Antibacterial activity of 2-amino-3-cyanopyridine derivatives

Crystal structure and Hirshfeld surface analyses, inter-molecular inter-action energies and energy frameworks of methyl 6-amino-5-cyano-2-(2-meth-oxy-2-oxoeth-yl)-4-(4-nitro-phen-yl)-4H-pyran-3-carboxyl-ate

The title compound, C17H15N3O7, contains pyran and phenyl rings, with the pyran ring exhibiting a flattened-boat conformation. In the crystal, inter-molecular N-H⋯N hydrogen bonds link the mol-ecules into centrosymmetric dimers, forming R 2 2(12) ring motifs. These dimers are linked through N-H⋯O hydrogen bonds into a three-dimensional architecture. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯O/O⋯H (29.7%), H⋯H (28.7%), H⋯C/C⋯H (16.0%) and H⋯N/N⋯H (12.9%) inter-actions. In addition to van der Waals inter-actions and N-H⋯N and N-H⋯O hydrogen bonds, halogen bonds, tetrel bonds and pnictogen bonds also play an important role in the cohesion of the crystal structure.

Synthesis, crystal structure and Hirshfeld surface analysis of 5-oxo-N-phenyl-3-(thio-phen-2-yl)-2,3,4,5-tetra-hydro-[1,1'-biphen-yl]-4-carboxamide

The asymmetric unit of the title com-pound, C23H19NO2S, contains two mol-ecules that differ in the conformation of the two carb-ox-amide moieties. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains propagating parallel to the c-axis direction. Between the mol-ecules, weak C-H⋯π(ring) inter-actions are present, whereas π-π inter-actions are not observed. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (47.6%), H⋯C/C⋯H (33.4%) and H⋯O/O⋯H (11.6%) inter-actions. Orientational disorder is observed for both thio-phene rings.

Green synthesis, anti-inflammatory evaluation and molecular docking of novel pyridines via one pot multi-component reaction using ultrasonic irradiation

In this paper, we present a green application for the synthesis of novel pyridine derivatives 4a-f via one-pot, multicomponent reaction (MCRs) of some aromatic aldehydes 1a-f with malononitrile (2) and N-(4-acetylphenyl)-4-methylbenzenesulfonamide (3) in the presence of ammonium acetate using ultrasonic irradiation (U.S) in an aqueous solvent H2O:EtOH (2:1). The structures of all synthesized pyridines 4a-f were confirmed via elemental analysis and different spectroscopic techniques. This application has many advantages such as avoiding hazardous solvents, excellent yields, inexpensive, simple application, in addition to obtain pure compounds. The anti-inflammatory activity of the newly compounds was examined with the reference drug Ibuprofen. The obtained results showed that most derivatives are promising anti-inflammatory activates. Moreover, compound 4b exhibits the most anti-inflammatory activity with a percentage of inhibition with 51.67% compared with Ibuprofen 53.96%. Furthermore, the newly compounds were studied in their molecular docking simulations against the enzyme Human Cyclooxygenase-2, with Tolfenamic Acid as a reference ligand (PDB ID: 5IKT). Compound 4b demonstrated a robust binding affinity with the target protein 5ikt, evidenced by its binding affinity score of - 11.16 kcal/mol, which is the highest among the studied compounds.

The Structure-Antiproliferative Activity Relationship of Pyridine Derivatives

Pyridine, a compound with a heterocyclic structure, is a key player in medicinal chemistry and drug design. It is widely used as a framework for the design of biologically active molecules and is the second most common heterocycle in FDA-approved drugs. Pyridine is known for its diverse biological activity, including antituberculosis, antitumor, anticoagulant, antiviral, antimalarial, antileishmania, anti-inflammatory, anti-Alzheimer's, antitrypanosomal, antimalarial, vasodilatory, antioxidant, antimicrobial, and antiproliferative effects. This review, spanning from 2022 to 2012, involved the meticulous identification of pyridine derivatives with antiproliferative activity, as indicated by their minimum inhibitory concentration values (IC50) against various cancerous cell lines. The aim was to determine the most favorable structural characteristics for their antiproliferative activity. Using computer programs, we constructed and calculated the molecular descriptors and analyzed the electrostatic potential maps of the selected pyridine derivatives. The study found that the presence and positions of the -OMe, -OH, -C=O, and NH2 groups in the pyridine derivatives enhanced their antiproliferative activity over the cancerous cellular lines studied. Conversely, pyridine derivatives with halogen atoms or bulky groups in their structures exhibited lower antiproliferative activity.

