A Convenient One-Pot Synthesis of Some New 3-(2-Phenyl-6-(2-thienyl)-4-pyridyl)hydroquinolin-2-ones Under Microwave Irradiation and Their Antimicrobial Activities

A series of 3-(2-phenyl-6-(2-thienyl)-4-pyridyl)hydroquinolin-2-ones 4a–o were synthesized in high yields by a one–pot cyclocondensation reaction under Kröhnke's reaction conditions using 2-chloro-3-formyl quinoline 1a–c, 2-acetyl thiophene 2, and various N-phenacylpyridinium bromides 3a–e in a mixture of ammonium acetate and acetic acid by microwave irradiation. All the compounds have been characterized by elemental analysis, FT-IR, ¹H NMR, and ¹³C NMR spectral analysis. These compounds have been screened for their antimicrobial activities.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and Herbicidal Activities of 2-Methylpropan-2-Aminium Methyl 1-(Substituted Phenoxyacetoxy) Alkylphosphonates

Abstract

A series of 2-methylpropan-2-aminium methyl 1-(substituted phenoxyacetoxy) alkylphosphonates were selectively synthesized by reacting the corresponding dimethyl 1-(substitutedphenoxyacetoxy)alkylphosphonates with an excess of 2-methylpropan-2-amine. All the title compounds were identified by IR, ¹H NMR, and ³¹P NMR, some of them were further analyzed by ¹⁹F NMR and ¹³C NMR. Their herbicidal activity was investigated and the results showed that most of the demethylated aminium salts exhibited notable herbicidal activities against Brassica napus L. and Echinochloa crusgalli.

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

Green chemistry approach to the synthesis of 3-substituted-quinazolin-4(3H)-ones and 2-methyl-3-substituted-quinazolin-4(3H)-ones and biological evaluation

ABSTRACT

A synthesis of two series of 3-substituted quinazolinones was performed utilizing a green chemistry approach, deep eutectic solvents and microwaves, namely. 2-Methyl-3-substituted-quinazolin-4(3H)-one derivatives were synthesized in a two-step reaction, using choline chloride:urea deep eutectic solvent (DES). 3-Substituted-quinazolin-4(3H)-ones were synthesized in one-pot one-step reaction of anthranilic acid, amines and orthoester in a microwave reactor. For the synthesis of 2-methyl-3-substituted-quinazolin-4(3H)-ones, first conventional synthesis of benzoxazinone, as an intermediate, was performed. Further, benzoxazinone in reaction with corresponding amines, in choline choline:urea deep eutectic solvent, furnished desired compounds. These procedures are based on green principles with the aim of developing synthetic routes for the potential antitumor agents. All compounds were characterized by LC/MS, ¹H NMR and ¹³C NMR spectral techniques. Compound 1 bearing trifluoromethoxyphenyl group showed promising activity against HuT-78 cell line with IC₅₀ of 51.4?±?5.1?µM.     

1H, 13C and 199Hg NMR Studies of the Complexation of HgCl2 by Imidazolidine-2-Thione and its Derivatives

Abstract

Mercury(II) complexes of imidazolidine-2-thione and its derivatives have been synthesized and their ¹H, ¹³C and ¹⁹⁹Hg NMR spectra measured. HgCl₂ forms L₂HgCl₂ type complexes (where L = imidazolidine-2-thione and its derivatives). The NH group of the ligand is shifted downfield by about +1.37 ppm in the ¹H NMR after complexation. The C-2 carbon in the ¹³C NMR is shifted by—6.50 ppm for mono N-substituted ligands, but by—5.30 ppm for N,N''-disubstituted ligands. The ¹⁹⁹Hg NMR resonance is shifted by about—60 ppm for N-substituted ligands, but—140 ppm shifts were observed for N',N'-disubstituted ligands.     

