Microwave-assisted synthesis of phenylpyrimidine derivatives via Suzuki-Miyaura reactions in water

The Synergy of Microwave-Irradiation and Water Surface: A Fast Access to C-2 Functionalized Indolizines Via Baylis-Hillman Reaction

Herein, we report a sustainable, rapid, and cost-effective methodology for the synthesis of 2-functionalized indolizines from pyridine-2-carboxaldehydes by coupling with α,β-unsaturated compounds via the Baylis-Hillman pathway followed by cyclization in one-pot using DBU as the organocatalyst "on-water" under microwave irradiation. The water as the medium played a pivotal role in achieving quick conversion to the products in just 1 min in good to high yields (up to 78%). The method is further validated on several 2-acylpyridines; however, in these cases a longer time (up to 1 h) was required for complete conversion due to steric bulk at the reaction center and 1,2-functionalized indolizines are obtained in similar yields (up to 74%). The substituent variation in pyridine and α,β-unsaturated compounds show negligible electronic effect and a diverse functional group tolerance is observed. Furthermore, the scalability of the method is studied at the gram-scale with representative examples, which afford products in comparable yields to that of the small-scale reactions. The present method tick multiple sustainability matrices like metal-free synthesis, water as reaction medium, cost-effectiveness, and low E-factor.

DFT investigations and molecular docking as potent inhibitors of SARS-CoV-2 main protease of 4-phenylpyrimidine

In this work, quantum chemical descriptors and a vibrational analysis of 4-Phenylpyrimidine (4-PPy) were also investigated. Through conformational analysis, the most stable conformer can be determined. The geometry of the molecular structure was optimized by using the density functional theory (DFT) at the B3LYP/6-311++G(d,p) level. The theoretically obtained FT-IR and FT-Raman spectral data agree with the experimental results. UV-Vis was done in the gas phase along with different solvents by the TD-DFT method and the PCM solvent model. Molecular electrostatic potential, natural bond orbital analysis, nonlinear optical properties, and global chemical reactivity parameters were described through the DFT method. Besides, the chemical implications of a molecule were explained using an electron localization function and a local orbital locator. We attempted to detect the antiviral activity of the 4-PPy compound by predicting molecular docking into coronavirus 2 (SARS-n-CoV-2) protein structures (6LU7, 6M03, and 6W63), because COVID-19 is known to have serious adverse effects in all areas of human life worldwide, and possible drugs need to be investigated for this. The results of the docking simulation demonstrate good affinities for binding to the receptors.

Cross-Coupling Reactions of 5-Bromo-1,2,3-triazine

An efficient Pd catalyzed cross-coupling method for 5-bromo-1,2,3-triazine is described. Optimization of the reaction conditions allowed for the preparation of a representative scope of (hetero)aryl-1,2,3-triazines (20 examples, up to 97% yield). The reaction scope was evaluated using a data science enabled boronic acid chemical space to assess the generality of the method. Additionally, diversification of the resulting products enabled the preparation of pyrimidines and pyridines in yields of up to 80% and in only two steps.

Discovery of 4-nitro-3-phenylisoxazole derivatives as potent antibacterial agents derived from the studies of [3 + 2] cycloaddition

Polysubstituted phenylisoxazoles were designed and synthesized to discover new antibacterial agents via [3 + 2] cycloaddition. Thirty-five compounds with a phenylisoxazole scaffold were characterized by NMR, HRMS, and X-ray techniques. After being evaluated against Xanthomonas oryzae (Xoo), Pseudomonas syringae (Psa), and Xanthomonas axonopodis (Xac), 4-nitro-3-phenylisoxazole derivatives were found to better antibacterial activities. Further studies have shown that the EC₅₀ values of these compounds were much better than that of the positive control, bismerthiazol.

Thirty-five compounds with phenylisoxazole scaffold were synthesized via [3+2] cycloaddition. After being evaluated against Xoo, Psa and Xac, 4-nitro-3-phenylisoxazole derivatives were found well antibacterial activities.

Synthesis and preliminary structure-activity relationship study of 3-methylquinazolinone derivatives as EGFR inhibitors with enhanced antiproliferative activities against tumour cells

In this paper, a set of 3-methylquniazolinone derivatives were designed, synthesised, and studied the preliminary structure-activity relationship for antiproliferative activities. All target compounds performed significantly inhibitory effects against wild type epidermal growth factor receptor tyrosine kinase (EGFRwt-TK) and tumour cells (A431, A549, MCF-7, and NCI-H1975). In particular, compound 4d 3-fluoro-N-(4-((3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)methoxy)phenyl)benzamide showed higher antiproliferative activities against all tumour cells than Gefitinib (IC50 of 3.48, 2.55, 0.87 and 6.42 μM, respectively). Furthermore, compound 4d could induce apoptosis of MCF-7 cells and arrest in G2/M phase at the tested concentration. Molecular docking and ADMET studies showed that compound 4d could closely form many hydrogen bonds with EGFRwt-TK. Therefore, compound 4d is potential to develop as novel anti-cancer drug.