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Intramolecular oxa-6π-electrocyclization reaction are described for 3-allylideneindolin-2-one derivatives in the presence of easily prepared B(HSO4)3 catalyst and their conversion to 2,9-dihydropyrano[2,3-b]-indoles in up to 72% yield under mild condition. 3-allylideneindolin-2-one has been obtained from the reaction of isatin and 1,3-dichloropropene. Comfortable synthetic conversions of the products readily lead to pharmacologically interesting numerous functional groups. [ABSTRACT FROM AUTHOR]

A one-pot synthesis of 3-alkoxycarbonyl-3,4-dihydro-2H-pyran-2-ones from intermolecular hetero-Diels–Alder reaction between vinylidene Melderum's acids and dialkyl acetylenedicarboxylates, in the presence of simple alcohols at room temperature, is described. The advantages of this procedure are good yields, short reaction time, and easy workup. Antioxidant properties of four derivatives of these 3,4-dihydro-2H-pyran-2-ones, together with their antimicrobial activities, are investigated. [ABSTRACT FROM AUTHOR]

In this study, water extract of Spinacia oleracea leaves was used for the synthesis of Fe3O4/TiO2/MWCNTs magnetic nanocomposites and high performance of this catalyst was confirmed by employing it in the solvent-free multicomponent reactions of anilines, oxalyl chloride, diamines or hydroxyamines, electron-deficient acetylenic ester, α-haloketones and Et3N at room temperature for the generation of new spiropyrroloindoles in high yields. This catalyst could be utilized several times and has a significant role in the yield of product. The synthesized spiropyrroloindoles have NH and OH group in their structure and for this reason have good antioxidant activity. Also, by employing Gram-positive and Gram-negative bacteria and the disk diffusion procedure confirmed the antimicrobial effect of some spiropyrroloindole derivatives. The results showed that synthesized spiropyrroloindoles prevented the bacterial growth. This used process for preparation of new spiropyrroloindoles has some improvements such as low reaction time, product with high yields, and simple separation of catalyst and products. [ABSTRACT FROM AUTHOR]

In the present work (E) -2-(4-oxo-4,5-dihydrothiazol-2-yl)-2-(2-oxoindolin-3-ylidene) acetonitrile compounds were obtained from the reaction of isatin and 2-(4-oxo-4,5-dihydrothiazol-2-yl) acetonitrile in a green solvent with good yield. In this paper, we have developed an attractive alternative to the classical Knovnagel condensation for the Diastereoselective synthesis of this compound which can be used as starting material for the synthesis of novel tetrazole compound by an oxindole moiety. The percentage of the (Z) isomer was very low (4%) and was determined by NMR. The result was investigated computationally, calculations were performed and optimizations were carried out the density functional theory (DFT) with the Basis set M062X \ 6-31G *. [ABSTRACT FROM AUTHOR]

In this work, a novel and simple catalytic system including FeCl2, PPh3 and potassium tert-butoxide has been employed for the synthesis of imines from amines. In order to prove the catalytic acceptorless dehydrogenation pathway for this transformation, the liberated H2 gas is detected by NMR spectroscopy. By utilizing this protocol, a variety of arylamines were used successfully for the preparation of corresponding imines in good to excellent yields (on a 1 mmol scale, 73–91% yield for homocoupling, 71 and 91% for heterocoupling). [ABSTRACT FROM AUTHOR]

In this paper, pH-sensitive magnetic hydrogels were prepared from carboxymethyl cellulose (CMC), β-cyclodextrin (β-CD) and chitosan (CS) without a toxic agent by a simple method as a new carrier for a controlled drug release. Magnetic (Fe3O4) nanoparticles were synthesized by chemical co-precipitation via in situ method under the presence of N2 gas. The effect of magnetic (Fe3O4) nanoparticles amounts on CMC, β-CD and CS hydrogel for drug delivery of Methotrexate (MTX) was investigated. The stability of hydrogel was evaluated using TGA, XRD, VSM, FT-IR, and FE-SEM measurements. The SEM images demonstrated the Fe3O4 distribution in the hydrogel, while XRD patterns confirmed the cubic crystalline phase of Fe3O4 nanoparticles. The hysteresis loop of low magnetic CMC/β-CD/CS hydrogel and high magnetic CMC/β-CD/CS hydrogel is 6.32 and 11.6 emug−1, respectively. The swelling manner of the CMC/β-CD/CS hydrogels was studied at a varied pH range 2–11. CMC/β-CD/CS hydrogel demonstrated slightly higher swelling amount as compared to magnetic CMC/β-CD/CS hydrogel. The prepared hydrogel showed a pH-sensitive swelling manner with great water-absorbing at pH 9. The maximum capacity of swelling in CMC/β-CD/CS hydrogel, low and high magnetic CMC/β-CD/CS hydrogels were obtained 8.8, 6.7 and 4.6 g g−1 respectively. In vitro, MTX release experiment was performed to attain the success of this new method of magnetic CMC/β-CD/CS hydrogel for drug delivery progress. The results showed that the release percent of CMC/β-CD/CS hydrogel was more significant than the other prepared hydrogel. The maximum drug release in CMC/β-CD/CS hydrogel, low and high magnetic CMC/β-CD/CS hydrogels were obtained 92.7, 80.4 and 58.3% at pH 7.4, respectively. Also, the MTX release investigated under an external alternating magnetic field (AMF). The studies illustrated that the response of hydrogel nanocomposite to external stimulants could be used for novel drug delivery systems. [ABSTRACT FROM AUTHOR]

