The new organocatalyst amine-iodine-iodide complex (DBUHI3) was prepared and used as a catalyst for the synthesis of 2,4,5-trisubstituted imidazoles in moderate to good yields from inexpensive, commercially available and eco-friendly ammonium acetate as a nitrogen source, 1,2-diketones and substituted aromatic aldehydes. The direct one-step multicomponent efficient synthesis was achieved with remarkable green advantages offered by this protocol such as short reaction time, the broad scope of a substrate, and simple experimental procedure.

A series of 6-(Aryl)-4-[4-(2,4-dichlorophenylmethoxy)-3-methoxyphenyl]-2,3,4,5-tetrahydro-indazol-3-one derivatives (3a-3i) have been synthesized by refluxing of previously synthesized Ethyl-4-(aryl)-6-[4-(2,4-Dichlorophenylmethoxy)-3-methoxyphenyl]-2-oxo-cyclohex-3-eneoates (2a-2i) with hydrazine hydrate in methanol for 7-8 hours in presence of catalytic amount of glacial acetic acid. The analytical and physical data of all the synthesized compounds (2a-2i) and (3a-3i) were observed and reported. The structures of each newly synthesized Indazole derivative have been characterized by various methods like Elemental analysis, Infrared spectroscopy, 1H-NMR and 13CMR spectroscopy and Mass spectroscopy. Furthermore, each compound was screened for its in-vitro antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal towards fungi Aspergillus niger (A. niger) and Candida albicans (C. albicans) with the concentration of 40 μg/ml and data was collected.

A sequence of thioxotetrahydropyrimidenes derivatives, N-(4-chloro/methoxyphenyl)-3-formyl-6-methyl-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxamides (4a-l) were synthesized by the formylation of N-(4-chloro/methoxyphenyl)-6-methyl-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxamides (3a-l) by dry dimethyl formamide (DMF) and phosphorous oxychloride at room temperature. Formerly, compounds (3a-l) were synthesized by the condensation of N-(4-chloro/methoxyphenyl)-3-oxobutanamide (1), various aromatic aldehydes (2a-f) and thiourea with catalytic amount of concentrated hydrochloric acid under reflux temperature. The structures of the synthesized various thioxotetrahydropyrimidenes have been characterized by using elemental analysis, Infrared, ¹H-NMR, ¹³C-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity towards Aspergillus niger at a concentration of 40 µg/ml. It was showing that the compounds 4a, 4e, 4g, 4h, 4i and 4l displayed inspirational antibacterial and antifungal activity compared to the used reference standard.

Nanomaterials have attracted a great deal of attention from the scientific community due to their unique properties and applications. The small size metal oxides have opened up the door for intensive research to utilize their properties for biomedical applications. Silver nanoparticle (AgNPs) and metal oxide nanomaterials like MgO, ZnO, NiO and its silver doped nanocomposites (Ag-MgO, Ag-ZnO, Ag-NiO) have been prepared using solid state combustion method using polyvinyl alcohol (PVA) as a fuel. The structure of as prepared oxides and its silver doped nanocomposites were characterized using X-ray diffraction (XRD) tool and morphology by Scanning Electron Micrograph (SEM) tool as well as Transmission electron micrograph tool respectively. Presence of the metals in the oxides and its Ag composite was confirmed by the EDX pattern. Bonding nature in the composite is well studied by the Fourier transform infrared (FT-IR) tool. Antibacterial activity studies of the nanocomposites are carried out against various bacteria.

