Oxidative Rearrangement of Isatins with Arylamines Using H2O2 as Oxidant： A Facile Synthesis of Quinazoline-2,4-diones and Evaluation of Their Antibacterial Activity

A green and highly efficient synthetic method for the synthesis of quinazoline-2,4-diones with hydrogen peroxide as the terminal oxidant has been developed, The reaction features the mild reaction conditions, broad substrate scope, metal-free catalysts, and sole byproduct water. A plausible mechanism for this process was proposed. Moreover, an antibacterial activity study was performed to evaluate the antimicrobial activities towards two Gram-negative bacterial strains （Escherichia coli, and Klebsiella pneumonia） and two Gram-positive bacterial strains （Staphylococcus epidermidis, and Staphylococcus aureus） using the Broth microdilution method.

HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones from indoles and isatins

The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are described.This protocol shows well tolerance of different functional groups and features mild reaction conditions such as short reaction time(~1 h),no usage of catalyst,easy operation and product isolation.Of particular intere st is the formation of two C-C bonds and one all-carbon quaternary center.This protocol could serve as an alternative strategy to synthesize biologically important 3,3-di(indolyl)indolin-2-ones for biological testing.

Dimethyl sulfoxide-aided copper(0)-catalyzed intramolecular decarbonylative rearrangement of N-aryl isatins leading to acridones

Described here is the first example of Cu(0)-catalyzed intramolecular decarbonylative rearrangements of readily available N-aryl isatins assisted by solvent dimethyl sulfoxide(DMSO)under air atmosphere and additive-free conditions leading to various biologically important acridones in good to excellent yields.This novel transformation is proposed to go through a sequential DMSO-aided Cu insertion into the amide C-N bond,CO extrusion,Cu migration,reductive elimination and DMSO-aided proton migration processes,involving multiple types of bond cleavage and formation in a single chemical step.

Synthesis and antibacterial activity of Schiff bases of 5-substituted isatins

Based on the existing reports on the bioactive isatin derivatives, a number of Schiff bases were synthesized by reacting 5-substituted isatins with bioactive amines/hydrazides and their structures were confirmed using spectroscopic methods such as NMR, IR and mass spectrometry. Furthermore, Nbenzylation of isatin followed by the Schiff base formation furnished a new series of compounds（11a-13c） which allowed the analysis of the effect of isatin N-substitution on the bioactivity of the resulting compounds. The antibacterial activity of the synthesized derivatives was evaluated using a microtiter plate method on a series of gram positive and gram negative bacterial strains. Compounds 2d, 3b, 5c and 6a were among the most potent derivatives against Pseudomonas aeruginosa（MIC = 6.25 μg/m L）.Analysis of the structure-activity relationship showed that the incorporation of（thio）urea-based Schiff bases lead to more potent derivatives with a broader spectrum of antibacterial activity. In addition,highly lipophilic compounds such as 11a-12c did not show any measurable antibacterial activity, which implies that an optimal lipophilicity might be an important requirement for the antibacterial activity of the studied isatins. Finally, the finding that hydantoin derivatives of N-benzylisatins（13a-13c） still exhibit some antibacterial activity prompted us to consider exploring the bioactivity of more diverse derivatives of isatin-aminohydantoin Schiff bases（compounds 1a-1d） in our future studies.

A New Cyclization/Decarboxylation Reaction of Isatins with Acyl Chlorides for the Facile Synthesis of 3-Alkenyl-oxindoles

The first cyclization/decarboxylation reaction of isatins with acyl chlorides promoted by 4-dimethylaminopyridine(DMAP)was described and a series of desired 3-alkenyl-oxindoles were obtained in good yields(up to 80%)and E/Z selectivities(up to 6.4/1).This protocol provided a new and feasible access to 3-alkenyl-oxindoles.

Synthesis, spectral, 3D molecular modeling and antibacterial studies of dibutyltin (IV) Schiff base complexes derived from substituted isatin and amino acids

New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, and biological activity. The analytical data showed that the Schiff base ligand acts as bidentate towards metal ions via the azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of M:L (1:2) to form metal complexes. NMR (1H, 13C and 119Sn) spectral data of the ligands and metal complex agree with proposed structures. The conductivity values between 14 - 27 ohm-1cm2mol-1 in DMF imply the presence of non-electrolyte species. 3D molecular modeling and analysis of bond lengths and bond angles have also been conducted for a representative compound, [Bu2Sn(L2)2], to substantiate the proposed structures. Antibacterial results indicate that the metal complexes are more active than the free ligands.

