<i>β</i>-Oxoanilides in Heterocyclic Synthesis: Synthesis and Antimicrobial Activity of Pyridines, Pyrans, Pyrimidines and Azolo, Azinopyrimidines Incorporating Antipyrine Moiety

Condensation of β-Oxoanilide 1 with active methylene derivatives 2a,bafforded the pyridine derivative 5, and with crotononitrile afforded the pyridine 8. Compounds 9 and 11a-c were obtained by reaction of 1 with malononitrile dimer and arylidinemalononitrile 10a-10c. In contrast, when compound 1 reacted with ethoxymethylen malononitrile afforded the pyridine derivative 13. On the other hand, treatment of 1 with anthranilic acid gave the quinoline derivative 14. Also, reactions of 1 with isothiocyanate derivatives afforded compounds 16-18. The reaction of 1 with chalcone derivative afforded the pyridine derivative 22. Treatment of compound 1 with thiourea produced pyrimidine derivative 23. Furthermore, compound 1 converted into pyrimidinethione 24a and pyrimidinone 24b on treatment with a mixture of aromatic aldehydes and thiourea or urea respectively. Reaction of 24a with hydrazonyl halide, thiosemicarbazide and arylidinecyanothioacetamide afforded compounds 26, 28 and 29. Compound 29 was treated with chloroacetonitrile to afford compound 30. Six compounds from the newly synthesized were screened for antibacterial and antifungal activity against bacteria staphylococcus aureus, bacillus cereus and klebsiella pneumonia and fungi aspergillus flavus and aspergillus ochraceous, respectively. Some of the tested compounds showed significant antimicrobial activity. IR, 1H NMR, mass spectral data, and elemental analysis elucidated the structures of all the newly synthesized compounds.

One-pot three-component synthesis of tetrahydrobenzo[b]pyrans catalyzed by cost-effective ionic liquid in aqueous medium

A simple and ef ficient method is proposed for the synthesis of tetrahydrobenzo[b]pyrans with aromatic aldehydes, active methylene compounds, and dimedone using basic ionic liquid catalyst in water. The procedure offers several advantages including short reaction time, good yield, easy procedure, and good recyclability of catalysts, which may be a practical alternative to conventional processes for preparation of 4-hpyrans.

A Recyclable and Highly Effective ZnO-beta Zeolite as a Catalyst for One-pot Three-Component Synthesis of Tetrahydrobenzo[b]pyrans

4H-Benzo[b]pyrans was synthesized under reflux condition in ethanol via condensation of benzaldehyde, malononitrile and dimedone with ZnO-beta zeolite as an inexpensive and effective catalyst. The key features of the reported protocols are good to excellent yields, short reaction time and recovery and reusability of catalytic material.

H_6P_2W_(18)O_(62)á18H_2O: A green and reusable catalyst for one-pot synthesis of pyrano[4,3-b]pyrans in water

A convenient,effcient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot,three-component reaction of 4-hydroxy-6-methylpyran-2-one,aldehydes and malononitrile in water using H6P2W18O62á18H2O as catalyst.Reusability of the catalyst and reaction media,short reaction times and easy isolation of products are some added advantages of the present methodology.

Effects of Different Compounding of Formulae on Content of Gardenoside in Yin Chen Hao Decoction

In order to observe the effects of the ground and intact Zhi Zi (Fructus Gardeniae) and different combinations of the ingredients and refined single Chinese drug granules in Yin Chen Hao Decoction compound prescription on the contents of gardenoside (an effective component of the prescription), the contents of gardenoside were determined with reversed phase high performance liquid chromatography (HPLC), with acetonitrile-water (15:85) as mobile phase, at wave length 238nm. The results indicated that the gardenoside-decocted-out rates in the decoctions prepared by different combinations of the ingredients with the ground Zhi Zi (Fructus Gardeniae) all were higher significantly than those in the decoction with intact Zhi Zi (Fructus Gardeniae), and generally, different combinations of the ingredients in the decoction had only little effect on the gardenoside-decocted-out rate.

