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1.
In this research, it was displayed an efficient method for the one-pot reaction of cyclohexanone, benzaldehyde and malononitrile for the synthesis of 4H-chromenes by using CoFe2O4/lamellar mesopore silica anchored to melamine as a magnetic nanocatalyst. This nanocatalyst was prepared in several steps and discriminated by XRD, FT-IR, SEM, VSM, TGA and BET techniques. The catalyst has a large active base site that has functionalized in both the surface and the pore of nanostructure. The advantages of magnetic nanocatalyst were simple accessible, heterogeneous nanocatalyst, easy work up and reusability. The various derivatives of 4H-chromenes were synthesized in the presence of CoFe2O4/lamellar mesopore silica/melamine magnetic nanocatalyst with the excellent yields and appropriate times. The products were identified by the melting point, FT-IR, 1H NMR, 13C NMR and C.H.N techniques.  相似文献   

2.
Summary Cobalt(II) complexes of the four 2-aminopicolineN-oxides and 2-amino-4, 6-lutidineN-oxide were prepared from Co(BF4)2 and CoCl2, and characterized by partial elemental analyses, magnetic moments, molar conductivities, thermal analyses, and by plasma desorption mass, i.r., electronic, and e.s.r. spectroscopy. The compounds derived from CoCl2 are 4-coordinate, tetrahedral, molecular solids with CoO2Cl2 chromophores. Dq values range from 332 to 382 cm–1 and those of B from 758 to 813 cm–1 for the five solids. Three of the compounds prepared from Co(BF4)2 are octahedral with the following stoichiometry: [CoL6](BF4)2 where L=2-amino-4-picolineN-oxide and [CoL5(H2O)] (BF4)2 where L is either 2-amino-3-or 2-amino-5-picolineN-oxide. Both 2-amino-6-picolineN-oxide and 2-amino-4, 6-lutidineN-oxide gave square planar [CoL 4 2+ ] complex ions. While numerous square planar cobalt(II) centers are known, those described here are probably the first examples with monodentate ligands and a CoO4 center. They have weak e.s.r. spectra, magnetic moments between 2 and 3 BM and characteristic d-d spectra.  相似文献   

3.
Russian Journal of General Chemistry - A highly efficient one-pot three-component synthesis of 2-amino-3-cyano-4H-chromenes has been developed by annulation of aldehydes, malononitrile and dimedone...  相似文献   

4.
Reaction of CoX2 · nH2O with either 2-amino-3-methylpyridine (3-MAP) or 2-amino-5-methylpyridine (5-MAP) in aqueous acid gave complexes, (3-MAPH)2CoX4 or (5-MAPH)2CoX4 (H2O) n [n = 0,1; X = Cl, Br; 3-MAPH = 2-amino-3-methylpyridinium, 5-MAPH = 2-amino-5-methylpyridinium]. The 3-MAPH salts are formed in the triclinic crystal system while the 5-MAPH salts are formed in the monoclinic crystal system. Three of these compounds exhibit weak antiferromagnetic interactions along with varying degrees of single-ion anisotropy, however, 1 shows easy-plane anisotropy and exhibits a mixture of ferromagnetic and antiferromagnetic interactions.  相似文献   

5.
Diabatic photoinduced ring opening of the chromene ring of 2-amino-5,6-benzo-2H-chromenes and 2-amino-6-methyl-7,8-benzo-2H-chromenes leads, in the same way as a thermally induced reaction, to the establishment of ring-chain tautomer equilibrium in the ground electronic state, the position of this equilibrium depending on the polarity of the solvent, the temperature, and structural factors. o-Quinoid tautomers exist as several stable isomeric forms: an acoplanar cis-S-cis-trans-form absorbing in the shortwave region, and S-trans-isomers absorbing in the longwave region of the spectrum. Photoexcitation of the o-quinoid forms in the temperature range 125–190 K initiates mutual conversions of these and the initial 2H-chromene structure. The relative stability of the conformers of the o-quinoid form depends on steric and electronic factors: benzanellation in positions 5,6 leads to stabilization of the cis-S-cis-trans-isomer and in positions 7,8 the S-trans-isomers are more preferred: -acceptor substituents on the amine component increase the stability of the cis-S-cis-trans isomer and electron-donor substituents stabilize the S-trans-isomer.Communication 20 from the series Photo- and thermochromic piranes. See [1] for Communication 19.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 453–458, April, 1991.  相似文献   

