Ultrasound Assisted One-Pot Synthesis of Novel 3-(Aryl)-5-((4-(phenyldiazenyl)phenoxy)methyl)isoxazolines in Water

In this work, we present an efficient one-pot method for the synthesis of three new azo-isoxazoline derivatives (4a–c) from aromatic aldehydes, hydroxylamine hydrochloride and 4-(allyloxy)azobenzene. Thus, the azo-isoxazoline derivatives (4a–c) were synthesized via 1,3-dipolar cycloaddition using sodium dichloroisocyanurate (SDIC) as an eco-friendly and inexpensive oxidizing agent under ultrasound cavitation in water as a green solvent. The desired compounds 4a–c were obtained in high to excellent yields of 75–90%

Ethyl 2-[(5Z)-5-(4-methoxybenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]acetate

In the title compound, C15H15NO5S, the benzene and heterocyclic rings are close to being coplanar [dihedral angle = 1.49 (6)°]. In the crystal, pairwise C—H...O hydrogen bonds form dimers, which are arranged into `stair-step' rows by way of C=O–π interactions between a carbonyl group and the benzene ring [O...π = 3.3837 (12) Å]

Ethyl 2-[(5Z)-5-(4-methylbenzylidene)-2,4-dioxo-1,3-thiazolidin-3-yl]acetate

In the title molecule, C15H15NO4S, the dihedral angle between the almost planar heterocyclic ring (r.m.s. deviation = 0.027 Å) and the benzene ring is 5.33 (8)°. The chain of the ester group adopts an extended conformation [C—O—C—C = −174.80 (14)°]. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds generate R22(10) loops and further such bonds connect the dimers into `stair-step' chains propagating in [100]

N′-Phenyl-N′-[3-(2,4,5-triphenyl-2,5-dihydro-1H-pyrazol-3-yl)quinoxalin-2-yl]benzohydrazide

The molecule of the title compound, C42H32N6O, is built up from one pyrazole ring linked to three phenyl rings and to an approximately planar [maximum deviation = 0.0455 (15) Å] quinoxaline system connected to a phenylbenzohydrazide group. The pyrazole ring assumes an envelope conformation, the C atom attached to the quinoxalin-3-yl ring system being the flap atom. The dihedral angle between the two phenyl rings of the phenylbenzohydrazide group is of 58.27 (9)°. The mean plane through the pyrazole ring is nearly perpendicular to the quinoxaline ring system and to the phenyl ring attached to the opposite side, forming dihedral angles of 82.58 (7) and 87.29 (9)°, respectively. An intramolecular C—H...O hydrogen bond is present. In the crystal, molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers, which are further connected by C—H...N hydrogen bonds into chains parallel to the b axis

Pharmacological Profile of Quinoxalinone

Quinoxalinone and its derivatives are used in organic synthesis for building natural and designed synthetic compounds and they have been frequently utilized as suitable skeletons for the design of biologically active compound. This review covers updated information on the most active quinoxalinone derivatives that have been reported to show considerable pharmacological actions such as antimicrobial, anti-inflammatory, antidiabetic, antiviral, antitumor, and antitubercular activity. It can act as an important tool for chemists to develop newer quinoxalinone derivatives that may prove to be better agents in terms of efficacy and safety

N′-[(1E)-4-Bromobenzylidene]-5-phenyl-1H-pyrazole-3-carbohydrazide

In the title compound, C17H13BrN4O, the dihedral angles between the pyrazole ring and the pedant phenyl and bromobenzene rings are 21.61 (11) and 28.09 (11)°, respectively. In the crystal, N—H...O hydrogen bonds link the molecules into [010] chains, which are reinforced by C—H...O interactions

Synthesis, X-ray, spectroscopy, molecular docking and DFT calculations of (E)-N'-(2,4-dichlorobenzylidene)-5-phenyl-1H-pyrazole-3-carbohydrazide

(E)-N'-(2,4-dichlorobenzylidene)-5-phenyl-1H-pyrazole-3-carbohydrazide (E-DPPC) has been synthesized and characterized by FT-IR, 1H-NMR, ESI-MS, and single-crystal X-ray diffraction. The structures and properties of this new pyrazole-3-carbohydrazide derivative were studied in gas phase and aqueous solution by using Functional hybrid B3LYP/6-311++G** calculations in gas phase and in aqueous solution to study. Two stable structures (C1 and C2) with similar energies were found in the PES. C2 evidence a higher dipole moment and a volume contraction in solution attributed to the presence of donors and acceptors H bonds. Besides, the changes in orientation and direction of dipole moment vector in solution are attributed to the hydration of E-DPPC with water molecules. The repulsion existent between the negative MK, Mulliken and NPA charges on the N12 and O15 atoms explain the diminishing of N12-C14-O15 angle from 123.77 ° in gas phase to 123.03 ° in solution. Nucleophilic sites are visibly observed on the acceptor H bonds groups (N10, O15 and N22 atoms) while on the N18-H21, N12-H13, C11-H23, C2-H3, C17-H20 bonds characteristics electrophilic sites were found, being the N18-H21 bond the most labile donor of H bond with the lowest MEP and bond order values. NBO calculations suggest that C2 is clearly most stable in solution than in gas phase. AIM studies show that C2 is stable in both media due to new H bonds formed. Harmonic force fields in both media were calculated together with the scaled force constants while the 102 vibration normal modes expected for C2 were completely assigned. The comparisons of experimental NMR and UV-visible spectra with the corresponding predicted evidence reasonable correlations. Docking results also displayed that E-DPPC possessed good binding profile against receptor molecule and interacted with core residues of target protein

Synthesis, crystal structure, DFT studies and biological activity of (Z)-3-(3-bromophenyl)-1-(1,5-dimethyl-1H-pyrazol-3-yl)-3-hydroxyprop-2-en-1-one

Abstract Background Nowadays, is emerging a new generation of highly promising inhibitors bearing the β-ketoenol functionality. The present work relates to the first synthesis, the structure determination, the DFT studies and the use of a new biomolecule designed with a β-ketoenol group bounded to a pyrazolic moiety. Result A novel β-ketoenol-pyrazole has been synthesized, well characterized and its structure was confirmed by single crystal X-ray diffraction. The electron densities and the HOMO–LUMO gap have been calculated using the DFT method with BLYP, PW91, PWC functionals and 6-31G* basis set. An evaluation of the molecule stability is provided by a NBO analysis and the calculated Fukui and Parr functions have been used to locate the reactive electrophile and nucleophile centers in the molecule. The synthesized compound, screened for its in vitro antifungal behavior against the Fusarium oxysporum f.sp. albedinis FAO fungal strains, shows a moderate activity with an inhibition percentage of 46%. The product was also tested against three bacterial strains (Escherichia coli, Bacillus subtilis and Micrococcus luteus), but no significant effect was observed against these organisms. Conclusions Density functional calculations are used to evaluate the HOMO–LUMO energy gap, the molecular electrostatic potential and to provide a natural bond orbital analysis. The measured antimicrobial activities encourage us to continue searching for other structures, likely to be good antifungal candidates