具有聚集诱导发光行为的环状多烯类分子(英文)

研究了4H-pyrans,fulvenes,siloles等环状多烯结构的小分子荧光染料在溶液,固态及薄层层析板上的荧光发射行为。与大多数传统的荧光染料小分子不同,这些多烯类荧光染料分子在稀溶液中基本没有荧光,而在聚集态下呈现非常明亮的荧光发射,同时伴随着荧光量子效率的大幅提高(聚集诱导发光)。它们在薄层层析板上也具有很强的荧光发射。但当薄层层析板暴露于有机溶剂气氛下,荧光消失,离开有机溶剂气氛,荧光恢复,这一可逆过程并可多次重复。在固体状态,它们的荧光发射与聚集态结构密切相关。通过从无定型态到结晶态以及从一种结晶态到另一种结晶态的变化,可以有效的调节它们的固体荧光发射。

纳米Ce_1Mg_xZr_(1-x)O_2固体多相催化剂的制备、表征及催化合成四氢苯并[b]吡喃衍生物的性能(英文)

A series of Ce1MgxZr1-xO2 mixed metal oxides with different molar ratios were prepared by simple co-precipitation and were characterized by X-ray diffraction,infrared spectroscopy,scanning electron microscopy,energy dispersive spectroscopy,temperature-programmed desorption of CO2,and N2 adsorption techniques.The prepared materials were tested for catalytic activity by the synthesis of tetrahydrobenzo[b]pyran derivatives using a three component reaction(aromatic aldehydes,malononitrile,and dimedone) in an ethanol medium.The best catalytic activity was obtained with Ce1Mg0.6Zr0.4O2.The particle size or crystallite size was estimated using the Debye-Scherrer equation.The addition of magnesium oxide into the ceria-zirconia lattice resulted in the formation of nanosized particles ranging from 5.41 to 9.78 nm.This work describes the catalytic behavior of magnesium oxide in mixed metal oxide systems.

硅胶键合N-丙基哌嗪n-丙酸钠作为可循环使用催化剂催化4H-吡喃衍生物合成(英文)

Silica‐bonded N‐propylpiperazine sodium n‐propionate(SBPPSP) was found to act as an efficient solid base for the preparation of a series of 4H‐benzo[b]pyran derivatives. SBPPSP was used as a recyclable heterogeneous solid base catalyst for the synthesis of 3,4‐dihydropyrano[c]chromenes, 2‐amino‐4H‐pyrans, 1,4‐dihydropyrano[2,3‐c]pyrazoles, and 2‐amino‐4H‐benzo[e]‐chromenes via the condensation reaction of dimedone, ethyl acetoacetate, 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐ one, and α‐naphthol, respectively, with aromatic aldehydes and malononitrile in refluxing aqueous ethanol. The heterogeneous solid base showed similar efficiency when reused in consecutive reactions.

An Efficient and Green Synthesis of 5-Oxo-5, 6, 7, 8-tetrahydro- 4H-benzo-[b]-pyran Derivatives Promoted by InCl_3·4H_2O Under Microwave Irradiation

A rapid and facile preparation of benzo-[b]-pyran derivatives through condensation of chalcone and 5, 5-dimethyl-1,3-cyclohexandione under microwave irradiation in the presence of catalytic amount of InCl3·4H2O has been developed. With its high efficiency, operational simplicity and environmental benignancy, this method may provide a useful alternative for the preparation of benzo-[b]-pyran derivatives.

Synthesis of fused pyran and arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methane in ionic liquid

Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis（4-hydroxy-6-methyl-2-oxo-2H-pyran-3- yl）methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-methyl-2-oxo-pyran with or without acetic anhydride. By using these novel procedures, pyrimidine nucleoside-fused pyran and arylbis（pyranon-3-yl）methane hybrids with potential biological activities were constructed.

