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.

Reaction of N-cyanoguanidine with acid chlorides and aroylisothiocyanates gave the respective; N-(N-cyanocarbamimidoyl)aryl-2-carboxamides 1-5 and N-[(N-cyanocarbamimidoyl)carbamothioyl]benzamides 6-10, which have a Neonictinoid insecticide’s active group moiety (=N–CN). They have more toxicological activity against wheat Aphid (Schizaphis graminum) than Spodoptera littoralis.

Due to the complicated problems coming from excessive applications of insecticides, searching for safe substitutes to these insecticides has become a necessity. Thus, the insect growth regulators are candidates to be used in such concern. Comparative studies of the effects of three compounds, 2-benzoyl-N-phenylhydrazine-1-carbothioamide (1), 2-(cyanoacetyl)-N-phenylhydrazine-1-carboxamide (2) and N-(2-(2-cyanoacetyl)hydrazinecarbonothioyl)furan-2-carboxamide (3) (an insect growth regulator inhibiting chitin synthesis), were conducted on Spodoptera littoralis (Boisduval, 1833). The compounds, orally administered, caused larval mortality proportional to the concentrations in the food source. larvae were unable to complete the molting process and died in the old larval cuticle. Larvae contaminated by sublethal doses completed their development to adulthood. N-(2-(2-cyanoacetyl)hydrazinecarbonothioyl)furan-2-carboxamide (3) is more active than the other compounds have LC50 17.082 ppm for 2nd instar larvae and 60.832 ppm for 4th instar larvae.

In this review we systematized the theoretical and experimental data concerning the versatile approaches for the synthesis of N-acylphenothiazines. The aim of the study was to compile the literature reported worldwide in the past 20 years. This article also reviewed the analysis of pharmacological activities of these heterocycles as one of the promising chemotherapeutic objects for the modern bioorganic and medicinal chemistry. It has been hypothesized that the enormous biological potential of these moieties is due to the radical nature in the acyl moiety. Therefore, the present review will be a good contribution to the literature and will provide the platform for the medicinal chemistry researchers to carry out more studies aiming the N-acylphenothiazine moieties as the novel chemotherapeutic agents.

Biologically active organic compounds continue to attract great interest due to the wide variety of interesting applications observed for these compounds. This review results from the literature survey containing the organic compounds that are used as insect growth regulators with a focus on their mode of action and some synthetic routes.

Regioselective acylation of monosaccharides are highly significant for the preparation of both natural and non-natural carbohydrate compounds and their synthetic intermediates. In this respect, an efficient simple method for site selective 6-O-hexanoylation of octyl β-D-glucopyranoside (OG) at low temperature is described. The 6-O-hexanoylglucoside, thus formed, was then treated with five acyl halides and obtained novel corresponding O-acylglupyranosides at C-2, C-3 and C-4 positions with high yields. Activity spectra prediction for substances (PASS) indicated that these glucoside esters are potential against antimicrobials especially against fungi. In vitro antibacterial test indicated them as weak to moderate inhibitor of Gram-positive organisms. ADMET prediction indicated that these OGs are overall safe to use. Density functional theory (DFT) optimized electronic energy, enthalpy (ΔH), Gibbs free energy, entropy, dipole-moment (μ), and molecular electrostatic potential (MEP) are also discussed.

Amidoalkylation of secondary heterocyclic amines by N-[5-(alkylsulfanyl)-1,3,4-thiadiazol-2-yl]-2'-chloroacetamide resulted the new compounds 5-10 that contain 1,3,4-thiadiazole-5-thione moiety alongside pyperidine, morpholine, and cytisine fragments. In vitro screening of antimicrobial activity of synthesized compounds showed that N-[5-(amylsulfanyl)-1,3,4-thiadiazol-2-yl]-2'-morpholinacetamide exhibited an appreciable antibacterial activity against gram-negative bacteria of Escherichia coli (inhibition zone diameter of 16 mm) and gram-positive bacteria of Staphylococcus aureus and Bacillus subtilis (10-13 mm).

The aim of the research was to analyse fragrance allergens in selected alcohol-based perfumery products with the application of gas chromatography. Toilet waters and scented waters were analysed. Samples of the selected perfumery products were tested for the presence of typical allergens, such as linalool, citral, citronellol, geraniol, eugenol and alpha-isomethyl ionone, in the so-called fragrance concentrate. The obtained results showed that each of the products contained at least a few of the above-mentioned allergens. Nevertheless, the majority of the analysed products satisfied the recommendations of the Scientific Committee on Cosmetic Products and Non-food Products valid for cosmetics intended to remain on the skin for some time.

In this report, novel chromium incorporated fluorapatite encapsulated iron oxide (γ-Fe2O3@FAp@Cr) nanocatalyst was synthesized and characterized by FT-IR, TEM, SEM, XRD and EDX techniques. The catalyst was used in the synthesis of various derivatives of pyrazole-triazole hybrids via the reaction of thiosemicarbazide or semicarbaside and pyrazolecarbaldehydes at room temperature with excellent yields and short reaction times. The protocol was also used in the synthesis of bis-triazoles in high yield and reasonable reaction time. The nanocatalyst was comfortably separated from the reaction mixture by an external magnet and was reused in six consecutive cycles without any remarkable changes in its catalytic performance.

2-pyridyl [3H]-quinazolin-4-one derivatives fused or substituted with different oxygen or nitrogen heterocycle moieties as potential anti-tumor and anti-microbial agents were prepared, characterized and biologically screened. The synthesis process started from 5-bromo-2-[pyridin-4-ylcarbonyl]amino]benzoic acid which was converted to the crucial building block 6-Bromo-2-(pyridin-4-yl)quinazolin-4(3H)-one via two alternative routes. Compound 3 underwent halogenation reaction POCl3 and PCl5 to afford compound 6-Bromo-4-chloro-2-(pyridin-4-yl)quinazoline 4. The novel cyclized products 5a,b-10 were subsequently prepared. Some of the newly synthesized compounds 5a, 5b, 6, 7, 8, 9 and 10 were screened for their antiproliferative and antimicrobial activities against various eukaryotic and prokaryotic cells. Compound 9 showed selective antibacterial activity against Gram-positive bacteria S. aureus (IZ = 26 mm, MIC = 256 µg/ml) and may serve as a good candidate for further developmental studies.