6.
A three-component cascade reaction of salicylaldehyde, malononitrile/cyanoacetate and nitromethane catalysed by chiral tertiary amino-thioureas was developed, which leads to the production of highly functionalized 2-amino-4H-chromenes in good yields with good to excellent enantioselectivities.  相似文献   

7.
Research on Chemical Intermediates - 1,5,7-Triazabicyclo-[4,4,0]-dec-1-ene functionalized mesoporous silica nanoparticle promoted one-pot multicomponent synthesis of 2-amino-4H-chromenes from a...  相似文献   

8.
The compound [3,5-dibromo-2-amino-4,6-dimethylpyridinium]2CuCl4, (1), was prepared from acidic hydrochloric acetonitrilic medium containing CuCl2 and 3,5-dibromo-2-amino-4,6-dimethylpyridinium bromide while [3,5-dibromo-2-amino-4,6-dimethylpyridinium]2CuBr4, (2), from acidic HBr/Br2 ethanolic medium containing 4,6-dimethylpyridine and CuBr2. The ring got dibrominated at 3 and 5 positions in situ. Single-crystal X-ray diffraction proved the compounds to be isomorphous in P − 1. A systematic study of the crystallographic parameters in dibrominated and nonbrominated 2-amino-4,6-dimethylpyridine salts will explain the role of nonclassical noncovalent interaction between aryl bromine and ionic metal bromide in the control of structure.  相似文献   

9.
Abstract

21P and 19C NMR spectroscopy is applied to study the reaction of the K2PdCl4 with 3-amino-3-phosphono- -propionic acid(α-PAsp), 2-amino-3-phosphonopropionic acid(β-Pasp). 4-amino-4-phosphonobutyric acid(α-PGlut) and 2-amino-4-phosphonobutyric acid(γ-PGlut) in a wide PH range.  相似文献   

10.
The structures of 2-amino-5-methyl-1,3,4-thia­diazo­le, C3H5N3S, and 2-amino-5-ethyl-1,3,4-thia­diazo­le, C4H7N3S, have been determined for comparison with unsubstituted 2-amino-1,3,4-thia­diazo­le. Despite their different space groups (P21/n and Pbca, respectively), the packing modes of the methyl and ethyl derivatives are similar, with comparable three-dimensional hydrogen-bonding associations. This is in contrast to the hydrogen-bonding network in 2-amino-1,3,4-thia­diazo­le, which is one-dimensional and has denser packing. It is shown that both packing forms are different polymorphs of a specific subunit of each array.  相似文献   

11.
Chen W  Cai Y  Fu X  Liu X  Lin L  Feng X 《Organic letters》2011,13(18):4910-4913
An enantioselective one-pot synthesis of 2-amino-4-(indol-3-yl)-4H-chromenes via a Knoevenagel/Pinner/Friedel-Crafts reaction of salicylaldehyde, malononitrile, and indole is presented. Moderate to good yields (up to 89%) and high enantioselectivities (up to 90% ee) were obtained with an N,N'-dioxide-Zn(II) complex as the catalyst. This strategy provides an efficient and convenient method to access enantiomerically enriched 2-amino-4H-chromene derivatives.  相似文献   

12.
Treatment of 2-hydroxybenzaldehydes by potassium t-butoxide in THF at 0°C, followed by addition of β-nitroenones 1 affords 2-acyl-2-alkyl-4-hydroxy-3-nitrochromanes 3. Subsequent treatment of these nitro alcohols by silica gel at 50°C leads to the desired 2-acyl-2-alkyl-3-nitro-2H-chromenes 4 in good yields.  相似文献   

13.
Three methods for the synthesis of various substituted 2-amino-1-pyrrolines are described:
  1. Cyclization of 2.2-disubstituted 4-bromobutyronitriles with ammonia to yield 3.3-disubstituted 2-amino-1-pyrrolines.
  2. Reduction of 2-aminopyrrolin-5-ones or 2-iminosuccinimides with LiAlH4, a route leading especially to 3.3.4-substituted 2-aminopyrrolines.
  3. Chlorination of 4.4-disubstituted pyrrolidones with POCl3 followed by treatment with NH3 gives 4.4-disubstituted 2-amino-1-pyrrolines.
  相似文献   

14.
Among a wide variety of synthetic routes to pterocarpan prototypes, a mild approach uses a reaction known as Heck oxyarylation. This method involves a reaction between 2H-chromenes and 2-chloromercuriophenols in the presence of Li2PdCl4. __________ Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 311–312, July–August, 2005.  相似文献   