Efficient Synthesis, Crystal Structure and Antibacterial Activity of Two Novel 1,3-Oxazin Derivatives

Two new 1,3-oxazin derivatives, C22H24N2O5 （3I） and C19H16N2O5（3II）, have been synthesized via an unusual cascade reaction. The attractive aspect of this cascade reaction is that the novel construction of 1,3-oxazine and the direct C-N bond formation from C-C bond can be easily achieved via pyridine-mediated acylation in a one-pot operation. Both compounds have been synthesized and characterized by elemental analysis, IR, NMR spectra and X-ray single-crystal diffraction. Compound 3I crystallizes in monoclinic, space group P21/n with α = 16.282（4）, b = 7.4117（18）, c = 17.256（5） A, β = 103.193（9）°, V = 2027.4（9） A3, Mr = 396.43, Z = 4, Dc= 1.299 g/cm3, F（000） = 840, MoKa radiation （λ = 0.71073 A）, the final R = 0.0771 and wR = 0.1582 for 3662 were observed reflections with I 〉 2σ（I）. Compound 3II crystallizes in triclinic, space group Pī with α = 7.1265（9）, b = 10.1071（13）, c = 23.529（3） A, α = 97.463（9）, β = 96.981（9）, γ = 94.345（9）°, V = 1600.5（4） A3, Z = 4, Dc = 1.409 g/cm3, F（000） = 736, CuKa radiation （λ = 1.54186 A）, the final R = 0.0515 and wR = 0.1241 for 4920 observed reflections with I 〉 2σ（I）. The preliminary antibacterial activities of 2 and 3 against E. coli and S. aureuswere investigated. The results showed that the inhibiting effect of 3 was higher than that of 2.

浅析非掺杂超薄层DCJTB的位置对有机电致发光器件性能的影响

1前言在OLEDs显示的市场上,人们普遍把红色荧光染料4-（dicyanomethylene）-2-t-butyl-6（1,1,7,7-tetramethyljulolidyl-9-enyl）-4H-pyran（DCJTB）作为客体掺杂材料,尽管DCJTB是很好的红色荧光染料,它的发光波长为620nm,并且量子效率可达到90%,理想的掺杂方式是将它掺杂在tris（8-quinolinolato）-aluminum（AlQ）中,呈现橙红色的光。

Electronic Transport Properties of a Naphthopyran-Based Optical Molecular Switch: an ab initio Study

The electronic transport properties of a naphthopyran-based molecular optical switch are investigated by using the nonequilibrium Green's function formalism combined with first-principles density functional theory.The molecule that comprises the switch can convert between its open and closed forms upon photoexcitation.Theoretical results show that the current through the open form is significantly larger than that through the closed form,which is different from other optical switches based on ring-opening reactions of the molecular bridge.The maximum on-off ratio(about 90)can be obtained at 1.4 V.The physical origin of the switching behavior is interpreted based on the spatial distributions of molecular orbitals and the HOMO-LUMO gap.Our result shows that the naphthopyran-based molecule is a good candidate for optical molecular switches and will be useful in the near future.

New Practical Synthesis of Tetrahydronquinolin-2,5-diones

A series of 4,6,7,8-tetrahydro-2,5-（1H,3H）-quinolinediones was prepared from ethyl-2-cyanoacetate, aromatic aldehydes and 1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione by two steps, the yields were moderate to excellent. This method is a new practical promising green strategy to synthesize tetrahydronquinolin-2,5-diones.

Crystal Structure of 2-Amino-5,10-dioxo-4-aryl-5,10-dihydro-4H-naphtho [2,3-b]pyran-3-carboxylic Acid Ethyl Ester

The title compounds have been synthesized via a three-component reaction and their structures were characterized by IR, ^1H NMR, ^13C NMR and X-ray single-crystal diffraction. The crystal of compound 4a belongs to monoclinic, space group P121/c1 with a = 8.575（3）, b = 9.590（3）, c = 21.431（6）A, β = 91.172（3）°, V = 1762.1（9）A^3, Mr = 393.36, Z = 4, Dc= 1.483 g/cm^3, μ（MoKα） = 0.113 mm^-1, F（000） = 816, the final R = 0.0366 and wR = 0.0941. The crystal of compound 4b is of triclinic, space group P-1 with a = 8.6420（17）, b = 9.761（2）, c = 11.132（2） A, α = 97.51（3）, β = 97.86（3）, γ = 92.85（3）°, V = 920.1（3） A^3, Mr = 393.36, Z = 2, Dc = 1.420 g/cm^3, μ（MoKα） = 0.108 mm^-1, F（000） = 408, the final R = 0.0612 and wR = 0.1781. In each molecular structure, the naphthalene rings and pyran rings are almost coplanar with the latter in an envelope conformation. The rings formed by the N-H…O intramolecular hydrogen bonds are almost planar in these compounds. Their crystal packing is stabilized by intermolecular hydrogen bonds together with C-H…π and π-π stacking interactions.

