40478-12-4Relevant academic research and scientific papers
Application of chiral triazole-substituted iodoarenes in the enantioselective construction of spirooxazolines
Abazid, Ayham H.,Nachtsheim, Boris J.
supporting information, p. 8822 - 8825 (2021/09/07)
A catalytic highly enantioselective synthesis of spirooxazolines is presented. Starting from readily available 2-naphthol-substituted benzamides and using catalytic amounts of a chiral triazole-substituted iodoarene catalyst, a variety of spirooxazolines
A convenient and clean synthesis of methylenebisamides and carbinolamides over zeolites in aqueous media
Mameda, Naresh,Marri, Mahender Reddy,Peraka, Swamy,Macharla, Arun Kumar,Kodumuri, Srujana,Chevella, Durgaiah,Naresh, Gutta,Nama, Narender
, p. 41 - 43 (2015/02/02)
A simple, efficient and environmentally benign protocol for the synthesis of methylenebisamides and carbinolamides in high yields from aromatic amides and formaldehyde in the presence of heterogeneous catalysts (Hβ and NaY zeolites) using water as a solvent is demonstrated. Moreover, the catalyst is recyclable and can be reused without significant loss in its catalytic activity.
Rate of formation of N-(hydroxymethyl)benzamide derivatives in water as a function of pH and their equilibrium constants
Ankem, Ramana V.,Murphy, John L.,Nagorski, Richard W.
supporting information; scheme or table, p. 6547 - 6549 (2009/04/05)
The third-order rate constants for the pH-dependent formation of the carbinolamides generated from the reaction of formaldehyde and benzamide, 4-chloro, 4-nitro, 4-methyl and 4-methoxybenzamide, are reported. The acid-catalyzed reaction was found to occur via rate-limiting proton transfer, whereas the hydroxide-dependent reaction occurred via a specific-base process. Coupling the rate constants for carbinolamide formation reported herein with the previously established rates for carbinolamide breakdown yielded equilibrium constants for the carbinolamides studied in water.
Amidates as leaving groups: Structure/reactivity correlation of the hydroxide-dependent E1cB-like breakdown of carbinolamides in aqueous solution
Tenn III, William J.,Murphy, John L.,Bim-Merle, Jessica K.,Brown, Jason A.,Junia, Adam J.,Price, Malea A.,Nagorski, Richard W.
, p. 6075 - 6083 (2008/02/10)
(Graph Presented) The kinetic study of the aqueous reaction, between pH 10 and 14, of eight N-(hydroxymethyl)benzamide derivatives in water at 25°C, I = 1.0 M (KCl), has been performed. In all cases, the reaction proceeds via a specific-base-catalyzed deprotonation of the hydroxyl group followed by rate-limiting breakdown of the alkoxide to form aldehyde and amidate (E1cB-like). Such a mechanism was supported by the lack of general buffer catalysis and the first-order dependence of the rate of reaction at low hydroxide concentrations and the transition to zero-order dependence on hydroxide at high concentration. A ρ-value of 0.67 was found for the Hammett correlation between the maximum rate for the hydroxide independent breakdown of the deprotonated carbinolamide (k1) and the substituent on the aromatic ring of the title compounds. Conversely, the substituents on the aromatic ring of the amide portion of the carbinolamide had only a small effect on the Ka of the hydroxyl group indicating that the amide group does not strongly transmit the electronic information of the substituents. These observations led to the conclusion that the major effect of electronic changes on the amide of carbinolamides is reflected in the nucleofugality of the amidate once the alkoxide is formed and not in the pKa of the hydroxyl group of the carbinolamide.
Solvent-free N-hydroxymethylation using formalin over basic alumina
Gupta, Rajive,Paul, Satya,Nanda, Puja
, p. 573 - 574 (2007/10/03)
A convenient and high yield method for N-hydroxymethylation of amines with formalin over basic alumina under solvent-free conditions with microwave heating is described.
Acyloxymethyl as a Drug Protecting Group. Kinetics and Mechanism of the Hydrolysis of N-Acyloxymethylbenzamides
Iley, Jim,Moreira, Rui,Rosa, Eduarda
, p. 563 - 570 (2007/10/02)
Acyloxymethyl derivatives of secondary and tertiary amides undergo hydrolysis via acid-catalysed, base-catalysed and pH-independent processes.The pH-independent pathway involves rate-limiting iminium ion formation and is characterised by the following: a Hammett ρ value for the substituent in the benzamide moiety of ca. -1.2 for both types of substrate; the absence of general-base or nucleophilic catalysis; a common benzoate ion effect; a solvent deuterium isotope effect, kobsH2O/kobsD2O, of ca. 1.6; Σ(excit.) values of -4 and -12 J k-1 mol-1 for secondary and tertiary substrates respectively; and higher reactivity of the tertiary amides over their secondary counterparts.The acid-catalysed process involves protonation of the substrate followed by iminium ion formation, and is characterised by the following: a Hammett ρ value of ca. -1.5 for the substitutent effect of the benzamide moiety; a solvent deuterium isotope effect of ca. 0.4; a monotonic rise in the pseudo-first-order rate constant kobs with increasing ; ΔS(excit.) values > 0 J K-1 mol-1; higher reactivity of the tertiary substrates over their secondary counterparts; and a value of 0.85 for the Bronsted coefficient, βlg, for the carboxylate nucleofuge.The base-catalysed hydrolysis of tertiary substrates involves normal ester hydrolysis via acyl-oxygen bond cleavage, and is characterised by a Hammett ρ value of +0.38, a solvent deuterium isotope effect, kOH-/kOD-, of 0.85, and a ΔS(excit.) balue of -96 J K-1 mol-1.The corressponding base-catalysed process for the secondary substrates involves imine formation via an E2 elimination reaction.The secondary acyloxymethylamides are some 7 * 104 times more reactive than their tertiary counterparts in the base-catalysed region.Hammett ρ values of +1.1 and +0.6 are obtained for the substituents in the base-catalysed region.Hammett ρ values of +1.1 and +0.6 are obtained for the substituents in the ester and amide moieties, respectively.Buffer catalysis is observed, and the value of ca. 0.5 for the Bronsted β coefficient identifies the amide proton as approximately 50percent transferred to the buffer species in the transition state.Heats of formation, ΔHf, calculated using the AM1 SCF MO package reveal that iminium ion formation is thermodynamically equi-energetic for cyclic and acyclic systems.Iminium ion formation from tertiary substrates is favoured by ca. 25 kJ mol-1 over the corresponding secondary analogues.
