Ultrasound promoted greener synthesis of spiro[indole-3,5′-[1,3]oxathiolanes in water

An aqueous mediated novel synthesis of substituted 2′amino-4′benzoyl-2′-methyl spiro[indole 3,5′-[1,3]oxathiolane]-2(1H)-ones (2a–f) was carried out from the reaction of spiro [indole-3,2′-oxiranes] (1a–f) with thioacetamide in the presence of LiBr as catalyst. The reaction was carried out under both microwaves and sonication and results were also compared with conventional method. In general, improvement in rate and yields observed when reaction was carried out under sonication as compared to microwave irradiation and conventional method.     

The microwave spectrum of the C3 sugars: glyceraldehyde and 1,3-dihydroxy-2-propanone and the dehydration product 2-hydroxy-2-propen-1-al

The triose sugars with empirical formula, C₃H₆O₃, consist of the aldehyde form, glyceraldehyde, and the ketone form, 1,3-dihydroxy-2-propanone. Recently, the simplest sugar, glycolaldehyde (CH₂OHCHO) was identified in the Sgr B2(N) molecular cloud by Hollis et al. (Astrophys. J. (Lett.) 540 (2000) L107), providing the incentive to pursue the present study. The microwave spectra of the triose sugars were obtained with the NIST Fourier-transform pulsed-nozzle microwave spectrometers equipped with heated nozzles. A few tenths of a gram of solid sample was placed in the nozzle base, which was heated to between 105 and 135 °C and pressurized with inert carrier gas. Broad spectral survey scans were carried out from 10 to 20 GHz for samples of both compounds. In the glyceraldehyde sample study, three conformers of the parent species were identified as well as 1,3-dihydroxy-2-propanone. In addition, three decomposition products were also identified: formic acid, trans-methyl glyoxal, and a previously experimentally unknown compound: 2-hydroxy-2-propen-1-al. Ab initio calculations were carried out with the Gaussian 98 program at the MP2/6-311++G** level to aid in the identification of each of the new species. The survey scan of the 1,3-dihydroxy-2-propanone sample confirmed the identification of this species initially assigned in the glyceraldehyde study. The 1,3-dihydroxy-2-propanone survey also exhibited spectra from the same three decomposition products initially observed in the glyceraldehyde work. However, the three conformers of glyceraldehyde were not present in the spectra of 1,3-dihydroxy-2-propanone.     

A diversity-oriented synthesis of pyrazolo[4,3-<Emphasis Type="Italic">f</Emphasis>]quinoline derivatives with potential bioactivities via microwave-assisted multi-component reactions

Six new series of pyrazolo[4,3-f]quinoline derivatives with potential bioactivities were synthesized by the three-component reactions of aromatic aldehydes, 5-aminoindazole, and various cyclic 1,3-dicarbonyl compounds under microwave irradiation. This protocol has the valuable features of structural diversity of products, broader substrate scope, operational simplicity, high yields, and short reaction time. Moreover, the structure of compound 88a was confirmed by an X-ray crystallographic analysis and attested to the chemoselectivity of reaction where 1-methyl barbituric acid participated.     

FTIR Spectral Study of Intramolecular Hydrogen Bonding in Thromboxane A2 Receptor Antagonist S-145 and Related Compounds. Part 4

Abstract

An N-methylated compound of S-145, (±)-(5Z)-7-[3-endo-[N-methyl)phenylsulphonyl)amino]bicyclo [2.2.1]hept-2-exo-yl]heptenoic acid 1, its chain analogue 12-[N-methyl(phenylsulphonyl)amino]dodecanoic acid 3, (±)-(5Z)-7-[3-endo-(benzoylamino)bicyclo[2.2.1]hept-2-exo-yl] heptenoic acid 5 and related compounds were synthesized in order to study the formation of a new class of intramolecular hydrogen bond IX (cis-CO₂H…O = Y). Their FTIR spectra were measured in dilute CCl₄ solution and subjected to curve analysis in order to separate overlapping absorption bands. For compounds 1,3 and 5, the intramolecular hydrogen bonds of the IX type involving 14-, 17- and 14-membered rings were found between a carboxyl group, which takes a cis-structure IV, and an oxygen atom of a sulphonyl or benzoylamino group, respectively. The C[dbnd]O stretching vibration bands of these carboxyl groups shifted to lower wavenumbers (ca. 19 cm^?1). The direction of these shifts was contrary to that found for α-keto and α-alkoxycarboxylic acids in which carboxyl groups take a trans-structure III due to the formation of intramolecular hydrogen bonds I and II, respectively.     

