An improved and practical synthesis of 5,5-dimethyl-3-(2-propoxy)-4-(4-methanesulfonylphenyl)-2-(5H)-furanone (DFP—a selective inhibitor of cyclooxygenase-2)

One pot multi-component synthesis of novel functionalized pyrazolo furan-2(5H)-one derivatives: in vitro, DFT, molecular docking, and pharmacophore studies, as coronavirus inhibitors

New and facile one-pot approach for the syntheses of 12 derivatives of 3,5-disubstituted furane-2(5H)-one (4a-l) from easily available starting materials. The suitable synthetic procedures for selective synthesis of diverse furane-2(5H)-one derivatives were achieved via multi-component condensation of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde (1), pyruvic acid and different aromatic amines 3a-l in good to high yields and short reaction time by refluxing in acetic acid as well as obtained by another method (method B) when unsaturated arylidene pyruvic acid 6 was refluxed with different aromatic amines in acetic acid but in smaller yield than method A. Structures of the prepared compounds were elucidated by elemental analysis and spectral data as mass, IR, 1H-NMR and 13C-NMR spectroscopy. The antiviral efficacy of compounds 4a-l against SARS-CoV-2 was evaluated using the MTT assay. It was demonstrated that synthetic compounds 4c-e and 4h-j have a potent and selective inhibitory effect on SARS-CoV-2, a strain obtained from Egyptian patients. We utilized density-functional theory (DFT) analyses to deduce the molecular structures and topologies of the more energetic molecules. Molecular docking studies were performed against the SARS-CoV-2 main protease (PDB ID: 6Y84) and the SARS-CoV-2 Nsp9 RNA binding protein (PDB ID: 6W4B) to study the binding mechanism, non-bonding interactions, and binding affinity. Lastly, a hypothetical pharmacophore model was constructed by applying the Molecular Operating Environment (MOE) tool and eleven pharmaceuticals with proven antiviral activity.

Catalyst-Free Multicomponent Cyclopolymerizations of Diisocyanides, Activated Alkynes, and 1,4-Dibromo-2,3-Butanedione: a Facile Strategy toward Functional Polyiminofurans Containing Bromomethyl Groups

Polymers containing iminofuran (PIFs) are rarely reported due to the lack of simple and effective synthesis methods. In this work, a novel multicomponent cyclopolymerization (MCCP) of diisocyanides, activated alkynes, and 1,4-dibromo-2,3-butanedione using catalyst-free one-pot reactions under mild conditions to prepare PIFs containing bromomethyl groups is reported. PIFs with good solubility and thermal stability are obtained with high M_w s (up to 19 600) and good yields (up to 89.5%) under optimized polymerization conditions. The structure of the PIFs is characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. The photophysical properties indicate that polymers P1a2b3 and P1c2b3 have cluster-triggered emission characteristics. Thin films made from PIFs quickly degrade under UV irradiation. Moreover, the obtained polymers are decorated with bromomethyl and carboxylate groups in the side chain, which can be postfunctionalized to prepare multifunctional materials, such as star branched polymers and biomedical carrier materials. Thus, this work not only enriches the field of polymerization based on isocyanates and activated alkynes but also provides a facile strategy toward functional iminofuran polymers.

Synthesis and biological activities of novel trifluoromethylpyridine amide derivatives containing sulfur moieties

A series of trifluoromethylpyridine amide derivatives containing sulfur moieties (thioether, sulfone and sulfoxide) was designed and synthesized. Their antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo), Ralstonia solanacearum (R. solanacearum) and insecticidal activities against P. xylostella were evaluated. Notably, the half-maximal effective concentration (EC50) value of sulfone-containing compound F10 is 83 mg L-1 against Xoo, which is better than that of commercial thiodiazole copper (97 mg L-1) and bismerthiazol (112 mg L-1). Thioether-containing compounds E1, E3, E5, E6, E10, E11 and E13 showed much higher activities against R. solanacearum with the EC50 value from 40 to 78 mg L-1, which are much lower than that of thiodiazole copper (87 mg L-1) and bismerthiazol (124 mg L-1). Generally, most of the sulfone-containing compounds and sulfoxide-containing compounds showed higher activities against Xoo than that of the corresponding thioether-containing compound, but most of the thioether-containing compounds contributed higher antibacterial activities against R. solanacearum. Furthermore, title compounds E3, E11, E24 and G2 showed good insecticidal activities of 75%, 70%, 70% and 75%, respectively.

Synthesis of stable isotope-labelled firocoxib

Firocoxib (ML-1,785,713) is a nonsteroidal, potent, and selective COX-2 inhibitor, approved for the control of pain and inflammation associated with osteoarthritis in dogs and horses, as well as to control postoperative pain and inflammation in dogs. We employed a six-step synthesis to prepare firocoxib-[13 C6 ] in an overall yield of 35% from the commercially available bromobenzene-[13 C6 ]. The synthetic route involved the preparation of the key intermediate phenyl-13 C6 -methyl sulfide using cesium carbonate and S-methylthiourea sulfate under transition-metal free conditions. A two-step preparation of firocoxib-[13 C,2 H3 ] via the sulfinic acid derivative of firocoxib and methyl iodide-[13 C,2 H3 ] using the procedure of Gauthier and Yoshikawa was first undertaken. However, the deuterium atoms of the methyl sulfone undergo extensive exchange in aqueous media even at neutral pH. The isotope-labelled firocoxib is intended as an internal standard for bioanalyses of firocoxib from biological matrices.

A Study on the Kinetics and Mechanism of the One-Pot Formation of 3,4,5-Substituted Furan-2(5H)-Ones in the Presence of Lactic Acid: Effect of Different Substituents

The kinetics of the reaction between para-substituted anilines and dimethyl acetylenedicarboxylate (DMAD) with derivatives of benzaldehyde for the one-pot formation of 3,4,5-substituted furan-2(5 H)-ones in the presence of lactic acid as a catalyst have been studied spectrophotometrically at different temperatures. A mechanism involving four steps was proposed for the reactions, all of which followed second-order kinetics. The partial orders with respect to substituted aniline and DMAD were one and one and the reactions revealed zero-order kinetics for benzaldehyde and its derivatives. Changing of substituents on benzaldehyde left rates of reaction unaffected. However, various substituents on aniline showed that para electron-withdrawing groups decreased the rate of reaction. According to investigation of an isokinetic relationship, a common mechanism exists for all studied substituents and a general mechanism can be formulated. Kinetic values ( k and Ea) and associated activation parameters (Δ G‡, Δ S‡ and Δ H‡) of the reactions were determined.

Selective synthesis of mono- and bis-butenolide α-aminomethyl adducts

The selective installation of α-methylamine residues at the butenolide core is described using α-bromomethylene-γ-butenolide and primary as well as secondary amines in methanol at 0 °C. The preparation of mono- and bis-butenolide α-adducts is described. Bis-γ-butenolide adducts as well as mono α-aminomethyl-γ-butenolides can be selectively obtained depending on the nature of the reacting primary amine. In contrast, the use of secondary amines allows two different pathways leading either to the expected amino derivatives or to the formation of a C-O bond.

Effect of different substituents on the one-pot formation of 3,4,5-substituted furan-2(5H)-ones: a kinetics and mechanism study

This work focused on the effects of temperature and different para-substituted anilines on the activation parameters and kinetics of the synthesis reaction of 3,4,5-substituted furan-2(5H)-ones which were studied spectrally at different temperatures in formic acid.