Discovery of N-(3-{4-[(3-fluorobenzyl)oxy]phenoxy}propyl)-2-pyridin-4-ylacetamide as a potent and selective reverse NCX inhibitor

In the setting of heart failure and myocardial ischemia-reperfusion, the sodium-calcium exchanger (NCX) can lead to calcium overload, which is responsible for contractile dysfunction and arrhythmia. NCX is an attractive target for treatment in heart failure and myocardial ischemia-reperfusion. We have designed and synthesized a series of benzyloxyphenyl derivatives based on compound 3. These derivatives have been evaluated for their inhibitory activity against both the reverse and forward modes of NCX. We have discovered a novel potent and selective reverse NCX inhibitor (12) with an IC50 value of 0.085 microM against reverse NCX.     

4-(Pyrrolidinyl)methoxybenzoic acid derivatives as a potent, orally active VLA-4 antagonist

A novel series of benzoic acid derivatives as VLA-4 antagonists were synthesized. Optimization, focusing on activity and lipophilicity needed for cell permeability, resulted in the identification of 15b and 15e with good activity (IC50 = 1.6 nM each) and moderate lipophilicity (Log D = 2.0, 1.8). Furthermore, 15e demonstrated efficacy in murine asthma model by an oral dose of 30 mg/kg.     

Unprecedented syntheses of 1,5-difluoropentan-3-amine and 4-fluoro-2-(2-fluoroethyl)butan-1-amine

Herein, we report two synthetically useful and high yielding routes to so far unknown branched γ,γ′- and δ,δ′-difluoroalkylamines that can be of interest as building-blocks for medicinal chemistry programs.     

Simple and efficient production of (Z)-4-hydroxytamoxifen, a potent estrogen receptor modulator

A McMurry coupling reaction and selective crystallization were used to develop a simple and efficient two-step synthesis of (Z)-4-hydroxytamoxifen (2a). This compound is an active metabolite of tamoxifen, a selective estrogen receptor (ER) modulator widely used to treat breast cancer. The synthesis employed 1,1-bis(4-hydroxyphenyl)-2-phenylbut-1-ene (1) as a useful building block.     

Synthesis,Crystal Structure and Antitumor Activity of(E)-N-(4-Fluorobenzylidene)-3-(methylthio)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-4-amine

The crystal structure of the title compound(E)-N-(4-fluorobenzylidene)-3-(methylthio)-5-(3,4,5-trimethoxyphenyl)-4 H-1,2,4-triazol-4-amine(C_(19)H_(19)FN_4O_3S,Mr = 402.44) was synthesized,and its structure was characterized by 1 H-NMR,13 C-NMR,ESI-MS and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P1 with a = 9.228(13),b = 10.364(14),c = 10.641(14) ?,α = 85.323(3),β = 75.172(2),γ = 80.903(3)°,μ = 0.20 mm~(-1),M_r = 402.44,V = 970.64(10) ?~3,Z = 2,D_c = 1.377 g/cm~3,F(000) = 420,R = 0.0484 and wR = 0.1474 for 3181 observed reflections with I 2σ(I).In addition,the preliminary bioassay indicated that the title compound 5 exhibits better inhibitory activity against Hela than 5-fluorouracil.     

MgF(3)(-) as a transition state analog of phosphoryl transfer

The formation of complexes between small G proteins and certain of their effectors can be facilitated by aluminum fluorides. Solution studies suggest that magnesium may be able to replace aluminum in such complexes. We have determined the crystal structure of RhoA.GDP bound to RhoGAP in the presence of Mg(2+) and F(-) but without Al(3+). The metallofluoride adopts a trigonal planar arrangement instead of the square planar structure of AlF(4)(-). We have confirmed that these crystals contain magnesium and not aluminum by proton-induced X-ray emission spectroscopy. The structure adopted by GDP.MgF(-) possesses the stereochemistry and approximate charge expected for the transition state. We suggest that MgF3(-) may be the reagent of choice for studying phosphoryl transfer reactions.     

Synthesis, molecular conformation, vibrational and electronic transition, isometric chemical shift, polarizability and hyperpolarizability analysis of 3-(4-methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile: a combined experimental and theoretical analysis

This work presents the synthesis and characterization of a novel compound, 3-(4-Methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile (abbreviated as 3-(4MP)-2-(4-NP)-AN, C₁₆H₁₂N₂O₃). The spectroscopic properties of the compound were examined by FT-IR, UV–vis and NMR (¹H and ¹³C) techniques. FT-IR spectrum in solid state was observed in the region 4000–400 cm⁻¹. The UV–vis absorption spectrum of the compound which dissolved in chloroform was recorded in the range of 200–800 nm. The ¹H and ¹³C NMR spectra were recorded in CDCl₃ solution. To determine lowest-energy molecular conformation of the title molecule, the selected torsion angle is varied every 10° and molecular energy profile is calculated from 0° to 360°. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP/6-31G(d,p) basis set. The dipole moment, linear polarizability and first hyperpolarizability values were also computed using the same basis set. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The HOMO and LUMO analysis were used to elucidate information regarding charge transfer within the molecule. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. Comparison of the calculated frequencies, NMR chemical shifts, absorption wavelengths with the experimental values revealed that DFT and TD-DFT method produce good results. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the title compound can be used as a good nonlinear optical material. The thermodynamic properties of the studied compound at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperatures.     