Antipyretic Action of Isatin and Its Analogues in Mice and Rats

The effects of isatin (2,3-dioxo-indole) and isatin analogues (5-methylisatin, 6-hydroxyisatin, 7-ethylisatin, N-acety- lisatin) were tested on prostaglandin E2 (PGE2)-induced fever in mice and rats. Two modes of administration were tested. Isatin or an analogue was injected simultaneously with PGE2 and the development of fever was tested, or the test compound was given 30 min following PGE2 administration and the effects on the already existing fever were measured, in mice and in rats. Isatin in a dose of 3.12 mg/kg ip was found to block the development of PGE2-induced fever in mice, while in a dose of 12.5 mg/kg ip it attenuated the existing fever. In rats isatin in a dose of 12.5 mg/kg ip blocked fever initiation, and at 25.0 mg/kg ip attenuated existing PGE2-induced fever. In mice, 5-methylisatin in a dose of 0.21 mg/kg ip blocked the initiation of fever, and at 6.72 mg/kg ip attenuated the existing fever. In rats in a dose of 3.36 mg/kg ip it blocked the development of fever, and at 13.44 mg/kg ip attenuated existing PGE2-induced fever. In mice 5,6-dimetylisatin in a dose of 0.02 mg/kg ip both blocked fever initiation and attenuated the existing fever in mice, in rats in a dose of 0.42 mg/kg ip it blocked the initiation of fever, and at 0.21 mg/kg ip attenuated the existing PGE2-induced fever. In mice 6-hydroxyisatin in a dose of 5.2 mg/kg blocked the development of fever, and at 10.4 mg/kg attenuated the existing fever. In rats in a dose of 10.40 mg/kg ip it blocked fever development and also attenuated the existing fever. In mice, 7-ethylisatin in a dose of 0.02 mg/kg ip both blocked fever initiation and also attenuated the existing fever. In rats, a dose of 0.11 mg/kg both blocked fever initiation and also attenuated the existing fever. In mice, N-acethylisatin in the dose of 0.005 mg/kg blocked fever initiation, while at 1.024 mg/kg it attenuated existing fever, in rats, in a dose of 0.096 mg/kg it blocked fever initiation, and at 0.384 mg/kg attenuated the existing fever. The results demonstrate that 7-ethyl- and N-acetylisatin are the most effective of these compounds both in blocking the development of PGE2-induced fever and also in attenuating existing the PGE 2-induced fever.

Synthesis and in vitro Antimycobacterial Activity of Moxifloxacin Methylene and Ethylene Isatin Derivatives

A series of novel moxifloxacin methylene and ethylene isatin derivatives with remarkable improvement in lipophilicity, compared to the parent moxifloxacin, was designed, synthesized and characterized by 1H NMR, MS and HRMS. These derivatives were initially evaluated for their in vitro antimycobacterial activity against M. smegmatis CMCC 93202. Compounds 3a―3f, 5a, 5f and 5j were chosen for the further evaluation of their in vitro activity against Mycobacterium tuberculosis（MTB） H37Rv ATCC 27294 and MDR-MTB 09710. All the target com pounds[minimum inhibitory concentration（MIC）： 0.39―〉16 μg/mL] were far more active than rifampin（MIC： 2.0―〉256 μg/mL）, but less active than moxifloxacin（MIC： 0.1―1.0 μg/mL） against the three tested strains. The most active compounds 3a and 3c were found to be 2―64 fold more potent than isoniazid and rifampin against M. smegmatis CMCC 93202, 2 fold more potent than rifampin against MTB H37Rv ATCC 27294, and 16―〉64 fold more potent than ethambutol, isoniazid and rifampin against MDR-MTB 09710.

Isatin decreases Bax protein expression in the substantia nigra of a mouse model of Parkinson's disease

The present study observed the action of 1H-indole-2, 3-dione （isatin） on Bax protein expression in the substantia nigra of a Parkinson＇s disease animal model. Parkinson＇s disease-like behaviors were induced in C57BL/6J mice treated with 1-methyl-4-phenyl-1,2, 3, 6-tetrahydropyridine （MPTP） Bax protein expression was significantly reduced in isatin （100, 200 mg/kg）-pretreated mice. Results demonstrate that isatin plays a neuroprotective role in mice treated with MPTP by down-regulating Bax protein expression.

Acylhydrazide and Isatin Schiff Bases as Alternate UV-Laser Desorption Ionization (LDI) Matrices for Low Molecular Weight (LMW) Peptides Analysis

Matrix-assisted laser desorption/ionization (MALDI) is a preferred and widely used mass spectrometric technique for the analysis of macromolecules. Limited UV-LDI matrices are available for the analysis of biomolecules due to the restricted structural features to serve in the laser desorption/ionization mechanism with a problem of background signals appearing in the low mass region. This paper describes the application of Schiff base derivatives of acylhydrazide and isatin as alternate UV-LDI matrices for the analysis of peptides with significantly low background signals. Thirty one compounds have been successfully employed as matrices for the analysis of low molecular weight (LMW) peptides (α-Cyano-4-hydroxycinnamic acid (HCCA), a preferred choice for peptide analysis.