One-Pot, Four-Component Reaction for the Design, Synthesis, and SAR Studies of Novel Pyridines for Insecticidal Bioefficacy Screening against Cowpea Aphid (Aphis craccivora)

In this paper, novel pyridines 2-8 were designed and synthesized via the one-pot, four-component reaction of 2-formylphenyl 4-tolylsulfonate with malononitrile, ammonium acetate, and phenols or 2-thioxo-1,3-thiazolidin-4-one or 6-aminopyrimidine-2,4(1H,3H)-dione under microwave irradiation in an aqueous solution of water and ethanol (1:1 ratio). The structures of new pyridines 2-8 were elucidated by elemental and spectral analyses such as IR, 1H NMR, and 13CNMR. This application has many advantages, such as having easy workup, eco-friendliness, reaction time being short (6-13 min), high production (94-98%), inexpensiveness, and avoiding the use of harmful solvents. Moreover, all compounds have been investigated as insecticidal agents against cowpea aphid (Aphis craccivora) insects, and the toxicity effect was studied, followed by the structure-activity relationship. From the LC50 values, it has been found that compounds 7 and 8 were excellent and promising insecticidal agents, with LC50 values of 0.05 and 0.09 ppm against nymphs and 0.93 and 1.01 ppm against adults of cowpea aphid. Furthermore, the obtained results indicated that compounds 2-8 can be applied as insecticidal agents for the control of cowpea aphids and to protect agricultural crops from this destructive pest, which effects crop production and causes major economic damage.

Synthesis and Insecticidal Evaluation of 3,5-Dicyanopyridines Against Cotton Aphids via Microwave-Assisted Multicomponent Reactions

Certain 2-amino-6-alkoxy-4-arylpyridine-3,5-dicyanide 1a-e were prepared via a straightforward process using microwave technology rather than conventional methods. This involved reaction of arylidenemalononitrile thru propanedinitrile in the occurrence of sodium alkoxide under MW. While, their positional isomer 4-amino-6-alkoxy-2-arylpyridine-3,5-dicyanide 3a-j have been separated from the reaction of aryl aldehydes with 2-aminoprop-1-ene-1,1,3-tricarbonitrile 2 in the presence of sodium alkoxide using microwave technic. Furthermore, the insecticidal properties of all synthesized compounds were observed with respect to Cotton aphid nymphs and adults. Neonicotinoid pesticides are indicated as the most effective pesticides toward aphids and many other pests. Many insecticides are discovered as novelties. As a result, several pyridine compounds were chemical method synthesized to serve as equivalents of neonicotinoids, a broad class of insecticides. With LC50 value of 0.03 mg/L, components 3g exhibit the highest insecticidal bioactivity. This work discusses how to find new chemicals that could be used as insecticidal agents in the future.

Quinazolin-4-one/3-cyanopyridin-2-one Hybrids as Dual Inhibitors of EGFR and BRAFV600E: Design, Synthesis, and Antiproliferative Activity

A novel series of hybrid compounds comprising quinazolin-4-one and 3-cyanopyridin-2-one structures has been developed, with dual inhibitory actions on both EGFR and BRAFV600E. These hybrid compounds were tested in vitro against four different cancer cell lines. Compounds 8, 9, 18, and 19 inhibited cell proliferation significantly in the four cancer cells, with GI50 values ranging from 1.20 to 1.80 µM when compared to Doxorubicin (GI50 = 1.10 µM). Within this group of hybrids, compounds 18 and 19 exhibited substantial inhibition of EGFR and BRAFV600E. Molecular docking investigations provided confirmation that compounds 18 and 19 possess the capability to inhibit EGFR and BRAFV600E. Moreover, computational ADMET prediction indicated that most of the newly synthesized hybrids have low toxicity and minimal side effects.

