst is described. This method provides an efficient and much improved modification over the reported methods in terms of yield, reaction time, and work-up procedure. A wide variety of substituents is tolerated, which is not the case for existing procedures.  相似文献   

5.
JPC – Journal of Planar Chromatography – Modern TLC - TLC is an ideal technique for quantitative analysis of an ethanol-amine compound, 2-(methylamino)ethanol. A semi-quantitative TLC...  相似文献   

6.
The interaction of 3,5-bis(N,N-dimethylaminomethylene)amino-1-methyl-4-nitropyrazole with amines proceeds regioselectively with the formation of 3-amino-5-(N,N-dimethylaminomethylene)amino-1-methyl-4-nitropyrazole. Amines are converted in this way into N,N-dimethylformamidine derivatives. The structures of the compounds obtained were proved by 1H and 13C NMR spectroscopy and by X-ray crystallographic analysis.  相似文献   

7.
《Analytical letters》2012,45(7):441-448
Abstract

Primary and secondary amines react reproducibly with fluorescamine to form pyrrolinones or aminoenone type chromophores with long wavelength absorption maxima in the 375–410 and 310–320 nm regions, respectively. A simple procedure has been worked out for the simultaneous colorimetric determination of primary and secondary amines.  相似文献   

8.
应用胺类化合物与4,4'-二氟苯偶酰的亲核取代反应合成了多种对称或不对称 的4,4'-双(二烷氨基)苯偶酰。结构经元素分析,IR,~1H NMR和MS确定,其中 伯胺与4,4'-二氟苯偶酰的反应得到了一边取代、另外一边形成亚胺结构的产物, 并对此反应机理进行了探讨。  相似文献   

9.
Aerobic amine oxidation is an attractive and elegant process for the α functionalization of amines. However, there are still several mechanistic uncertainties, particularly the factors governing the regioselectivity of the oxidation of asymmetric secondary amines and the oxidation rates of mixed primary amines. Herein, it is reported that singlet‐oxygen‐mediated oxidation of 1° and 2° amines is sensitive to the strength of the α‐C?H bond and steric factors. Estimation of the relative bond dissociation energy by natural bond order analysis or by means of one‐bond C?H coupling constants allowed the regioselectivity of secondary amine oxidations to be explained and predicted. In addition, the findings were utilized to synthesize highly regioselective substrates and perform selective amine cross‐couplings to produce imines.  相似文献   

10.
朱爱芝  王燕桓  傅承光 《色谱》1997,15(5):381-383
立了一种灵敏检测仲胺的新方法。首次以丹酰氯作为仲胺的电化学检测衍生试剂,对分离检测条件、仲胺的衍生条件及电化学定量检测条件作了详细的研究。以甲醇-20mmol/L的邻苯二甲酸氢钾缓冲液(70∶30,pH3.3)为淋洗液,采用安培检测器在E=+1.1V电压条件下,在PERKIN-ELMER/HS-3C18(83mm×4.6mmi.d.,3μm)柱上实现了二甲胺、二乙胺和哌啶的良好反相分离和灵敏检测,线性范围超过两个数量级。二甲胺、二乙胺和哌啶的检出限分别为0.024,0.60,0.090pg。  相似文献   

11.
The aggregation of BuLi (LiR) in diethyl ether (Et2O) in the presence of LiBr was studied by 6Li‐ and 13C‐NMR spectroscopy. For a 1.0 : 0.8 mixture of both species, the clusters (LiR)4, Li4R3Br, Li4R2Br2, Li4RBr3, and/or Li2RBr in the ratio 7 : 81 : 12 with Li4RBr3 and/or Li2RBr<1 were detected with the isotopic fingerprint method that is based on secondary deuterium (D)‐induced isotope shifts for δ(Li). The raising content of bromide ions causes increased shielding for δ(Li). As in the case of a 1 : 1 MeLi/LiBr mixture in Et2O, cluster Li4R3Br is the most stable one. In the presence of N,N,N′,N′‐tetramethylethylenediamine (TMEDA), only a mixed dimer was found. For LiClO4, no inclusion of the ClO$\rm{{_{4}^{-}}}$ ion could be detected. A mixture BuLi/PhLi 1 : 1 in Et2O in the presence of TMEDA showed only dimers with the mixed dimer as the most stable cluster. Chemical exchange of Li between the two homodimers was detected by EXSY spectroscopy. This implies an exchange mechanism with a fluxional tetramer as intermediate.  相似文献   

12.
Abstract

A new tripodal O-donor ligand, tris(2-N,N-dibutylcarbamoylmethoxyphenyl)phosphine oxide (L), was synthesized. This potentially tetradentate ligand L exhibits variable denticity upon complexation with UO2(NO3)2, Nd(NO3)3, and Lu(NO3)3. The complexes were studied by elemental analysis, IR, and 1H, 13C, and 31P NMR spectroscopy.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.]  相似文献   