Microwave synthesis,anti-oxidant and anti-tumor activity of some nucleosides derived 2-oxonicotinonitrile

Abstract

A facile and convenient synthesis of novel cyclic and acyclic nucleoside derivatives incorporating 2-oxo-1,2-dihydropyridine-3-carbonitrile moiety has been described. The aglycons 3a,b were coupled with different activated halosugars such as glucosyl, galactosyl, lactosyl bromides and peracetylated ribose, in addition to, acyclic sugar as 4-bromobutylacetate and 2-acetoxyethoxymethyl bromide in basic medium under conventional and microwave irradiation. Deprotection of the synthesized nucleosides was obtained in presence of Et₃N/MeOH and few drops of water. The structures of the synthesized compounds have been deduced from their elemental analyses and spectral data (IR, ¹H NMR, and ¹³C NMR). Some of the synthesized compounds were screened as antioxidant and anticancer agents. Good and moderate anticancer activities against HepG-2, PC-3 and HCT116 were observed in vitro for some compounds.     

Synthesis,Spectroscopic Studies,and Biological Activity of Organosilicon(iv) Complexes of Ligands Derived from 2-Aminobenzothiazole Derivatives and 2-Hydroxy-3-Methoxy Benzaldehyde

Abstract

The Schiff bases derived from the condensation of 2-aminobenzothiazole derivatives and 2-hydroxy-3-methoxybenzaldehyde and their silicon(IV) complexes with the general formula R₂Si(L)Cl (R = Et, Bu, Ph, L = 2-(2-hydroxy-3-methoxy) benzylideneaminobenzo-thiazole) have been synthesized. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including IR and NMR (¹H, ¹³C, and ²⁹Si) spectroscopy. The analytical data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Staphylococcus aureus, Bacillus subtilis, and Escherichia coli) and fungi (Aspergillus niger and Candida albicans). The complexes were found to be more potent as compared to the ligands.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Microwave-Assisted Efficient Methylation of Alkyl and Arenesulfonamides with Trimethylsulfoxonium Iodide and KOH

Abstract

A solvent-free synthesis of N-methyl and N,N-dimethylsulfonamides has been achieved by treating the primary and secondary sulfonamides with Me₃S⁺OI^? and KOH under microwave irradiation on alumina support.     

Crystal Structure and Spectroscopic Properties of (2-oxo-2H-chromen-3-yl)phosphonic Acid Monoethyl Ester Trihydrate

Abstract

(2-Oxo-2H-chromen-3-yl)phosphonic acid monoethyl ester trihydrate (1) was synthesized, isolated, and spectroscopically as well as structurally characterized by means of single crystal X-ray diffraction; conventional and linear-polarized IR spectroscopy; electronic (UV-VIS-NIR) spectroscopy; ¹H, ¹³C, and ³¹P NMR. Quantum chemical DFT calculations have been performed in order to obtain information on the electronic structure and vibrational properties of 1, thus supporting the experimental data. The correlation between the structure and spectroscopic characteristics is discussed.

GRAPHICAL ABSTRACT      

CeCl3·7H2O Catalyzed,Microwave-Assisted High-Yield Synthesis of α-Aminophosphonates and their Biological Studies

Abstract

A new class of diethyl(3,5-dibromo-4-hydroxyphenylamino) (substituted phenyl/heterocyclic) methylphosphonates 4(a–j) has been synthesized by one-pot three component simultaneous reaction (Kabachnik–Fields) of 4-amino-2,6-dibromophenol 1, substituted heterocyclic/phenyl aldehydes 2(a–j), and diethylphosphite 3 using a Lewis acid catalyst, CeCl₃·7H₂O (5 mol%) under microwave irradiation as well as conventional conditions. It was observed that microwave irradiation method is more facile, efficient, and advantageous with respect to reaction time and yields. The structures of all the synthesized compounds were supported by analyzing IR, ¹H/¹³C/³¹P NMR, and mass spectral data. The synthesized compounds were screened for their in vitro antimicrobial and antioxidant activities.     

微波辐射下5-取代-2-硫代海因衍生物的合成

微波辐射下, 由硫氰酸铵与α-氨基酸通过两步反应合成了11种5-取代-2-硫代海因衍生物, 并用¹H NMR, IR和元素分析确证了中间产物和终产物的结构. 对比常规加热方法, 微波辐射具有反应时间短(4 min), 每步反应产率高(85%～93%)的优点. 同时对合成化合物2h的反应历程进行了讨论.     

