Organic Chemistry Research
Volume:5 Issue: 1, Summer 2019

A simple, efficient, and cost-effective procedure for the N-tert-butoxycarbonylation and N-formylation of amines (primary, secondary) respectively, with di-tert-butyl dicarbonate and 85% aqueous formic acid under solvent-free condition using B(OSO3H)3/SiO2 (SBSA) as a heterogeneous and recyclable catalyst has been developed. We demonstrated that the resulting catalyst is applicable to various aromatic and aliphatic amines giving excellent yields of the desired products in short reaction time (

A new immobilized palladium-pyridine complex on γ-Fe2O3 magnetic nanoparticles was synthesized and characterized by SEM, TEM, TGA, ICP, XPS, XRD, FT-IR and CHN analysis. The catalytic activity of synthesized catalyst has been investigated in Heck, Suzuki and Sonogashira coupling reactions using a series of aryl halides. The catalyst was easily isolated from the reaction mixture by an external magnetic field and reused several times with no significant loss of catalytic activity.

A series of interesting sulfonamides containing hydroxyl group were synthesized under solvent-free conditions. The synthetic route involves the selective reaction of amino alcohol and sulfonating agents. The sulfonamides were obtained by simple procedure after an easy work-up in high yield and purity, and characterized by IR, 1H NMR and 13C NMR analysis. These compounds were tested for antibacterial activity against four bacterium including Escherichia Coli, Staphylococcus Aurous, Bacillus Subtilis and Salemonella Typhi.

A combined experimental and theoretical investigation has been reported on N-(2-pyridyl)-para-styrene sulfonamide (abbreviated as PSS). This compound synthesized from the reaction of para-styrene sulfonyl chloride and 2- amino pyridine. The PSS was confirmed using FT-IR, 1H-NMR spectroscopy. MEP and HOMO-LUMO analysis of the PSS have been investigated using DFT method. The PSS is investigated against Staphylococcus aureus and Escherichia coli. Molecular Docking study is also reported.

2-Azetidinones, commonly known as β-lactams, are well-known heterocyclic compounds. Herein we described the synthesis of a series of novel β-lactams. The efficient and rapid synthesis of novel β-lactams has been established in good yields starting from (R)-3-phenyl-2, 3, 6, 7-tetrahydroimidazo [2', 1':2, 3] thiazolo [5, 4-d] isoxazole 1. First, (R)-3-phenyl-2, 3, 6, 7-tetrahydroimidazo [2', 1':2, 3] thiazolo [5, 4-d] isoxazole 1 on condensation with ethylchloro acetate yielded Ethyl (R) 2-(3-phenyl- 6, 7-dihydroimidazo [2', 1':2,3] thiazolo [5, 4-d] isoxazole-2(3H)-yl) acetate 2, which on amination with hydrazine hydrate yielded (R) 2-(3-phenyl- 6, 7-dihydroimidazo [2', 1':2, 3] thiazolo [5, 4-d] isoxazol -2(3H)-yl) acetohydrazide 3. Then, condensation between compound 3 and various aromatic aldehydes give Schiff base derivatives 4a-j, which upon dehydrative annulation in the presence of chloroacetyl chloride and triethylamine yielded N-((3S, 4S)-3-chloro-2-oxo-4-phenylazetidin-1-yl)-2-((R)-3-(Aryl)-6, 7-dihydroimidazo [2', 1':2, 3] thiazolo [5, 4-d] isoxazol -2(3H)-yl) acetamide 5a-j. All synthesized compounds were characterized by elemental analyses, IR, 1H-NMR and 13C-NMR data.the formula is not displayed correctly!

