13227-01-5Relevant articles and documents
Mechanism of the Racemization of Amino Acids. Kinetics of Racemization of Arylglycines
Smith, Grant Gill,Sivakua, Thipamon
, p. 627 - 634 (1983)
In a study of the rates of racemization of substituted arylglycines at pH 10, the Hammett ? value was found to be surprisingly low, 1.15, suggesting a concerted reaction or charge stabilization in a manner other than by the substituent.The rate of methine hydrogen exchange was, however, the same as the rate of racemization, which argues against a concerted reaction mechanism.A pH profile study demonstrated that the most reactive species was the zwitterion +NH3CH(C6H5)CO2-> in basic media.The racemization reaction showed general-base catalysis when the buffer concentration was changed at constant ionic strength.Within the aryl series, the entropy of activation was more significant than the enthalpy of activation.The ΔS(excit.) ranged from -24.5 to +29.0 eu, while ΔH(excit.) values ranged from 19.9 to 20.4 kcal.Racemization of arylglycines followed reversible first-order kinetics similar to that found for aliphatic amino acids in solution.The extent of racemization was studied as a function of pH.The details of the mechanism of this reaction are presented in light of these data.
Synthesis of Unprotected 2-Arylglycines by Transamination of Arylglyoxylic Acids with 2-(2-Chlorophenyl)glycine
Inada, Haruki,Shibuya, Masatoshi,Yamamoto, Yoshihiko
, p. 11047 - 11059 (2020/10/12)
The transamination of α-keto acids with 2-phenylglycine is an effective methodology for directly synthesizing unprotected α-amino acids. However, the synthesis of 2-arylglycines by transamination is problematic because the corresponding products, 2-arylglycines, transaminate the starting arylglyoxylic acids. Herein, we demonstrate the use of commercially available l-2-(2-chlorophenyl)glycine as the nitrogen source in the transamination of arylglyoxylic acids, producing the corresponding 2-arylglycines without interference from the undesired self-transamination process.
Synthesis of new imidazolidin-2,4-dione and 2-thioxoimidazolidin-4-ones via C-phenylglycine derivatives
De Sousa Luis, Jose Alixandre,Barbosa Filho, Jose Maria,Lira, Bruno Freitas,Medeiros, Isac Almeida,De Morais, Liana Clebia Soares Lima,Dos Santos, Alexsandro Fernandes,De Oliveira, Cledualdo Soares,De Athayde-Filho, Petronio Filgueiras
experimental part, p. 128 - 137 (2010/05/18)
Hydantoins and their derivatives constitute a group of pharmaceutical compounds with anticonvulsant and antiarrhythmic properties, and are also used against diabetes. N-3 and C-5 substituted imidazolidines are examples of such products. As such, we have developed a synthesis of 2,4-dione and 2-thioxo-4-one imidazolidinic derivatives by reaction of amino acids with C-phenylglycine, phenyl isocyanate and phenyl isothiocyanate. Four amino-derivatives IG(1-4) and eight imidazolidinic derivatives, IM(1-8), were obtained in yields of 70-74%. The mass, infrared, 1H and 13C-NMR spectra of representative products are discussed.
Inhibitors of phenylalanine ammonialyase: 1-aminobenzylphosphonic acids substituted in the benzene ring
Zoń, Jerzy,Amrhein, Nikolaus,Gancarz, Roman
, p. 9 - 21 (2007/10/03)
Dextrorotatory 1-amino-3′,4′-dichlorobenzylphosphonic acid was found to be a potent inhibitor of the plant enzyme phenylalanine ammonia-lyase both in vitro and in vivo from among the ring-substituted 1-aminobenzylphosphonic acids and other analogues of phenylglycine. A structure activity relationship analysis of the results obtained permits predictions on the geometry of the pocket of the enzyme and is a basis in the strategy of better inhibitor synthesis.