New Approach to Synthesis of 6,7-Dimethoxyisatin

A new approach to synthesis of 6,7-dimethoxyisatin is reported. 2-nitro-3, 4- dimethoxy mandelonitrile in glacial acetic acid was treated with the solution of stannous chloride in hydrochloric acid to give 6, 7-dimethoxyisatin in a high yield.

Synthesis and Crystal Structure of 1′-Methyl-4′- (4-chlorophenyl)-1H-indole-3-spiro-2′-pyrrolidine- 3′-spiro-4''-(2''-phenyloxazole)-2,5''(3H,4''H)-dione

The title compound （C26H20ClN3O3） has been synthesized by 1,3-dipolar cycloaddition reaction from isatin, sarcosine and （Z）-4-（4-chlorobenzylidene）-2-phenyloxazol-5（4H）-one through a one-pot procedure, and its structure was confirmed by IR, IH NMR, elemental analysis and single-crystal X-ray diffraction analysis. The crystal belongs to the triclinic system, space group PI, with a = 9.3903（19）, b = 11.398（2）, c = 12.603（3） A, α = 83.495（3）, β = 68.988（3）, γ = 67.178（3）^o, V= 1160.1（4）A^3 Z = 2, Mr= 457.90, Dc= 1.311 g/cm^3, p = 0.198 mm ^-1, F（000） = 476, the final R = 0.0489 and wR = 0.1144 for 3109 observed reflections with I 〉 2σ（I）.

Syntheses,Crystal Structures and Bioactivities of Two Isatin Derivatives

The title compounds（Z）-3-（2-（3-chloropyridin-2-yl）hydrazono）indolin-2-one（A） and 7-bromo-（Z）-3-（（4-pyridinyl）carboxlichydrazono）-2-indolinone（B） have been synthesized and structurally determined by elemental analysis and single-crystal X-ray diffraction studies.Compound A（C13H8ClN4O） belongs to the orthorhombic crystal system,space group Pca21 with a = 20.799（4）,b = 4.9312（10）,c = 11.764（2）,V = 1206.6（4）3,Mr = 271.68,Dc = 1.496 g/cm3,μ = 0.313 mm-1,F（000） = 556,Z = 4,the final R = 0.0346 and wR = 0.0831 for 2683 observed reflections with I 2σ（I）.Compound B（C14H9BrN4O2） belongs to the triclinic crystal system,space group P1 with a = 6.6834（13）,b = 7.0727（14）,c = 14.285（3）,α = 95.56（3）,β = 99.00（3）,γ = 102.95（3）°,V = 643.8（2）3,Mr = 345.16,Dc = 1.780 g/cm3,μ = 3.203 mm-1,F（000） = 344,Z = 2,the final R = 0.0487 and wR = 0.1167 for 2334 observed reflections with I 2σ（I）.The preliminary herbicidal bioassay reveals that compounds A and B have some inhibition both in vivo and in vitro against AHAS.

Syntheses,Crystal Structures and Bioactivities of Two Novel Isatin Derivatives

Two novel compounds 1-（4-fluorobenzyl）-4-chloro-（Z）-3-benzoylhydrazono-2-indolinone（1） and 1-（4-methoxybenzyl）-（Z）-3-benzoylhydrazono-2-indolinone（2） were synthesized and their crystal structures were determined by single-crystal X-ray diffraction.Compound 1（C22H15ClFN3O2） crystallized in the triclinic system,space group P1·with a=0.94198（19） nm,b=1.4339（3） nm,c=1.5018（3） nm,α=101.58（3）°,β=102.96（3）°,γ=102.73°,V=1.8602（6） nm3,Mr=407.82,Dc=1.456 g/cm3,μ=0.240 mm-1,F（000）=840,Z=4,R1=0.0442 and wR2=0.1064.Compound 2（C23H19N3O3） crystallized in the triclinic system,space group P1·with a=1.0022（2） nm,b=1.0192（2） nm,c=1.0461（2） nm,α=99.86（3）°,β=117.30（3）°,γ=94.13（3）°,V=0.9215（3） nm3,Mr=385.41,Dc=1.389 g/cm3,μ=0.094 mm-1,F（000）=404,Z=2,R1=0.0403 and wR2=0.1142.The preliminary herbicidal activities of the two compounds were also evaluated.

Synthesis and Antibacterial Studies of Metal Complexes of Cu(II), Ni(II) and Co(II) with Tetradentate Ligand

The new metal complexes of Cu(II), Ni(II) and Co(II) with the new ligand derived from isatine and 1,2-diaminocyclohexane were synthesized and biologically screened. The synthesized complexes and ligand were characterized by spectroscopic FT-IR, UV-VIS, 1H-NMR and elemental analyses. The ligand and complexes were screened for their antibacterial activities against three different strains, namely E. coli, P. aeruginosa and S. aureus. In particular, the Co(II) and Cu-complexes exhibited excellent antibacterial activities compared to the reference compound.