Microwave-assisted synthesis and antibacterial activity of derivatives of 3-[1-(4-fluorobenzyl)-1H-indol-3-yl]-5-(4-fluorobenzylthio)-4H-1,2,4-triazol-4-amine

Herein, an excellent method for the synthesis of twelve novel Schiff base derivatives containing indole and triazole assisted by microwave irradiation is reported. Compared with the conventional method, the yields increased from 59–84 % to 85–96 % and the reaction time was reduced from 24–30 h to 4–8 min. Moreover, all series of the newly synthesized Schiff bases were evaluated for their antibacterial activity. The values of minimum inhibitory concentration (MIC) and IC50 indicated that many target compounds possessed excellent antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis.     

4-(Phenyldiazenyl)naphthalen-1-amine and its hydrochloride

The crystal structures of 4-(phenyl­diazenyl)­naphthalen-1-amine, C₁₆H₁₃N₃, (I), and its hydro­chloride, (4-amino­naph­thal­en-1-yl)­phenyl­diazenium chloride, C₁₆H₁₄­N₃⁺·­Cl⁻, (II), have been determined from X-ray single-crystal and powder data, respectively. The effect of the crystal environment on the molecular electronic structure was analysed on the AM1 level. One of the two symmetry-independent mol­ecules in (I) is involved in intermolecular hydrogen bonding, so that its dipole moment is twice as large as that of the other mol­ecule. The cations in (II) form stacks along [100], with the Cl⁻ anions forming hydrogen bonds to all three H atoms attached to N atoms.     

9-(4-Bromophenyl)-9-fluorenyl as a safety-catch nitrogen protecting group

[reaction: see text] The 9-(4-bromophenyl)-9-fluorenyl (BrPhF) group has been developed as a novel safety-catch amine protection. This relatively acid-stable protecting group can be successfully activated by palladium-catalyzed cross-coupling reaction of the aryl bromide with morpholine and then cleaved effectively under mild conditions using dichloroacetic acid and triethylsilane. Complementary conditions are reported for selective removal of the BrPhF group in the presence of tert-butyl esters and carbamates as well as deprotection of tert-butyl esters and carbamates in the presence of BrPhF amines.     

Spectroscopic characterization,X-ray structure and DFT studies on 4-[3-(2,5-dimethylphenyl)-3-methylcyclobutyl]-N-methylthiazol-2-amine

The titled molecule 4-[3-(2,5-dimethylphenyl)-3-methylcyclobutyl]-N-methylthiazol-2-amine (C₁₇H₂₂N₂S) is synthesized and characterized by ¹H NMR, ¹³C NMR, IR, and X-ray single crystal determination. The compound crystallizes in the monoclinic space group P2_1/c with a = 6.3972(4) Å, b = 9.4988(6) Å, c = 26.016(2) Å and β = 93.496(7)°. In addition to the molecular geometry from the X-ray determination, vibrational frequencies and gauge, including the atomic orbital (GIAO), ¹H and ¹³C NMR chemical shift values of the titled compound in the ground state are calculated using the density functional (B3LYP) method with 6-31G(d), 6-31++G(d,p) and 6-311+G(2d,p) basis sets. The calculated results show that the optimized geometries can well reproduce the crystal structure. Moreover, the theoretical vibrational frequencies and chemical shift values show good agreement with the experimental values. The predicted nonlinear optical properties of the titled compound are greater than those of urea. DFT calculations of the molecular electrostatic potentials and frontier molecular orbitals of the titled compound are carried out at the B3LYP/6-31G(d) level of theory.     

3R,4R-dihydroxy-L-proline: a potent and specific β-D-glucuronidase inhibitor

The title compound, a naturally-occurring amino acid found in virotoxins, competitively inhibits bovine β-D-glucuronidase but does not affect other glycosidases.     

Synthesis and structure of 4-[(4-Nitro-1,2,5-oxadiazol-3-yl)-NNO-azoxyl]-1, 2,5-oxadiazol-3-amine

The synthesis of the energetic compound 4-[(4-nitro-1,2,5-oxadiazol-3-yl)-NNO-azoxyl]-1,2,5-oxadiazol-3-amine (3) was achieved in two steps from diaminofurazan (1). Compound 3 was characterized by X-ray diffraction. From the X-ray structure a bifurcated intramolecular H bond between O(2)-H(2)-N(4) was observed. In addition, intramolecular H bonding was observed between H(1) and N(7) of an adjacent molecule. One molecule of ethanol and one-half molecule of water per molecule of3 was observed in the crystal lattice. However, no H bonding was observed between the solvent molecules and3 in the crystal lattice. Despite the presence of solvent in the crystal lattice,3 was found to have a high crystal density (d=1.856 g/cm³).     