Design, Synthesis, and Biological Evaluation of Novel 3-Cyanopyridone/Pyrazoline Hybrids as Potential Apoptotic Antiproliferative Agents Targeting EGFR/BRAFV600E Inhibitory Pathways

A series of novel 3-cyanopyridone/pyrazoline hybrids (21-30) exhibiting dual inhibition against EGFR and BRAFV600E has been developed. The synthesized target compounds were tested in vitro against four cancer cell lines. Compounds 28 and 30 demonstrated remarkable antiproliferative activity, boasting GI50 values of 27 nM and 25 nM, respectively. These hybrids exhibited dual inhibitory effects on both EGFR and BRAFV600E pathways. Compounds 28 and 30, akin to Erlotinib, displayed promising anticancer potential. Compound 30 emerged as the most potent inhibitor against cancer cell proliferation and BRAFV600E. Notably, both compounds 28 and 30 induced apoptosis by elevating levels of caspase-3 and -8 and Bax, while downregulating the antiapoptotic Bcl2 protein. Molecular docking studies confirmed the potential of compounds 28 and 30 to act as dual EGFR/BRAFV600E inhibitors. Furthermore, in silico ADMET prediction indicated that most synthesized 3-cyanopyridone/pyrazoline hybrids exhibit low toxicity and minimal adverse effects.

Discovery of new cyanopyridine/chalcone hybrids as dual inhibitors of EGFR/BRAF V600E with promising antiproliferative properties

As dual EGFR and BRAF^V600E inhibitors, 2-(3-cyano-4,6-bis(aryl)-2-oxo-1,2-dihydropyridine-1-yl)-N-(4-cinnamoylphenyl) acetamide derivatives 8-20 were developed. Compounds 8, 12, and 13 showed strong antiproliferative activity when the target compounds were synthesized and tested in vitro against four cancer cell lines. These hybrids have a dual inhibition activity on EGFR and BRAF^V600E , according to in vitro studies. The EGFR was inhibited by compounds 8, 12, and 13 with IC₅₀ values between 89 and 110 nM, which were equivalent to those of erlotinib (IC₅₀  = 80 nm). Compound 13 was found to be an effective inhibitor of the proliferation of cancer cells (GI₅₀  = 0.72 µM) and demonstrated hopeful inhibitory activity of BRAF^V600E (IC₅₀  = 58 nm), which is superior to erlotinib (IC₅₀  = 65 nm). Compound 13 caused apoptosis and showed cell cycle arrest in the G0/G1phase in a study on the MCF-7 cell line. The new compounds can fit tightly into the active sites of EGFR and BRAF^V600E kinases, according to molecular docking analyses.

Crystal structures and Hirshfeld surface analyses of 2-amino-4-(4-bromo-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile hemi-hydrate and 1,6-di-amino-2-oxo-4-phenyl-1,2-di-hydro-pyridine-3,5-dicarbo-nitrile

In 2-amino-4-(4-bromo-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile hemihydrate, C18H14BrN3O·0.5H2O, (I), pairs of mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming dimers with an R 2 2(12) ring motif. The dimers are connected by N-H⋯Br and O-H⋯O hydrogen bonds, and C-Br⋯π inter-actions, forming layers parallel to the (010) plane. 1,6-Di-amino-2-oxo-4-phenyl-1,2-di-hydro-pyridine-3,5-dicarbo-nitrile, C13H9N5O, (II), crystallizes in the triclinic space group P with two independent mol-ecules (IIA and IIB) in the asymmetric unit. In the crystal of (II), mol-ecules IIA and IIB are linked by inter-molecular N-H⋯N and N-H⋯O hydrogen bonds into layers parallel to (001). These layers are connected along the c-axis direction by weak C-H⋯N contacts. C-H⋯π and C-N⋯π inter-actions connect adjacent mol-ecules, forming chains along the a-axis direction. In (I) and (II), the stability of the packing is ensured by van der Waals inter-actions between the layers. In (I), Hirshfeld surface analysis showed that the most important contributions to the crystal packing are from H⋯H (37.9%), C⋯H/H⋯C (18.4%), Br⋯H/H⋯Br (13.3%), N⋯H/H⋯N (11.5%) and O⋯H/H⋯O (10.0%) inter-actions, while in (II), H⋯H inter-actions are the most significant contributors to the crystal packing (27.6% for mol-ecule IIA and 23.1% for mol-ecule IIB).