In this research, to overcome the low mechanical properties of hydrogels based on Poly N-isopropylacrylamide (PNIPAAm) and improve their stimuli responsive behavior and lower critical solution temperature LCST, a new kind of hybrid magnetic nanoparticles was designed and prepared and then grafted to (PNIPAAm-co-AAc) hydrogel through in situ dispersion copolymerization route. 3-(propylcarbamoyl)acrylic acid functionalized silica-coated magnetic nanoparticles (PC-AAc/MNPs) was prepared and used as a template for in situ dispersion copolymerization of the poly N-isopropylacrylamide (PNIPAAm) and acrylic acid (AAc) in the presence of methylene-bis-acrylamide as a cross-linking agent via free radical cross-linking polymerization. Also, controlled drug release behavior of metronidazole was investigated with prepared nanocomposite hydrogels. The vibrating sample magnetometer (VSM) illustrated superparamagnetic behavior for (PC-AAc/MNPs) and nanoparticles grafted hydrogel. Scanning electron microscopy (SEM) image of functionalized magnetic nanoparticles showed that they are spherical in shape and have the spherical structure with a diameter of about 15-30 nm. Moreover, the lower critical solution temperature (LCST) of the (PC-AAc/MNPs-g-PNIPAAm-co-AAc) hydrogel, as well as the onset temperatures, measured by the cloud point (CP) method at ~ 42 C. Combined magnetic properties and thermosensitive behavior of (PNIPAAm-co-AAc) grafted magnetic nanoparticles could be utilized in controlled drug-targeting delivery. Hence, metronidazole as a model drug loaded on the magnetic hydrogel nanocomposite and the amount of drug release was measured by UV-Vis spectroscopy.

Quinazolinones were synthesized through the one-pot three-component reaction of aromatic aldehydes, isatoic anhydride, and urea under solvent-free conditions using sulfonic acid functionalized mesoporous silica (SBA-Pr-SO3H). The propargyl ether containing 2,3-dihydroquinazolin-4(1H)-ones were reacted with sodium azide in the presence of CuI to gain the new triazole-quinazolinone products.

2,3,5,6-tetrachloro-4-iodopyridine was successfully synthesized in one-step from the reaction of pentachloropyridine with sodium iodide using microwave irradiation. The reaction of O, N, and S centered nucleophiles with 2,3,5,6-tetrachloro-4-iodopyridine was studied in order to assess regiochemistry of aromatic nucleophilic substitution. Substitution occurs at the para position to ring nitrogen by S centered nucleophiles, while O and N centered nucleophiles substitution occurs at the ortho position of pyridine ring. IR, 1H NMR, and 13C NMR spectroscopy, confirmed the structures of all the compounds.

In this research, we have synthesized polystyrene sulfonic acid as a new heterogeneous solid acid. Then, we have synthesized 2,3-dihydroquinazolin-4(1H)-ones via condensation of 2-aminobenzamide and different aldehydes in the presence of polystyrene sulfonic acid. The major advantages of the present method are good yields, ecofriendly and easy work-up.

Cyclization of unsymmetrical thioureas affords N-(6-substitued-1,3-benzothiazol-2-yl)-4-phenyl-1,3-thiazol-2(3H)-imine compounds by the reaction of 1-(1,3-benzothiazol-2-yl)thiourea derivatives and 2-bromoacetophenone in the presence of Et3N. Also, methyl-1,3-benzothiazol-2-yl carbamodithioate derivatives with methyl anthranilate were reacted and 3-(benzo[d]thiazol-2-yl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one derivatives as new compounds are synthesized. In the following, synthesized compounds (2a- 2d) were evaluated for anti-tumor activity against MCF-7, MAD-MD-231, HT-29, HeLa, Neuro-2a, K-562 and L-929 cell lines and the results obtained from MTT-assay revealed the best cytotoxicity for 2b compound containing a phenolic segment in their buildings. On the other hand, apoptosis assay for this compound was also carried out by flow cytometry supporting the other results.

In this report a green strategy for the synthesis of polyhydroacridine derivatives via one-pot three-component coupling reaction of arylaldehydes, 1,3-cyclohexanedione and aniline derivatives in the presence of modified montmorillonite (Fe3+@mont.) as heterogeneous and reusable catalyst under solvent-free conditions was developed. The reaction in the presence of this catalyst furnished the desired products in short reaction times (10-15 min.) and high to excellent yields (78-98%).

Triethylaminium-N-sulfonic acid tetrachloroaluminate (TSAT) as a new ionic liquid was synthesized and characterized by its FT-IR, 1H, 13C NMR and mass spectra as well as TG and DTG diagrams. This ionic liquid was employed as a catalyst for the synthesis of [1,2,4]triazolo[1,5-a]pyrimidines-6-carboxamides via one-pot three-component reaction of aromatic aldehydes, acetoacetanilide and 3-amino-1,2,4-triazole under solvent-free conditions at 60 °C .The salient features of the present protocol are mild reaction condition, easy isolation of products and clean reaction profiles.