Revisiting aryl amidine synthesis using metal amide and/or ammonia gas: Novel molecules and their biological evaluation

Amidines, due to their unique biocompatibility and desirable physical characteristics, have been the functionality of choice as a scaffold for large number of drug synthesis. But still synthesis of amidines in the presence of other active functional groups or pharmacophore, remained a challenge. In this work, a simple and reliable protocol for conversion of nitrile-amide to unsubstituted amidine–amide is developed using metal amide and/or ammonia gas. The scope and efficiency of this synthetic strategy are demonstrated on several substrates which differ in functional groups will be discussed. In this process, 10 novel aryl amidines in good yields (upto 85%) were synthesized. Biological evaluation revealed that compound 4-(aminoiminomethyl)-N-(2-furanyl methyl) benzamide (IC₅₀?=?9?µM) and 4-(aminoiminomethyl)-N-(3-pyridinylmethyl) benzamide (73.36% growth inhibition) showed moderate efficacy for cancer cells.     

Two New Insecticidal Amide Dimers from Fruits of Piper nigrum Linn.

The methanolic extract of dried ground seeds of Piper nigrum Linn . afforded fourteen compounds, of which thirteen were amides, including two new isomeric insecticidal amides, pipsaeedine ( 1 ) and pipbinine ( 2 ), along with eleven known amides and piptaline; (this is the first report of isolation of these compounds from this plant). The structures of 1 and 2 have been elucidated as (E,E)‐1‐[(E)‐5‐(7‐{6‐[5‐(piperidin‐1‐yl)‐5‐oxopent‐3‐enyl]‐1,3‐benzodioxol‐4‐yl}‐1,3‐benzodioxol‐5‐yl)‐1‐oxopenta‐2,4‐dienyl]piperidine and (E,E)‐1‐[(E)‐5‐(4‐{6‐[5(piperidin‐1‐yl)‐5‐oxopent‐3‐enyl]‐1,3‐benzodioxol‐4‐yl}‐1,3‐benzodioxol‐5‐yl)‐1‐oxopenta‐2,4‐dienyl]piperidine, respectively, through extensive 1D‐ and 2D‐NMR spectral studies, while the known constituents have been identified through comparison of their spectral data with those reported in the literature. Compounds 1 and 2 exhibited toxicities of 45.0 and 40.0 ppm, respectively, against fourth instar larvae of Aedes aegypti Liston.     

Measurements of mode field diameter and effective area of photonic crystal fibers by far-field scanning technique

We have demonstrated that the correction factor k _n = A _eff/(πw ²), where ω = MFD/2 (MFD: mode field diameter), is above 1.20 for photonic crystal fibers (PCFs) with structural parameters in the range of d/Λ ≅ 0.40 to 0.90 (d/Λ ratio of hole diameter d and pitch Λ). By using the far-field scanning (FFS) technique and the finite difference method, the results of experimental measurements and numerical simulations differed by only 0.9 to 3.0% for two types of PCFs. The finding that k _n ≠ 1.0 for PCFs indicates that their electrical field distribution is non-Gaussian and cannot be determined by assuming a conventional step-index distribution for PCFs. It was also found that the ITU-T Petermann II definition is the most suitable for MFD measurements of PCFs with non-Gaussian distribution.     

Structural studies of a novel bioactive benzophenone derivative: (4-Chloro-2-hydroxy-phenyl)-phenyl-methanone

The title compound (4-Chloro-2-hydroxy-phenyl)-phenyl-methanone was synthesized and the product obtained was characterized by spectroscopic techniques, and finally the structure was confirmed by X-ray diffraction studies. The compound crystallizes in the orthorhombic crystal system with the space group Pbca with unit cell parameters, a = 14.0359(5) Å, b = 6.8084(3) Å, c = 23.1097(8) Å, and Z = 4. The structure exhibits an intramolecular hydrogen bond which closes an S(6) ring. No directional interactions beyond the van der Waals packing contacts were identified in the crystal structure.     

Reactivities of osmium (VIII) towards some aldoses,amino sugars,and methylated sugars in alkaline medium

The kinetics of oxidation of some aldoses, amino sugars and methylated sugars by osmium (VIII) have been studied spectrophotometrically in alkaline medium. The reactions are first‐order with respect to both [sugar]≤9.0×10⁻³ mol dm⁻³ and [OH⁻]≤10.0×10⁻² mol dm⁻³ but tends toward zero order with respect to each at higher concentration. Activation parameters of the reactions have been calculated and plausible reaction mechanisms have been suggested. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 477–483, 1999     

Highly stereoselective synthesis of furano-oxepanes: intramolecular nitrone cycloaddition (INC) reactions on sugar derived 2-substituted allylic ethers

The stereoselective synthesis of furano-oxepanes has been achieved from sugar ethers by an intramolecular nitrone cycloaddition (INC) reaction. The substitution at the 2-position of the allylic group aided in the exclusive formation of oxepanes.