Synthesis and Characterization of Molecules Containing Thiazole and Oxazole Moieties and Study of ESIPT Phenomenon

Two novel ESIPT molecules, 2-[4-(1,3-benzothiazol-2-yl)naphtho[1,2-d][1,3]oxazol-2-yl]phenol 9a and 4-[4-(1,3-benzothiazol-2-yl)naphtho[1,2-d][1,3]oxazol-2-yl]benzene-1,3-diol 9b were synthesized by condensing 1-amino-3-(1,3-benzothiazol-2-yl)naphthalen-2-ol with 2-hydroxybenzoic acid and 2,4-dihydroxybenzoic acid respectively. The novel compounds were characterized by FT-IR, (1)H NMR, Mass spectral and elemental analysis. Effect of polarity on photo physical properties, absorption and emission were studied. Compounds showed single absorption and dual emission due to ESIPT phenomenon. The structural changes due to ESIPT phenomenon in terms of bond angle, bond distances and geometry were investigated by using Gaussian 03 software. These two novel ESIPT molecules are thermally stable up to 200?°C.     

Ultrasonics promoted synthesis of thiazolidinones from 2-aminopyridine and 2-picolilamine

The efficient multicomponent synthesis of thiazolidinones from the reaction of arenealdehydes, mercaptoacetic acid and 2-picolilamine or 2-aminopyridine under ultrasound irradiation are reported. The reaction with 2-aminopyridine needs a Lewis acid catalysis to afford the corresponding 2-aryl-3-(pyridin-2-yl)-1,3-thiazolidin-4-ones. All novel compounds were identified and characterized by (1)H and (13)C NMR spectra. Applying the sonochemical methodology, two series of heterocyclic thiazolidinones were synthesized in good yields after short reaction times.     

Mass Spectrometry of Some Benzylidene Imidazolidinediones and Thiazolidinediones. II- chlorobenzyl imidazolidinedione and Fluoro or Chlorobenzyl Thiazolidinedione Compounds

In the present investigation, a study of the electron impact mass spectrometry data is reported for seven compounds of a series of some 3-(4-chlorobenzyl)-5-benzylidene-imidazolidine-2, 4-diones and 3-(4-fluoro or chlorobenzyl)-5-benzylidene-thiazolidine-2, 4-diones previously synthesized.     

苦皮藤中两个新的 β-二氢沉香呋喃型化合物的 NMR 数据解析

从南蛇藤属植物苦皮藤中分离出两个新的β-二氢沉香呋喃型化合物：1β,2β,15-三乙酰氧基-8α-(α-甲基)-丁酰氧基-9β-苯甲酰氧基-4α,6α-二羟基-β-二氢沉香呋喃（化合物I）和1β,15-二乙酰氧基-8α-(α-甲基)-丙酰氧基-2β,9β-二苯甲酰氧基-4α,6α-二羟基-β-二氢沉香呋喃（化合物II）．通过核磁共振（NMR，包括¹H NMR、¹³C NMR、DEPT、¹H-¹H COSY、NOESY、HSQC、HMBC）技术对化合物所有的¹H和¹³C NMR信号进行了全归属和详细解析.     

海绵Ircinia Mutans Wilsion的化学成分

从中国南海海绵Ircinia mutans wilsion中首次分离得到的5个化合物,其结构确定为（32S,33R,34R）-Bacteriohopanetetrol（1）,3-吲哚甲醛（2）,3-羟基十一酸（3）,胸腺嘧啶（4）,对羟基苯甲酸乙酯（5）。     

Infrared Spectra of Protonated Pyrimidine Derivatives in the Solid State

Abstract

The infrared spectra of the complexes formed between 1-methyl, 2-pyrimidone, 3-methyl,4-pyrimidone, amino-2-pyrimidine, 1,3-dimethyl-uracil and HBr, HCl or DCl have been measured between 4000 and 300 cm^?1 in KBr. Complex formation brings about strong perturbations in the infrared spectra of the base. These vibrational perturbations are discussed in terms of structural data given by x-ray diffraction methods. Some vibrational modes of the bases are more sensitive to the deuteration and this fact is interpreted by different coupling between some planar vibration modes and the νNH⁺ or νND⁺ modes.     

