Khalid Karrouchi

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.

Synthesis, antioxidant and analgesic activities of Schiff bases of 4-amino-1,2,4-triazole derivatives containing a pyrazole moiety

A series of Schiff bases of 4-amino-1,2,4-triazole derivatives containing pyrazole (5a-h) were synthesized from condensation of 4-amino-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol (3) derivative with various aromatic aldehydes (4a-h). The structures of the synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, and mass spectrometry. All the synthesized compounds (5a-h) were screened for their in vivo analgesic and in vitro antioxidant activities revealing significant analgesic and antioxidant properties.

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

Crystal structure of N′-di­phenyl­methyl­idene-5-methyl-1H-pyrazole-3-carbo­hydrazide

In the title compound, C18H16N4O, the planes of the phenyl rings are approximately perpendicular to each other [dihedral angle = 78.07 (8)°] and form dihedral angles of 56.43 (8) and 24.59 (8)° with the pyrazole ring. In the crystal, molecules are linked by N—H⋯O hydrogen bonds to form one-dimensional chains parallel to the [010] direction.

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.

New Pyrazole-Hydrazone Derivatives: X-ray Analysis, Molecular Structure Investigation via Density Functional Theory (DFT) and Their High In-Situ Catecholase Activity

The development of low-cost catalytic systems that mimic the activity of tyrosinase enzymes (Catechol oxidase) is of great promise for future biochemistry technologic demands. Herein, we report the synthesis of new biomolecules systems based on hydrazone derivatives containing a pyrazole moiety (L1–L6) with superior catecholase activity. Crystal structures of L1 and L2 biomolecules were determined by X-ray single crystal diffraction (XRD). Optimized geometrical parameters were calculated by density functional theory (DFT) at B3LYP/6–31G (d, p) level and were found to be in good agreement with single crystal XRD data. Copper (II) complexes of the compounds (L1–L6), generated in-situ, were investigated for their catalytic activities towards the oxidation reaction of catechol to ortho-quinone with the atmospheric dioxygen, in an attempt to model the activity of the copper containing enzyme tyrosinase. The studies showed that the activities depend on four parameters: the nature of the ligand, the nature of counter anion, the nature of solvent and the concentration of ligand. The Cu(II)-ligands, given here, present the highest catalytic activity (72.920 μmol·L−1·min−1) among the catalysts recently reported in the existing literature.

Crystal structure of N′-(4-(dimethylamino)benzylidene)-5-phenyl-1H-pyrazole-3-carbohydrazide, C19H19N5O

Abstract C19H19N5O, triclinic, P1̅ (no. 2), a = 11.8865(6) Å, b = 12.6289(7) Å, c = 13.5579(7) Å, α = 74.552(2)°, β = 83.174(2)°, γ = 62.534(2)°, V = 1740.56(16) Å3, Z = 4, Rgt(F) = 0.0610, wRref(F2) = 0.1713, T = 100 K.

Crystal structure of N′-(4-methoxybenzylidene)-5-phenyl-1H-pyrazole-3-carbohydrazide, C18H16N4O2

Abstract C18H16N4O2, triclinic, P1̅ (no. 2), a = 10.9734(4) Å, b = 11.8835(5) Å, c = 13.0996(5) Å, α = 78.581(2)°, β = 78.542(1)°, γ = 83.725(2)°, V = 1636.68(11) Å3, Z = 4, Rgt(F) = 0.0439, wRref(F2) = 0.1182, T = 100 K.