329-71-5Relevant articles and documents
Reactivity of α-amino acids in the N-acylation with benzoic acid esters in aqueous dioxane
Ishkulova,Oparina,Kochetova,Kustova,Kalinina,Kuritsin
experimental part, p. 964 - 967 (2011/01/07)
The effect of the nitro group as a substituent in the phenoxide part of phenyl benzoate on the rate of N-acylation of glycine, L-proline,and L-valine in the water (40 wt %)-dioxane solvent was studied. The activation parameters of glycine reactions with the esters were measured. The existence of compensation effect and the linear relation of the logarithms of the acylation constants to the Hammett constants were revealed. The energy of the LUMO of esters can serve as the descriptors of the easters reactivity. Pleiades Publishing, Ltd., 2010.
Associative and Dissociative Pathways in the Alkaline Hydrolysis of Aryl 2-Hydroxycinnamates
Cevasco, Giorgio,Thea, Sergio
, p. 70 - 73 (2007/10/02)
Aryl 2-hydroxycinnamate esters hydrolyze in alkaline solutions (20percent dioxane-water v/v) obeying the rate law kobs = ka + kb/(1 + aH/Ka), where Ka is the ionization constant of the hydroxy group of the ester and kb is the second-order rate constant for the attack of hydroxide ion on the ionized ester.Kinetic data and activation parameters for the hydrolysis of the 2,4-dinitrophenyl ester show that the mechanism giving rise to the ka term cannot be a simple BAc2 type process and suggest the occurrence of a E1cB mechanism involving an "extended" o-oxoketene intermediate.The Broensted plot of the apparent second-order rate constante (kaKa/kw) versus the pK of the leaving group indicates that the reaction mechanism changes from E1cB to BAc2 for esters with leaving groups having pK higher than about 6.
Synthese von Di- und Tri(o-phenylendiamin)-Liganden
Hahn, Ekkehardt F.,Dittler-Klingemann, Andreas
, p. 779 - 782 (2007/10/02)
The o-phenylenediamine ligand trisamine, TRIPACEN (4) and bisamine, DIPACEN (8) are obtained by Williamson coupling of the potassium salt of 2,3-dinitrophenole (1) to tris(3-chlorpropyl)amine (2) or benzylbis(3-chlorpropyl)amine (5), respectively, followed by reduction of the nitro functions with Sn/HCl or Pd(OH)2/H2.