Ytterbium triflate hydrate catalyzed Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds

Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.

An Eco-friendly Method for Novel Scaffolds： Novel N2-Substituted Fused Pyrazolo （4＇,3＇：5,6） Pyrano （2,3-d） Pyrimidine Terminated by Hydroxy Group

Four components have been reacted in water and in the presence of N-morpholine yielded pyrnopyrazole as a simple substrate for novel N2-acyclonucleoside derivatives of fused pyranopyrazole. The sodium salt of fused pyranopyrazole reacted with halo alcohols led to the formation of new scaffolds from fused pyranopyrazole derivatives. All newly prepared compounds are characterized spectroscopically.

Palladium (0) Nanoparticles: A Novel and Reusable Catalyst for the Synthesis of Various Pyran Derivatives

A ligand free, Palladium nanoparticles catalyzed synthesis of pyran derivatives using C-H activated compound, malononitrile and aryl aldehyde via Knoevenagel condensation followed by Michael addition reaction using Palladium nanoparticles as catalyst in one-pot is described herein. The advantages of this method lie in its simplicity, low catalyst loading, cost effectiveness and easy to handle. The Palladium Nanoparticles can be reused without loss of activity even after recycling four times. The palladium nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM). The present method also allows us to synthesize highly functionalized title compounds from simple and readily available inputs.

Synthesis and Antibacterial Activities of Pyran Annulated Heterocyclic Compounds

Two novel pyran annulated heterocyclic compounds （1 and 2） were synthesized and characterized via IR, lH NMR and H RMS. The structure of compound 1 was verified by single-crystal X-ray diffraction. The in vitro antibacterial activities of the two compounds against Staphylococcus aureus （S. aureus ATCC 29213）, methicillin-resistant S. aureus （MRSA XJ 75302）, vancomycin-intermediate S. aureus （Mu50 ATCC 700699）, and USA 300 （Los Angeles County clone, LAC） were evaluated by observing the minimum inhibitory concentration.

Multimodal 4-arylchromene derivatives with microtubule-destabilizing,anti-angiogenic,and MYB-inhibitory activities

Aim:Efficient and readily available anticancer drugs are sought as treatment options.For this reason,chromene derivatives were prepared using the one-pot reaction and tested for their anticancer and anti-angiogenic properties.Methods:2-Amino-3-cyano-4-(aryl)-7-methoxy-4H-chromene compounds(2A-R)were repurposed or newly synthesized via a three-component reaction of 3-methoxyphenol,various aryl aldehydes,and malononitrile.We performed assays to study the inhibition of tumor cell growth[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromid(MTT)assay],effects on microtubules(immunofluorescence),cell cycle(flow-activated cell sorting analysis),angiogenesis(zebrafish model),and MYB activity(luciferase reporter assay).Fluorescence microscopy was applied for localization studies via copper-catalyzed azide-alkyne click reaction of an alkyne-tagged drug derivative.Results:Compounds 2A-C and 2F exhibited robust antiproliferative activities against several human cancer cell lines(50%inhibitory concentrations in the low nanomolar range)and showed potent MYB inhibition.The alkyne derivative 3 was localized in the cytoplasm after only 10 min of incubation.Substantial microtubule disruption and G2/M cell-cycle arrest were observed,where compound 2F stood out as a promising microtubule-disrupting agent.The study of anti-angiogenic properties showed that 2A was the only candidate with a high potential to inhibit blood vessel formation in vivo.Conclusion:The close interplay of various mechanisms,including cell-cycle arrest,MYB inhibition,and anti-angiogenic activity,led to identifying promising multimodal anticancer drug candidates.