Catalytic-oxidative/adsorptive denitrogenation of model hydrocarbon fuels under ultrasonic field using magnetic reduced graphene oxide-based phosphomolybdic acid (PMo-Fe3O4/rGO)

In this work, the effect of ultrasound irradiation on the catalytic oxidative/adsorptive denitrogenation (COADN) of model hydrocarbon fuels (composed of pyrrole or indole as an organonitrogen compounds dissolved in n-nonane) has been investigated using magnetic reduced graphene oxide supported with phosphomolybdic acid (PMo-Fe₃O₄/rGO) as a heterogeneous catalyst/adsorbent and hydrogen peroxide as an oxidant. The synthesized PMo-Fe₃O₄/rGO nanocomposite was characterized by XRD, FE-SEM, VSM and BET surface area analysis methods. Moreover, different experimental variables including catalyst dose, initial pyrrole/indole concentration, H₂O₂ to pyrrole/indole molar ratio, ultrasound power and sonication time have been studied on the COADN process. The regeneration/recyclability of PMo-Fe₃O₄/rGO catalyst was also examined. Experimental results revealed that, the ultrasound treatment significantly improved the adsorption process of organonitrogen compounds from model fuels (q_e increased by 50.3% for pyrrole and 18% for indole). Furthermore, high ultrasound-aided catalytic oxidative denitrogenation efficiency (85.6% for pyrrole and 90% for indole) has been attained under optimal conditions (ultrasonic power = 200 W, sonication time = 240 min, catalyst dose = 2 g/L, and H₂O₂:pyrrole/indole molar ratio = 5). The recyclability of catalyst displayed that the prepared catalyst can be reused five times without any significant reduction in its performance.     

Fluorescence Studies on Potential Antitumoral Heteroaryl and Heteroannulated Indoles in Solution and in Lipid Membranes

Fluorescence properties of three potential antitumoral compounds, a 3-(dibenzothien-4-yl)indole 1, a phenylbenzothienoindole 2 and a 3-(dibenzofur-4-yl)indole 3, were studied in solution and in lipid aggregates of dipalmitoyl phosphatidylcholine (DPPC), dioleoyl phosphatidylethanolamine (DOPE) and egg yolk phosphatidylcholine (Egg-PC). The 3-(dibenzofur-4-yl)indole 3 exhibits the higher fluorescence quantum yields in all solvents studied (0.32 ≤ Φ_F ≤ 0.51). All the compounds present a solvent sensitive emission, with significant red shifts in alcohols. The results point to an ICT character of the excited state, more pronounced for compound 1. Fluorescence (steady-state) anisotropy measurements of the compounds incorporated in lipid aggregates of DPPC, DOPE and Egg-PC indicate that the three compounds are deeply located in the lipid bilayer, feeling the difference between the rigid gel phase and fluid phases.     

Synthesis of 5-aryl-1,3-dimethyl-6-(alkyl- or aryl-amino) furo [2,3-d]pyrimidine derivatives by reaction between isocyanides and pyridinecarbaldehydes in the presence of 1,3-dimethylbarbituric acid

5-Aryl-6-(alkyl- or aryl-amino)-1,3-dimethylfuro [2,3-d]pyrimidine derivatives were obtained by in situ reaction alkyl or aryl isocyanides and pyridinecarbaldehyde derivatives in the presence of 1,3-dimethylbarbituric acid in dichloromethane without any prior activation or modifications.     

Optical properties,structure and electronic energy levels of the organicN-methyl, 2,3 diphenyl, 5-methyl indole compound

Summary The absorption properties of the new synthetized organicN-methyl, 2,3 diphenyl, 5-methyl indole compound have been studied. An X-ray diffraction analysis has been carried out in order to obtain the structural properties and the density of the material. Optical absorption spectra have been interpreted on the basis of a CNDO calculation of the energy levels. The results show a good agreement between theory and experiment. Work partially supported by Ministero della Pubblica Istruzione through CNR-CISM.     

An efficient synthesis of pyrido[2,3-d]pyrimidine derivatives and related compounds under ultrasound irradiation without catalyst

A series of pyrido[2,3-d]pyrimidine derivatives and related compounds were synthesized via the condensation reaction of an aldehyde, 2,6-diaminopyrimidine-4(3H)-one and either tetronic acid or 1,3-indanedione under ultrasonic irradiation without catalyst. This protocol has the advantages of higher yields, lower cost and convenient procedure.     

Combining click-multicomponent reaction: one-pot synthesis of triazolyl methoxy-phenyl indazolo[2,1-b]phthalazine-trione derivatives

[(1,2,3-Triazol-4-yl)methoxy-phenyl]-2H-indazolo[2,1-b]phthalazine-trione derivatives were synthesized in a simple and efficient method from the one-pot four-component condensation reaction of phthalhydrazide, aromatic propargyloxy aldehydes, active methylene compounds (dimedone and 1,3-cyclohexanedione), and azides in the presence of Cu(OAc)(2)/sodium ascorbate and p-toluenesulfonic acid as catalysts in good to excellent yields.     