13.
X-Ray diffraction, IR and 1H NMR studies were performed on the 1:1 adduct of 1,8-bis(dimethylamino)naphthalene (DMAN) with 1,8-dihydroxy-2,4-dinitronaphthalene (DHDNN). The adduct crystallizes in the triclinic system, space group , a = 9.911(2) Å, b = 11.212(2) Å, c = 11.194(2) Å, = 68.95(2)°, β = 79.72(2)°, γ = 73.78(2)°, Z = 2. Both [NHN]+ and [OHO] hydrogen bonds formed in the ion pairs are asymmetrical with lengths equal to 2.574(2) Å and 2.466(4) Å respectively. The [NHN]+ bridge shows a typical behaviour in the IR spectrum, i.e. a low-frequency absorption between 300 and 700 cm−1. The coupling of [OHO] hydrogen bonds with the naphthalene π-electron system is so strong that no absorption related to the proton stretching vibrations can be detected in the high- and low-frequency regions. The 1H NMR chemical shifts for the [NHN]+ and [OHO] bridge protons of 18.63 and 15.81 ppm respectively confirm the strong hydrogen bonds.  相似文献   

14.
A reaction of cycloalkanone, alkanone and alkyl aryl ketone ketals with H2O2 catalyzed by boron trifluoride etherate and boron trifluoride-methanol complexes was studied. A new versatile method for the synthesis of bishydroperoxides and their derivatives, viz. 1,1′-dihydroperoxyperoxides and 1,2,4,5-tetraoxacyclohexanes, was developed based on this reaction.  相似文献   

15.
The reaction of benzaldehyde with aliphatic glycols was performed over Al-MCM-41 with various Si/Al ratios. The effects of various parameters like temperature, mole ratio, reaction time and catalyst amount on the formation of acetals were optimized. The mesoporous Al-MCM-41 (Si/Al ratio 36, 57, 81 and 108) were synthesized by hydrothermal method. The synthesized catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption isotherm (BET), thermo gravimetric-differential thermal analysis (TGA-DTA) and TEM techniques. The acidity of the catalysts was measured by pyridine adsorption followed by FT-IR analysis. TEM analysis showed that the honeycomb-like regular arrangement of hexagonal pores on the molecular sieves. The highly hydrophobic Al-MCM-41 (108) showed higher activity than the other Si/Al ratios. The activity of the catalysts showed the following order Al-MCM-41 (108) > Al-MCM-41 (81) > Al-MCM-41 (57) > Al-MCM-41 (36). The hydrophobicity and nucleophilicity of the glycols highly influences the conversion of benzaldehyde, it followed the order; hexylene glycol (HG) > propylene glycol (PG) > ethylene glycol (EG). The results showed that mole ratio of 1:3 (aldehyde:glycol) gave higher yield than the other mole ratios.  相似文献   

16.
A novel and efficient palladium‐catalyzed hydroaminocarbonylation of alkenes with aminals has been developed under mild reaction conditions, and allows the synthesis of a wide range of N‐alkyl linear amides in good yields with high regioselectivity. On the basis of this method, a cooperative catalytic system operating by the synergistic combination of palladium, paraformaldehyde, and acid was established for promoting the hydroaminocarbonylation of alkenes with both aromatic and aliphatic amines, which do not react well under conventional palladium‐catalyzed hydroaminocarbonylation.  相似文献   

17.
18.
The interaction of diethylzinc with Aerosil has been examined by IR spectroscopy and mass spectrometry. The reaction involves both free hydroxyl groups and siloxane groups of the surface resulting in the formation of Si-O-Zn-Et and Si-Et fragments. At temperatures above 300 °C, these structures undergo decomposition with the recovery of Si-OH groups on the Aerosil surface and liberation of metallic zinc.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1666–1668, September, 1994.The authors are grateful to M. B. Molotovshchikova for continuous help in performing the experiment.  相似文献   

19.
A novel synthetic method for the preparation of 5‐aryl‐7‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐2‐phenylpyrazolo[1,5‐c]‐pyrimidines and 1‐(5‐aryl‐2‐phenylpyrazolo[1,5‐c]pyrimidin‐7‐yl)‐3‐methyl‐1H‐pyrazol‐5‐ols is provided by condensative cyclization of 5‐aryl‐7‐hydrazino‐2‐phenylpyrazolo[1,5‐c]pyrimidines with 1,3‐dicarbonyl compounds. The study of the more reactive position for electrophilic substitusion reactions on such ring system was also achieved.  相似文献   

20.
3-[2-(6,6-Dimethylbicyclo[3.1.1]hept-2-en-2-yl)]-2-dimethylcarbamoyloxirane and the dimethylamide of 2-chloro-3-[2-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)]-3-(dimethyl-carbamidomethyloxy)propionic acid were obtained by the reaction of myrtenal with dimethylamide of chloroacetic acid in the presence of NaH. The structures of the compounds obtained were confirmed by NMR, IR, UV, and CD spectroscopy and mass-spectrometry.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 944–945, May, 1995.The authors express their gratitude to I. Kh. Rizvanov who recorded the mass spectrum of compound5.This work was financially supported by the Russian Foundation for Basic Research (Project No. 94-03-09586).  相似文献   

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