3-(5-Substituted 2-Methoxyphenyl)-4-Nitro-2-Phenyl-5-Thiophene-2-yl-Isoxazolidines - Synthesis and Conformational Studies

Abstract

The synthesis of a new set of 2,3,4,5-substituted isoxazolidines having a sulfur containing heterocyclic moiety has been described. The structural features of the compounds have been analyzed by ¹H and ¹³C NMR spectroscopy as well as by single crystal X-ray studies.

[Supplemental 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 resource: .cif file.]     

Synthesis,Spectroscopic Analysis,and In-Vitro Antimicrobial Evaluation of some Tetrahydrobenzo[a]Xanthene-11-Thiones

Abstract

A series of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-thiones were synthesized by the reaction of substituted 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-ones with Lawesson's Reagent in toluene under standard reaction conditions. All synthesized compounds were characterized by IR, NMR (¹H and ¹³C), and mass spectra. Moreover, 2D-NMR (HOMOCOSY, HSQC, and HMBC) studies were also performed for compound 10b. The synthesized compounds were also screened for their antibacterial activities.

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

One-Pot Green Synthesis of 3'-(2-Aminobenzimidazolyl)-2-Phenyl Spiro[4H-Benzopyran-4,2'-Thiazolidin]-4-Ones and Acylation Using Trifluoroacetic Anhydride

Abstract

An expeditious one-pot synthesis of a novel heterocyclic system, 3′-(2-aminobenzimidazolyl)-2-phenyl spiro[4H-benzopyran-4,2′-thiazolidin]-4-ones, has been accomplished by condensing substituted hydrazinobenzimidazole, flavanone, and mercaptoacetic acid by conventional heating in ethanol or toluene, and in an ionic liquid, viz., 1-butyl-3-methyl-imidazolium hexafluorophosphate. Excellent yields (85%–90%) and higher purity are obtained in the ionic-liquid-mediated synthesis as compared with the conventional procedure (55%–60%). Further, these compounds were acylated with trifluoroacetic anhydride. The structures of the compounds were confirmed by IR, ¹H NMR, ¹³C NMR, mass spectral data, and elemental analysis. The compounds, upon evaluation for their antibacterial, antifungal, and insecticidal activities, exhibited excellent results.

[Supplemental 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 resource: Table S1, S2, and S3]

GRAPHICAL ABSTRACT      

Synthesis and Characterization of New Thebaine Derivatives: 2-(6,14-endo-Ethenotetrahydrothebaine-7α;-yl)-5-(N-Arylamino)-1,3,4-Thiadiazoles

Abstract

We have synthesized a series of novel 2-(6,14-endo-ethenotetrahydrothebaine-7α-yl)-5-N-arylamino-1,3,4-thiadiazoles (5a–n) as potential narcotic analgesics, which are analogs of morphine. The synthesized compounds exhibit rigid morphine structures, including a 6,14-endo-entheno bridge and a 5-N-arylamino-1,3,4-thiadiazol-2-yl group at C-7 position that adopted S-configuration. The structures and stereochemistry of the compounds were completely assigned using one- and two-dimensional NMR experiments (¹H NMR, APT, COSY, NOESY, HMQC, and HMBC), FTIR, and high-resolution mass spectral (HRMS) data.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

金属氯化物对硼氢化钠还原α-氯代苯乙酮的影响

以芳醛、麦氏酸和3-甲基-1-苯基-5-氨基吡唑为原料, 经微波辐射一步得到4-芳基-3-甲基-6-氧代-1-苯基-4,5,6,7-四氢吡啶并[2,3-c]吡唑衍生物, 反应2～6 min完成, 产率高. 产物结构通过红外、核磁共振、元素分析及单晶X射线分析确证.     

