53848-16-1

Upstream product

• 97-51-8 5-Nitrosalicylaldehyde 
• 100-46-9 benzylamine 

Downstream Products

• 119578-69-7 bis(N-benzyl-5-nitro-salicylaldiminate) zinc(II) 
• 75830-38-5 N-(2-hydroxy-5-nitrobenzyl)benzylamine 
• 75830-08-9 Acetic acid 2-{[(2-amino-3-methyl-butyryl)-benzyl-amino]-methyl}-4-nitro-phenyl ester; hydrochloride 
• 75830-36-3 N-<(tert-butoxycarbonyl)-L-valinyl>-N-benzyl-N-(2-acetoxy-5-nitrobenzyl)amide 
• 75830-15-8 2-Acetylamino-N-benzyl-N-(2-hydroxy-5-nitro-benzyl)-3-methyl-butyramide 
• 75830-37-4 N-(2-hydroxy-5-nitrobenzyl)benzylamine*HCl 

Relevant academic research and scientific papers

NMR structural study of the prototropic equilibrium in solution of schiff bases as model compounds

An NMR titration method has been used to simultaneously measure the acid dissociation constant (pKa) and the intramolecular NHO prototropic constant δKNHO on a set of Schiff bases. The model compounds were synthesized from benzylamine and substituted ortho-hydroxyaldehydes, appropriately substituted with electron-donating and electron-withdrawing groups to modulate the acidity of the intramolecular NHO hydrogen bond. The structure in solution was established by 1H-, 13C- and 15N-NMR spectroscopy. The physicochemical parameters of the intramolecular NHO hydrogen bond (pKa, δKNHO and δδG°) were obtained from 1H-NMR titration data and pH measurements. The Henderson-Hasselbalch data analysis indicated that the systems are weakly acidic, and the predominant NHO equilibrium was established using Polster-Lachmann d-diagram analysis and Perrin model data linearization.

Hydrogen bonding in Schiff bases - NMR, structural and experimental charge density studies

A series of sixteen Schiff bases (derivatives of salicylaldehydes and aryl amines) was studied to reveal the influence of substituents and the length of the linker on the properties of the H-bonding formed. In theory, two groups of compounds, derivatives of 2-(2-hydroxybenzylidenoamine)phenol) and 2-hydroxy-N-(2-hydroxybenzylideno)benzylamine, can form different types of H-bonds using one or two hydroxyl groups present in the molecules. Two other groups of compounds, derivatives of 4-(2-hydroxybenzylidenoamine)phenol and N-(2-hydroxybenzyideno)benzylamine, can form only one type of H-bond. It was confirmed by 15N and 13C NMR experiments, that in all cases only traditional, H-bonded six-membered chelate rings were formed. The positions of the hydrogen atom in the rings depend on the substituent and phase. Generally, the OH H-bond form dominates in solution, with exception of the nitro derivatives, where the NH tautomer is present. In the solid state the tautomeric equilibrium is strongly shifted to the NH form. Only for the 5-Br derivative of one compound was the reverse relationship found. According to the results of experimental charge density investigations, two intramolecular H-bonds in the 5-methoxy derivative of 2-hydroxy-N-(2′-hydroxybenzylideno) benzylamine) differ significantly in terms of charge density properties. The intra- and intermolecular H-bonds formed by the deprotonated oxygen atom from 2-OH group are strong, with significant charge density concentration at the bond critical point and a straight, well-defined bond path, whereas the second intramolecular H-bond formed by the oxygen atom from the 2′-OH group is quite weak, with ca. five times smaller charge density concentration than in the previous case and a bent bond path. In terms of energy densities, the latter H-bond appears to be a non-bonding interaction, with total energy density being slightly positive. In terms of source contributions to the density at the H-bond critical point from the atoms involved, the intermolecular, linear H-bond is very strong and charge-assisted in the source function classification, the N(1)-H(1N)...O(1) H-bond is medium-strength, while the third H-bond is extremely weak.

Phosphatase inhibitors. III. Benzylaminophosphonic acids as potent inhibitors of human prostatic acid phosphatase

Further investigation of the structural requirements of a series of benzylphosphonic acid inhibitors of human prostatic acid phosphatase has led to the highly potent series of α-aminobenzylphosphonic acids. The α-benzylaminobenzylphosphonic acid, with an IC50 = 4 nM, exhibited a 3500-fold improvement in potency over the carbon analogue, α-phenylethyl. The enhanced potency may be due to a combination of four favorable interactions including those with the phosphate binding region, the presence the hydrophobic moieties of the benzylamino and phenylphosphonic acid, and a rigid conformer produced by an internal salt bridge between the phosphonate and the α-amino group. Replacement of the phosphonic acid moiety with a phosphinic or carboxylic acid as well as deletion of the benzyl substitution on the α-amino group led to great reductions in potency.

STRUCTURAL INFORMATION ON SOME BERYLLIUM(II) COMPLEXES OF N-ARALKYLSALICYLALDIMINES

A series of stable beryllium(II) complexes of newly synthesized N-aralkylsalicylaldimine Schiff bases has been prepared and characterized.Structures have been elucidated on the basis of analytical, conductance and IR and PMR spectral data.A tetrahedral symmetry has been proposed for all these complexes which are non-ionic.

Intramolecular O,N-Acyl Transfer via Cyclic Intermediates of Nine and Twelve Members. Models for Extensions of the Amine Capture Strategy for Peptide Synthesis

Rate constants are reported for intramolecular O,N-acyl-transfer reactions of 2-amino-N-benzyl-N-acetamides,2-amino-N-benzyl-N-(4-acetoxy-5-xanthyl)methylene>acetamide, ethyl N-(2-acetoxybenzyl)-2-aminoacetate, methyl N--2-aminoacetate and their alanine and valine analogues in acetonitrile, Me2SO, and other solvents.Synthesis of these substrates is described, and a novel two-step synthesis is reported of 4-hydroxy-5-formylxanthene from 2,3-diacetoxybenzaldehyde and 2-(isopropoxymethylene)cyclohexanon in 29percent yield.Facile intramolecular acyl transfer via cyclic intermediates of 9 and 12 members is described, and steric and solvent effects on rates of acyl transfer are reported for these processes and compared with those for other intra- and intermolecular acyl-transfer reactions.The significance of these results for amide formation by amine capture is discussed.