Monther A. Khanfar

A New Eudesmane Type Sesquiterpene from Inula Viscosa

Investigation of Inula viscosa of Jordanian origin afforded the new sesquiterpene 1 g -hydroxyilicic acid in addition to the known 2 g -hydroxyilicic acid.

Three new seco-ursadiene triterpenoids from Salvia syriaca.

Three new seco-ursadiene triterpenoids 1–3 together with 11 known compounds were isolated from Salvia syriaca of Jordanian origin. The compounds were identified by using NMR spectroscopy including extensive 2D NMR experiments and mass spectrometry. The structure of compound 3 was confirmed by X-ray crystallography, and the information thus obtained was used to confirm the stereochemistry of compounds 1 and 2. This is the second report of 17,22-seco-17(28),12-ursadien-22-oic acids.

High throughput synthesis of pyrazolopyrimidines via copper- catalysed cyclization and x-ray study

A rapid and easy high-yielding synthesis of pyrazolopyrimidinones in the presensce of copper chloride is described. To fully confirm the structure of a Viagra® intermediate, the X-Ray structure of 5-(2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydropyrazolo[4,3-d]pyrimidin-7-one (2a) was determined.

trans-Dichlorido(2,2-dimethyl­propane-1,3-diamine)­bis­(triphenyl­phosphane)ruthenium(II)

In the title compound, [RuCl2(C5H14N2)(C18H15P)2], the RuII atom is six-coordinated, forming a slightly distorted octahedral geometry, with two chloride ions in an axial arrangement, and two P atoms of two triphenylphosphane and two chelating N atoms of the bidentate 2,2-dimethylpropane-1,3-diamine ligand located in the equatorial plane. The average Ru—P, Ru—N and Ru—Cl bond lengths are 2.325 (18), 2.1845 (7) and 2.4123 (12) Å, respectively.

Synthesis of Some Ethyl 3-(Aryldiazenyl)-7-oxo-dihydropyrido[ 2,3-f]quinoxaline-8-carboxylates

Ethyl 7,8-diamino-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate (6) and its free acid 7 are prepared by chemical reduction of the respective 7-azido-8-nitroquinoline 5. Consecutive nucleophilic addition and cyclocondensation reactions of 6 with α-acetyl-N-arylhydrazonoyl chlorides 8a - c in ethanol and triethylamine are site-selective and yield the corresponding 3-(aryldiazinyl)- 2-methylpyrido[2,3- f ]quinoxalines 10a - c. Analytical and spectral (IR, MS, NMR) data of 6, 7, and 10a - c are in conformity with the assigned structures.

Synthesis, Characterization, Crystal Structure, and DFT Study of a New Square Planar Cu(II) Complex Containing Bulky Adamantane Ligand

A copper complex with square planar geometry, [(L)CuBr2] (1), (L = N′-(furan-2-ylmethylene)adamantne-1-carbohydrazide) has been synthesized and characterized by Fourier transfer infrared (FTIR) spectroscopy, elemental analysis, mass spectrometry, and single crystal X-ray diffraction. The crystal of 1 is solved as monoclinic, space group P21/m with unit cell parameters: a = 10.8030(8), b = 6.6115(8), c = 12.1264(12) Å, β = 101.124(8)°, V = 849.84(15) Å3, Z = 2, and R1 = 0.0751 with wR2 = 0.1581 (I > 2 σ). The structure of 1 shows intramolecular hydrogen bonding between the N–H and the furan oxygen which stabilizes the configuration of the complex. Furthermore, inside the lattice there are other weak interactions between bromo ligands and the ligand L. DFT calculations where performed to study the stability of this geometry.

Synthesis and antibacterial activity of N1-(carbazol-3-yl)amidrazones incorporating piperazines and related congeners

Abstract A selected set of N1-(4-chloro-9-ethylcarbazol-3-yl)amidrazones (7a–n) has been synthesized by reacting the respective hydrazonoyl chloride 5 derived from 3-amino-9-ethylcarbazole (3), with an appropriate sec-cyclic amine (6a–n) in ethanol in the presence of triethylamine. Unexpectedly, aromatic ring chlorination occurred at C-4 of 3 during its conversion to 6 as evidenced by analytical and spectral data and further confirmed by single crystal X-ray structure determination of the amidrazone 7n. Compounds 7a–n were tested for their in vitro antibacterial activity. Among the tested bacterial strains, methicillin-resistant Staphylococcus aureus was the most susceptible to 7f and Bacillus cereus to 7b both with a minimum inhibitory concentration value of 1.56 µg mL−1. Compounds 7c, 7f, and 7h could be useful as lead structures for further development of new antibacterial agents against Gram-positive and Gram-negative pathogens.

Evidences for Chelating Complexes of Lithium with Phenylphosphinic and Phenylphosphonic Acids: A Spectroscopic and DFT Study

Abstract Lithium complexes were prepared with phenylphosphinic and phenylphosphonic acids. The complexes were studied in the solid state using Fourier transform infrared spectroscopy spectroscopy and in solution (methanol) using 1H, 13C, and 31P Nuclear magnetic resonance spectroscopy (NMR) spectroscopy; the most preferred structures of the complexes were determined by density functional theory (DFT) computational method. Although methanol has a strong solvation effect on lithium ions and ligands, which causes dissociation of the complexes, significant changes of the NMR spectra of the complexes (relative to those of the free ligands) were observed. The new spectroscopic results indicate the presence of the phenylphosphinic acid tautomer (I: C6H5PH(˭O)OH) rather than that of phenyl-phosphorous acid (II: C6H5P(OH)2) in deuterated methanol showing PH/PD exchange. On the other hand, tautomer I predominates in the complex with lithium without showing PH/PD exchange. The DFT calculations predict that tautomer I is the preferred structure in the case of free ligand and lithium complex. The absence of a PH/PD exchange in the complex is due to the formation of a chelating complex, rather than of a simple salt between lithium ion and the two oxygen atoms of I, which prevent tautomerization of I into II. DFT calculations support the formation of lithium chelating complexes. The lithium ion was found to affect the spectroscopic properties of phenylphosphinic acid more dramatically than those of phenylphosphonic acid. GRAPHICAL ABSTRACT

2-(4-Methyl-phen-yl)quinoline-4-carb-oxy-lic acid.

In the title compound, C17H13NO2, the dihedral angle between the plane of the carboxy group and the quinoline mean plane is 45.05 (13)°, and that between the toluene ring mean plane and the quinoline mean plane is 25.29 (7)°. In the crystal, molecules are linked via O—H⋯.N hydrogen bonds, forming chains propagating along the b-axis direction. These chain are linked via C—H⋯O interactions, forming two-dimensional networks lying parallel to the ab plane.

Metal-assisted Oxidative Cyclization of Arylamidrazones II [1]. Novel Synthesis of 1,4-Diaryl[1,2,4]triazino[6,5-h]quinolines

New model 1,2,4-triazino[6,5-h]quinolines 8a - c are prepared by oxidative cyclization of the respective N-(quinolin-8-yl)amidrazone precursors 7a - c using copper(II) chloride. Interestingly, the cyclized products 8a - c were found to be arylated at N1 position. Analytical and spectral (MS, NMR) data of the title products are in compliance with the allocated structures.