Synthesis and Bioassay of Ethyl-2- (2-((Diethoxyphosphoryl) (Aryl) Methylamino)Thiazol-4-Yl)-2-(Methoxyimino)Acetates

Abstract

A simple, efficient, and environmentally benign methodology has been accomplished for the synthesis of α-aminophosphonates by one-pot three-component reaction of ethyl-2-amino-α-(methoxy-imino)-4-thiazoleacetate, aldehydes, and diethylphosphite by using Amberlyst-15 as catalyst at room temperature under solvent-free conditions. Their chemical structures were characterized by infrared (IR), NMR (¹H, ¹³C & ³¹P), mass spectral, and elemental analysis. All the title compounds were screened for radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitic oxide (NO), and hydrogen peroxide (H₂O₂) methods.

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 and figures.     

Synthesis and antitumor activity of new silver(I)-N-heterocyclic carbene complexes

Abstract

In this study, two novel benzimidazole-based N-heterocyclic carbene ligands (1a-b) and their silver(I) complexes (2a-b) were synthesized. All new compounds were characterized by FT-IR, LC-MS, ¹H NMR, and ¹³C NMR spectroscopies. The in vitro antitumor activities of NHC ligands (1a-b) and their silver(I) complexes (2a-b) against DU-145 human prostate cancer cells, MDA-MB-231 and MCF-7 human breast cancer cells and L-929 (normal cells adipose from mouse) were also determined using MTT analysis for 24?h, 48?h, and 72?h. The results showed that while NHC ligands did not have in vitro antitumor activity on MCF-7, MDA-MB-231 and DU-145 cells, Ag(I)-NHC complexes have in vitro antitumor activities. The in vitro antitumor activity of 2a was found to be lower than that of 2b. Ag(I)-NHC complexes were observed to have higher IC₅₀ values for non-cancerous cell lines than cancer cells.     

Synthesis,Characterization, and Structures of Tetrakis(2-Pyridyl)Tin Compounds

Abstract

Reactions of 2-bromopyridine and 2-bromo-6-methylpyridine with n-BuLi and tin tetrachloride afforded Sn(2-py)₄ (1a) and Sn(6-Me-2-py)₄ (1b), respectively. The identities of the two compounds were unambiguously proved by microanalyses, NMR (¹H, ¹³C, ¹¹⁹Sn) spetroscopy, and single-crystal X-ray diffraction studies.     

Eco-Friendly Synthesis and Insecticidal Activity of Some Fluorinated 2-(N-Arylamino)-4-Arylthiazoles

A series of fluorinated 2-(N-arylamino)-4-arylthiazoles (3) was synthesized by the condensation of appropriate arylthioureas (2) with corresponding α-bromoacetophenones (1) by using “green chemistry” techniques, viz. mechanochemical mixing and microwave or ultrasonic irradiation. Compared with conventional procedures, the reaction can be carried out under milder conditions, requiring a shorter reaction time and giving higher yields following the green chemistry methodology. All the synthesized compounds were characterized on the basis of elemental analyses and spectral data (IR, ¹H NMR, and mass spectrometry). Representative compounds were also evaluated for their insecticidal activity against Helicoverpa armigera, and some of them showed promising activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Facile synthesis and characterization of novel benzo-fused macrocyclic dicarbonitriles and pyrazolo-fused macrocycles containing thiazole subunits

Abstract

Novel bis[2-(thiazol-2-yl)acetonitriles], linked to aliphatic cores via ethers, were prepared by the reaction of the appropriate bis(2-bromoethan-1-one) with 2-cyanothioacetamide in dioxane at reflux. Bis[2-(thiazol-2-yl)acetonitriles] were taken as key intermediates for the preparation of a new class of macrocyclic dicarbonitriles bearing two thiazole units and containing two O₂-donor sets and fused with two benzene units. The target macrocyclic dicarbonitriles were prepared by the cyclocondensation of bis[2-(thiazol-2-yl)acetonitriles] with the appropriate bis(aldehydes) in N,N-dimethylformamide in the presence of piperidine at reflux. Moreover, a new class of pyrazolo-fused macrocycles containing thiazole subunits were prepared by the reaction of macrocyclic dicarbonitriles with hydrazine hydrate in ethanol at reflux. The structures of the novel macrocycles bearing thiazole subunits were elucidated by considering their elemental analyses as well as their IR, mass, ¹H NMR and ¹³C NMR spectral data.