Fused pyrimidines play an imperative role in our life due to their biological importance in the struggle of microorganisms. A series of 4-aryl-3-methyl-1-phenyl-1,4,6,7-tetrahydropyrazolo[3,4-d] thiazolo[3,2-a]pyrimidine (4a-j) were synthesized by cyclization of 3-methyl-1-phenyl-4-aryl-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-d]pyrimidine-6-thiones (3a-j) with 1,2-dibromoethane in presence of anhydrous potassium carbonate. Earlier, compounds (3a-j) were synthesized by the condensation of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one (2), different substituted benzaldehyde and thiourea with catalytic amount of con. HCl in methanol. Compound 2 was synthesized by condensation of ethyl acetoacetate (1) and phenylhydrezine in presence of a catalytic amount of acetic acid at reflux temperature. The constitution of the synthesized products has been characterized by using elemental analysis, Infrared, ¹H-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial and antifungal activity at concentration of 500 μg/ml. It was exposed that most of the compounds displayed inspiring antibacterial and antifungal activity compared to the used reference standard.

A series of isoxazole derivatives, 3-aryl-5-[5-(4-nitrophenyl)-2-furyl]-2,3-dihydroisoxazoles (5a-j) were synthesized by cyclocondensation reaction between 1-aryl-3-[5-(4-nitrophenyl)-2-furyl]prop-2-en-1-ones (4a-j) and hydroxylamine hydrochloride in presence of sodium acetate in glacial acetic acid at reflux temperature. Formerly, compounds (4a-j) were synthesized by the condensation of 5-(4-nitrophenyl) furan-2-carbaldehyde (3) with various aromatic ketones by using alkali as catalyst. The structures of the synthesized various isoxazole have been characterized by using elemental analysis, Infrared,¹H-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity towards Aspergillus niger at a concentration of 40 µg/ml. It was exposed that the compounds 5a, 5c, 5e, 5f, and 5i showed inspiring antibacterial and antifungal activity compared to the used reference standard.

A series of N-acetyl pyrazole derivatives, 1-acetyl-3-aryl-5-[5'-(4-nitrophenyl)-2'-furyl]-4,5-dihydro-1H-pyrazoles (5a-j) were synthesized by cyclocondensation reaction between 1-aryl-3-[5-(4-nitrophenyl)-2-furyl]prop-2-en-1-ones (4a-j) and hydrazine hydrate in glacial acetic acid at reflux temperature. Before that, compounds (4a-j) were synthesized by the condensation of 5-(4-nitrophenyl) furan-2-carbaldehyde (3) with various aromatic ketones by using alkali as catalyst. The constitution of the synthesized products has been characterized by using elemental analysis, Infrared,¹H-NMR, ¹³C-NMR spectroscopy and further supported by Mass spectroscopy. All the products have been screened for their in-vitro biological assay like antibacterial activity towards Gram-positive and Gram-negative bacterial strains and antifungal activity towards Aspergillus niger at a concentration of 40 µg/ml. It was exposed that the compounds 5a, 5b, 5c, 5d, 5g, 5h and 5j showed motivating antibacterial and antifungal activity compared to the used reference standard.

Oxygen-containing heterocycles are largely distributed in natural and synthetic compounds. Coumarins are among the most famous heterocycles which possess one oxygen atom in their rings. Coumarins are classified as multifunctional scaffold and are used as anti-oxidant reagents, anti-inflammatory, anti-microbial, anti-fungal, anti-HIV active, analgesic, anti-histaminic, insecticides, dyes, herbicides, sensitizers, perfumes, cosmetics and food additives. Due to their diverse applications in industrial and pharmaceutical fields, many chemists have given significant interest to these compounds. Herein, the review highlights various methods for the synthesis and interactions of coumarin moiety as one of the most efficient categories of heterocycles.

A series of some new pyrazole-substituted 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines was synthesized in this study. The structures of target substances were confirmed by using 1H and 13С NMR spectroscopy, mass spectrometry and elemental analysis. The synthesized compounds have been evaluated for antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). The antimicrobial screening studies of synthesized substances established that 2 of 12 compounds show pronounced antibacterial activity against the strain Staphylococcus aureus.

Different methods for the synthesis of pyridine derivatives as well as the chemical reactivity profiles and structures of these substances are reviewed. The utility of these compounds as precursors is emphasized in the synthesis of many heterocycles that are pharmacologically active organic compounds and agrochemicals. This review results from a literature survey containing some synthetic methods and applications of pyridine derivatives.