Using density functional theory calculations (based on the B3LYP/6-31G(d) method), we investigated the functionalization of a BN nanosheet (B33N33H22) by different α-amidino carboxylic acids (ACA). It was found that the pristine BN sheet can be noncovalently functionalized by the ACA with an adsorption energy of about − 2.7 kcal/mol. Also, the results showed that structural Stone–Wales (SW) defects significantly increase the adsorption energy. The SW-BN nanosheet transforms from an insulator to a semiconductor by covalent functionalization. Incorporating –NH2 and –NO2 groups in the structure of the ACA molecule increases and decreases the adsorption energy, respectively. The –NH2 group compared to the –NO2 was found to be more favorable for covalent functionalization especially when it is substituted at the meta position of phenyl group of ACA molecule. Investigating the effect of some other electron donating groups showed that the favorability order of applied groups for functionalization is as follows: –N(CH3)2 > –OH > –NH2 > –OCH3 > –Phenyl > –F. Furthermore, it was found that the solubility of BN nanosheets significantly increases, depending on the type of functional group. [ABSTRACT FROM AUTHOR]

Trifluoroethanol as an efficient media for the domino Knoevenagel-hetero-Diels-Alder reaction of O-propargyloxy benzaldehydes as non-activated terminal alkynes with some active methylene compounds has been described. Short reaction time, easy work-up, good to high yields, and mild reaction conditions are advantages of this new media. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A set of novel Schiff bases of isatin were synthesized and characterized by reaction of isatin with various aromatic or heterocyclic primary amines. Cytotoxic activities for some of the synthesized compounds were evaluated by MTT assay in three human cancer cell lines (HeLa, LS180 and Raji). Half of the tested compounds showed good cytotoxicity in HeLa cells. 3-(2-(4-nitrophenyl) hydrazono) indolin-2-one was found to be the most potent molecule among the studied isatin derivatives. Docking studies of 3-substituted indolin-2-one scaffolds on vascular endothelial growth factor receptor 2 (VEGFR-2) involved in cell proliferation and angiogenesis was performed. 3-(naphthalen-1-ylimino) indolin-2-one and 3-(2-(4-nitrophenyl) hydrazono) indolin-2-one exhibited higher docking binding energies with receptor. For 3-(2-(4-nitrophenyl) hydrazono) indolin-2-one, H-bond interaction with Cys917 residue of target active site was in common with reported crystallographic benzoimidazole derivative (PDB code: 2OH4). New key H-bonds involving Glu915, Asn921, and Arg1049 residues in VEGFR-2 active site could be detected for 3-(2-(4-nitrophenyl) hydrazono) indolin-2-one. Extended lipophilic rings containing H-bond acceptors on the 3 position of indoline scaffold seemed to be important factors in developing potent VEGFR-2 inhibitors virtually. Based on the ligand efficiency indices, some isoxazole or thiazole substituted isatin derivatives may be regarded as efficient candidates for further molecular developments of anticancer agents. [ABSTRACT FROM AUTHOR]

1-Aryl- N, N-dimethyl-1 H-naphtho[1,2- e][1,3]oxazine-3-amine derivatives were synthesized in moderate to high yields using a novel, facile, and one-pot condensation of N, N, N′, N′-tetramethylguanidine, aromatic aldehydes, and β-naphthol under microwave-assisted conditions. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A new one-pot four component procedure for synthesis of densely functionalized pyrroles using commercially available ninhydrin with phosphorane intermediates produced in the reaction between triphenylphosphine, ammonium thiocyanate (or ammonium acetate) and various dialkyl acetylenedicarboxylates was developed. [ABSTRACT FROM AUTHOR]