15.
Summary The synthesis and characterisation of products obtained by the interaction between [Ir(NO)(MeCN)2(PPh3)2]2+ and 2-aminophenol derivatives are reported. Tetracoordinate d8complexes of the type Ir(NO)(2-ap)(PPh3) and pentacoordinate d complexes6of the type [Ir(2-ap)(PPh3)3]+ where 2-ap=2-aminophenol, 2-amino-4-nitrophenol, 2-amino-5-methylphenol, 2-3-aminonaphthol and 2-amino-4-methylphenol are obtained. The Ir(NO)(PPh3)3 complex is always present as a byproduct. Physical properties, i.r. spectra and conductivity data of the complexes are tabulated. Reaction schemes for the formation of the three complexes are proposed and discussed.  相似文献   

16.
An analysis of the PMR spectra of 2H, 6H-2, 6-dimethyl-4-amino-1,3,5-dithiazine, its acyl derivatives, and 2H, 3H, 6H-2, 6-dimethyl-4-amino-1,3,5-thiadiazine in various solvents and in the presence of Eu(FOD)3 [tris(1,1,1,2,2,3,3-heptafluoro-7,7-dimettyl-4,6-octanedionato)3 europium] confirms the structure assigned to it and makes it possible to prefer a cis orientation of the methyl substituents in the half-chair conformation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 485–487, April, 1981.  相似文献   

17.
The organic material of 2-amino-4-picolinium 4-aminobenzoate (C6H9N2+·C7H6NO2?) was synthesized and grown as single crystals at room temperature by slow evaporation solution growth technique in the constant temperature bath (±0.01 °C) using ethanol as solvent. The grown crystals were characterized by XRD and FT-IR spectral analyses. The melting point, density, UV–visible spectral studies were carried out for the grown crystals. The theoretical factor group analysis predicts 372 internal modes of vibration and optical modes in the grown title compound. The second harmonic generation (SHG) output of 2-amino-4-picolinium 4-aminobenzoate was recorded by Kurtz–Perry powder technique and it is found to be 355 mV at a given pulse energy of 1.45 mJ/s and for urea the SHG output was 525 mV. The dielectric behaviour of 2-amino-4-picolinium 4-aminobenzoate was investigated with different frequencies and temperatures.  相似文献   

18.
Four different types of new ligands Ar[COC(NOH)R] n (Ar=biphenyl, n = 1 H2L1; Ar=biphenyl, n = 2 H4L2; Ar=diphenylmethane, n = 1 H2L3; Ar=diphenylmethane, n = 2 H4L4; R=2-amino-4-chlorophenol in all ligands) have been obtained from 1 equivalent of chloroketooximes Ar[COC(NOH)Cl] n (HL1-H2L4) and 1 equivalent of 2-amino-4-chlorophenol (for H2L1 and H2L3) or 2 equivalent of 2-amino-4-chlorophenol (for H4L2 and H4L4). (Mononuclear or binuclear cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized with these ligands.) These compounds have been characterized by elemental analyses, AAS, infra-red spectra and magnetic susceptibility measurements. The ligands have been further characterized by 1H NMR. The results suggest that the dinuclear complexes of H2L1 and H2L3 have a metal:ligand ratio of 1:2; the mononuclear complexes of H4L2 and H4L4 have a metal:ligand ratio of 1:1 and dinuclear complexes H4L2 and H4L4 have a metal:ligand ratio of 2:1. The binding properties of the ligands towards selected transition metal ions (MnII, CoII, NiII, CuII, ZnII, PbII, CdII, HgII) have been established by extraction experiments. The ligands show strong binding ability towards mercury(II) ion. In addition, the thermal decomposition of some complexes is studied in nitrogen atmosphere.  相似文献   

19.
2,2-Dimethyl-4-methoxychromans (112) have been converted into 2,2-dimethyl-2H-chromenes (1324) in acidic media.  相似文献   

20.
《Tetrahedron: Asymmetry》2003,14(13):1837-1845
The highly stereoselective synthesis of (1S,2S)-2-amino-1-hydroxyalkylphosphonic acids was achieved by addition of dimethyl phosphite to N-protected aminoaldehydes. Relative configuration and solution conformations of (1S,2S)-2-amino-1-hydroxy-alkylphosphonic acids (in D2O) and their dimethyl esters (in CDCl3 and CD3OD) were established by means of NMR basing on the dependence between observed values of coupling constants (3JHH, 3JPC, 3JHP) and corresponding dihedral angles. Potentiometric and spectroscopic methods were used for the evaluation of the structure of the complexes of (1S,2S)-2-amino-1-hydroxy-alkylphosphonic acids with Zn(II) and Cu(II) ions in aqueous solutions.  相似文献   

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