QSAR analyses of 3-(4-benzylpiperidin-1-yl)-N-phenylpropylamine derivatives as potent CCR5 antagonists

CCR5 receptor binding affinity of a series of 3-(4-benzylpiperidin-1-yl)propylamine congeners was subjected to QSAR study using the linear free energy related (LFER) model of Hansch. Appropriate indicator variables encoding different group contributions and different physicochemical variables such as hydrophobicity (pi), electronic (Hammett sigma), and steric (molar refractivity, STERIMOL values) parameters of phenyl ring substituents of the compounds were used as predictor variables. The Hansch analysis explores the importance of the lipophilicity and electron-donating substituents for the binding affinity. However, this method could not give more insight into the structure-activity relationships because of the diverse molecular features in the data set. 3D-QSAR analyses of the same data set using Molecular Shape Analysis (MSA), Receptor Surface Analysis (RSA), and Molecular Field Analysis (MFA) techniques were also performed. The best model with acceptable statistical quality was derived from the MSA, which showed the importance of the relative negative charge (RNCG): substituents with a high RNCG value have more binding affinity than the unsubstituted piperidine and phenyl (R1 position) congeners. The relative negative charge surface area (RNCS) is detrimental (e.g. R2 = 3,4-Cl2) for the activity. An increase in the length of the molecule in the Z dimension (Lz) is conducive (e.g. R3 = sulfonylmorpholino), while an increase in the area of the molecular shadow in the XZ plane (Sxz) is detrimental (e.g. R1 = N-c-hexylmethyl-5-oxopyrrolidin-3-yl) for the binding affinity. The presence of a chiral center makes the molecule less active (e.g. R1 = N-methyl-5-oxopyrrolidin-3-yl). An increase in the van der Waals area, the molecular volume, and the difference between the volume of the individual molecule and the shape reference compound are conducive (e.g. R3 = (CH3)2NSO2-) for the binding affinity. Substituents with higher JursFPSA_2 values (fractional charged partial surface area) like the N-methylsulfonylpiperidin-4-yl (R1 position) group have better binding affinity than the substituents such as 4-chlorophenylamino (R1 position). Unsubstituted piperidines (R1 position) with less JursFNSA_1 values have lower binding affinity than the 4-chlorophenyl substituted compounds. The MFA derived equation shows interaction energies at different grid points, while the RSA model shows the importance of hydrophobicity and charge at different regions of the molecules. The models were validated through the leave-one-out, leave-15%-out, and leave-25%-out cross-validation techniques. The developed models were also subjected to a randomization test (99% confidence level). Although the MSA derived models had excellent statistical qualities both for the training as well as test sets, RSA and MFA results for the test sets are not comparable statistically with the MSA derived models.     

A very concise synthesis of a potent N-(1,3-thiazol-2-yl)pyridin-2-amine KDR kinase inhibitor

A very concise synthesis of a potent KDR kinase inhibitor 1 is described. The synthesis features an exceedingly efficient one-pot preparation of the aminothiazole 6 followed by Pd-Xantphos catalyzed cross-coupling with chloropyridine aldehyde 11. Reductive amination of the resulting aldehyde 10 with the piperazine fragment 9 afforded the final product.     

Antibacterial potential of N-(2-furylmethylidene)-1, 3, 4-thiadiazole-2-amine: Experimental and theoretical investigations

Recently, a lot of interest has been attributed to the Schiff base compound because of its wide range of biological activities which include: antibacterial, antifungal, antima larial, including; antiproliferative, antiviral, and antipyretic. In this research work, N-(2-furylmethylidene)-1, 3, 4-thiadiazole- 2-amine gotten from o-phenylenediamine and 5- methoxysalicaldehyde was produced and characterized using UV–Visible, FT-IR, ¹H NMR, ¹³C NMR, and GC-MS along with molecular modeling using density functional theory (DFT) and molecular docking approach. The results obtained indicated that the Schiff base exhibited antimicrobial action against all the tested microbes except Candidaalbicans isolate, which exhibited zero diameter zone of inhibition. The theoretical investigations of the synthesized compounds were computed applying density functional theory at the B3LYP/6–31++G (d, p) level of theory and in silico molecular docking simulation. In comparing binding affinity energies and binding poses of the studied compound and the standard drug (ampicillin), the deduction that the molecular docking analysis results are in good agreement with in vitro analysis of the synthesized compounds can be made.