Nanostructured Na2CaP2O7: A New and Efficient Catalyst for One-Pot Synthesis of 2-Amino-3-Cyanopyridine Derivatives and Evaluation of Their Antibacterial Activity

A facile and novel synthesis of thirteen 2-amino-3-cyanopyridine derivatives 5(a–m) by a one-pot multicomponent reactions (MCRs) is described for the first time, starting from aromatic aldehydes, malononitrile, methyl ketones, or cyclohexanone and ammonium acetate in the presence of the nanostructured diphosphate Na2CaP2O7 (DIPH) at 80 °C under solvent-free conditions. These compounds were brought into existence in a short period with good to outstanding yields (84–94%). The diphosphate Na2CaP2O7 was synthesized and characterized by different techniques (FT-IR, XRD, SEM, and TEM) and used as an efficient, environmentally friendly, easy-to-handle, harmless, secure, and reusable catalyst. Our study was strengthened by combining five new pyrido[2,3-d]pyrimidine derivatives 6(b, c, g, h, j) by intermolecular cyclization of 2-amino-3-cyanopyridines 5(b, c, g, h, j) with formamide. The synthesized products were characterized by FT-IR, 1H NMR, and 13C NMR and by comparing measured melting points with known values reported in the literature. Gas chromatography/mass spectrometry was used to characterize the newly synthesized products and evaluate their purity. The operating conditions were optimized using a model reaction in which the catalyst amount, temperature, time, and solvent effect were evaluated. Antibacterial activity was tested against approved Gram-positive and Gram-negative strains for previously mentioned compounds.

Crystal structure and Hirshfeld surface analysis of 5-acetyl-2-amino-4-(4-bromo-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile

The crystal structure of the title compound, C20H16BrN3O2, was determined using an inversion twin. Its asymmetric unit comprises two crystallographically independent mol-ecules (A and B) being the stereoisomers. Both mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming a dimer with an R 2 2(16) ring motif. The dimers are connected by further N-H⋯O and N-H⋯N hydrogen bonds, forming chains along the c-axis direction·C-Br⋯π inter-actions between these chains contribute to the stabilization of the mol-ecular packing. Hirshfeld surface analysis showed that the most important contributions to the crystal packing are from H⋯H, C⋯H/H⋯C, O⋯H/H⋯O, Br⋯H/H⋯Br and N⋯H/H⋯N inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-amino-4-(4-meth-oxy-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile

The central tetra-hydro-pyridine ring of the title compound, C19H17N3O2, adopts a screw-boat conformation. In the crystal, strong C-H⋯O and N-H⋯N hydrogen bonds form dimers with R 2 2(14) and R 2 2(12) ring motifs, respectively, between consecutive mol-ecules along the c-axis direction. Inter-molecular N-H⋯O and C-H⋯O hydrogen bonds connect these dimers, forming a three-dimensional network. C-H⋯π inter-actions and π-π stacking inter-actions contribute to the stabilization of the mol-ecular packing. A Hirshfeld surface analysis indicates that the contributions from the most prevalent inter-actions are H⋯H (47.1%), C⋯H/H⋯C (20.9%), O⋯H/H⋯O (15.3%) and N⋯H/H⋯N (11.4%).

Crystal structure and Hirshfeld surface analysis of (Z)-2-amino-4-(2,6-di-chloro-phen-yl)-5-(1-hy-droxy-ethyl-idene)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile

The mol-ecular conformation of the title compound, C20H15Cl2N3O2, is stabilized by an intra-molecular O-H⋯O hydrogen bond, forming an S(6) ring motif. The central pyridine ring is almost planar [maximum deviation = 0.074 (3) Å]. It subtends dihedral angles of 86.10 (15) and 87.17 (14)°, respectively, with the phenyl and di-chloro-phenyl rings, which are at an angle of 21.28 (15)° to each other. The =C(-OH)CH3 group is coplanar. In the crystal, mol-ecules are linked by inter-molecular N-H⋯N and C-H⋯N hydrogen bonds, and N-H⋯π and C-H⋯π inter-actions, forming a three-dimensional network. The most important contributions to the crystal packing are from H⋯H (33.1%), C⋯H/H⋯C (22.5%), Cl⋯H/H⋯Cl (14.1%), O⋯H/H⋯O (11.9%) and N⋯H/H⋯N (9.7%) inter-actions.