Theory and experiment: Anion binding property of novel phenanthroline or aromatic bridged compounds

A series of artificial compounds, phenanthroline or aromatic bridged indoline derivatives, have been designed and synthesized. The interaction of these compounds with biologically important anions fluoride (F^?), acetate (AcO^?), dihydrogen phosphate (H₂PO₄^?), chloride (Cl^?), bromide (Br^?) and iodide (I^?) was determined by UV–vis, fluorescene titration and theoretical experiments. Results indicate that compound 1 (Di((1″,2″-dihydro-indol-3″-one-2″-hydrazone-1′-hydrazyl)-2′-methylene)-1,3-did-ehydebenzo) and 2 (Di((1″,2″-dihydro-indol-3″-one-2″-hydrazone-1′-hydrazyl)-2′-methylene)-1,3-didehyde-5-nitrobenzo) containing aromatic bridge do not show binding ability for various anions, and that compound 3 (Di((1″,2″-dihydro-indol-3″-one-2″-hydrazone-1′-hydrazyl)-2′-methylene)-2,9-dial-dehyde-1,10-phenanthroline) containing phenanthroline bridge shows the strongest binding ability for F^? among various anions, the moderate binding ability for AcO^? and H₂PO₄^?, and almost no binding ability for Cl^?, Br^?, I^?. The different binding ability of aromatic and phenanthroline bridged compounds may be related to the conjugative effect. What's more, the binding ability of compound 3 with F^? is not interfered by the existence of other anions. Hence, theoretical investigations explore the reasons of different binding ability between compound 3 and anions.     

DFT and ab initio study on non-linear optical (NLO) properties of some organic complexes with different conjugate linker and substituent groups

A series of Schiff-bases chromophores containing imine or double C=C bond linkers between the donor and acceptor have been studied by first-principles calculations. The molecular structures, electronic properties and second order nonlinearities were investigated by DFT and ab initio methods. The optimized structural parameters of these Schiff-base derivates showed that these compounds are stable. The results of TD-DFT calculations indicate that the derivatives with the heterocyclic and imine linker have a red shift absorption compared to derivatives with the double C=C or N=N bonds. The analysis of the frontier molecular orbitals indicates that the CN group and the heterocycle linked by the CN or imine group has contribution to the LUMO orbital while the groups N(CH₃)₂ and the benzene ring linked by the double C=C or N=N bond have contribution to the HOMO orbital. The CN and the heterocyclic acceptors enable the derivatives to have a larger first static hyperpolarizability. However, the compounds 3-{4-[(4-Dimethylamino-phenylimino)-methyl]-pyridin-1-yl}-propanel-1-sulfonoperoxoic acid and 3-{4-[(4-Dimethylamino-phenylimino)-methyl]-quinolin-1-yl}propanel-1-sulfonoperoxoic acid with a substituent also have large first static hyperpolarizabilities due to the overwhelming contributions of electron density of the group to the HOMO orbital, that is, the HOMO orbital were constituted by the SO ₃ ^? group only. In order to understand the influence of the energy gap (??E) between the HOMO and the LUMO orbitals on the first static hyperpolarizability, we calculated the energy gap (??E) of all Schiff-base compounds. The results show that the smaller the HOMO-LUMO energy gap the larger the first static hyperpolarizability. The present study demonstrated that these compounds which have pure C=N double bond and heterocyclic substitution groups may have potential applications in the development of NLO materials.     

One-pot synthesis of 1,2,3-triazole linked dihydropyrimidinones via Huisgen 1,3-dipolar/Biginelli cycloaddition

The combination of the Biginelli reaction with click chemistry has been used for the one-pot synthesis of 1,2,3-triazole linked dihydropyrimidinones from azides, aromatic aldehydes containing a propargyl ether group, urea, and 1,3-dicarbonyl compounds using Cu(OAc)₂/sodium ascorbate as catalyst in acetic acid under mild reaction conditions.     

东北苍耳子挥发油化学成分分析

利用乙醚抽提东北苍耳子挥发油,GC-MS结合计算机检索对其化学成分进行分析鉴定,用色谱峰面积归一化法计算各组分的相对含量.分离出89个组分,鉴定了其中74个组分,占总挥发油量的85.63%.东北苍耳子挥发油的主要成分为3-甲基丁酸(16.421%)、3-甲基-戊酸(15.882%)、苯乙醛(11.281%)、已酸(5.051%)、糠醛(4.716%)、苯甲醇(2.358%)、苯乙醇(2.282%)等.