Catalyst and Solvent-Free Microwave Assisted Expeditious Synthesis of 3-Indolyl-3-hydroxy Oxindoles and Unsymmetrical 3,3-Di(indolyl)indolin-2-ones

A simple and efficient method for the synthesis of 3-indolyl-3-hydroxy oxindoles and unsymmetrical 3,3-di(indolyl)indolin-2-ones using microwave irradiation without catalyst and solvent is described. A series of 3-indolyl-3-hydroxy oxindoles and unsymmetrical 3,3-di(indolyl)indolin-2-ones have been synthesized in very short reaction times of 5 and 10 minutes and in yields ranging from 31% to 98% and from 53% to 78% respectively. This method offers a significant advantage over the conventional methods in terms of simplicity and shorter reaction time. To the best of our knowledge compounds N-allyl-3-hydroxy-3-(1-methyl-indol-3-yl)indolin-2-one (6c), N-allyl-3-hydroxy-3-(5-methoxy-indol-3-yl)indolin-2-one (8c), N-benzyl-3-hydroxy-3-(1-methyl-indol-3-yl) indolin-2-one (10c), N-propargyl-3-hydroxy-3-(1-methyl-indol-3-yl)indolin-2-one (13c), N-propargyl-3-hydroxy-3-(5-methoxy-indol-3-yl)indolin-2-one (14c), 3-(5-methoxy-1H-indol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (1e), 3-1-methyl(5-methoxy-1H-indol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (2e), 3-1-allyl(5-methoxy-1H-indol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (3e), 3-1-benzyl(5-methoxy-1H-in- dol-3-yl)-3-(1H-indol-3-yl)indolin-2-one (4e) and 3-1-(prop-2-ynyl)(5-methoxy-1H-indol-3-yl)-3(1H-indol-3-yl)indolin-2-one (5e) are reported here for the first time. All the compounds are characterized by IR, 1H, 13C NMR and HRMS.

Synthesis, Characteristic and Antimicrobial Activity of Some New Spiro[indol-thiazolidon-2,4-diones] and Bis(5-fluorospiro[indoline-3,2’-thiazolidine]-2,4’-dione) Probes

In a search for new antimicrobial agents, some new spiro[indol-thiazolidon- 2,4-diones] (6a-c) were synthesized by condensation of 5-substituted isatins 1 with sulfanilamide in MeOH, followed by aroylation with p-nitrobenzoyl chloride in DMF to get compounds 4a-c. Cycloaddition of 4a-c with thioglycolic acid in a dry non-polar solvent (dioxane) gave the targets 6a-c. Also, bis(5-fluorospiro[indoline-3,2’-thiazolidine]-2,4’-dione) (9) was synthesized by condensation of 5-fluoroindoline-2,3-dione with benzene-1,4-diamine (2:1 by mol) in MeOH, which followed by cycloaddition with thioglycolic acid in dioxane gave compound 8. Acylation of the later with 2,2,2-trifluoroacetic anhydride in THF has yielded the target 9. Structures of the products have been deduced from their elemental analysis and spectral data. The in vitro antimicrobial activity of the new systems 6a-c, and 9 was tested.

Indolin-2-Ones in Clinical Trials as Potential Kinase Inhibitors: A Review

The kinases have been intensely studied because of their involvement in regulating essential cellular activation of signaling cascades in response to extracellular and intracellular stimuli to control cell growth, proliferation, and survival. Recent cancer genomic sequencing studies have revealed that many more kinases contribute to tumor genesis and are potential targets for inhibitor drug development intervention. Herein we review recent results that have helped to unravel the indolin-2-ones underlying the confiicting roles of the kinase inhibition regulation. This review focuses on the potential of kinases as a chemotherapeutic target in cancer treatment and highlights important recent advances in the development of indolin-2-ones as kinase inhibitors.

Synthesis of 3＇,4＇-Diaryl-4＇H-spiro[indoline-3,5＇-[1＇,2＇,4＇]- oxadiazol]-2-ones via DMAP-catalyzed Domino Reactions and Their Antibacterial Activity

A convenient and metal-flee DMAP-catalyzed domino reaction of isatins, arylamines and hydroximoyl chlorides has been developed to achieve 1,3-dipolar cycloaddition of imines into aryl nitrile oxides at ambient tempera- ture. In this one-pot transformation, a 1,2,4-oxadiazole skeleton was efficiently formed. This methodology needs no extra additives and features wide substrate scope, good functional group tolerance and mild reaction conditions. A plausible mechanism for this process was proposed. Moreover, the antibacterial activities of the products were evaluated towards Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae using the Broth microdilution method.