23633-07-0Relevant academic research and scientific papers
Asymmetric chemoenzymatic synthesis of N-acetyl-α-amino esters based on lipase-catalyzed kinetic resolutions through interesterification reactions
Da Silva, Marcos Reinaldo,De Mattos, Marcos Carlos,De Oliveira, Maria Da Concei??o Ferreira,De Lemos, Telma Leda Gomes,Ricardo, Nágila Maria Pontes Silva,De Gonzalo, Gonzalo,Lavandera, Iván,Gotor-Fernández, Vicente,Gotor, Vicente
, p. 2264 - 2271 (2014/03/21)
Several phenylalanine analogs have been synthesized through a four-step route starting from easily available ethyl acetamidocyanoacetate. In a first reaction, and making use of phase transfer catalysts, this compound reacted with several alkyl halides, being benzyltributylammonium chloride identified as the best one for the production of a series of quaternary amino acids in moderate to excellent yields (52-95%). Then, the corresponding N-acetyl-phenylalanine methyl and allyl ester derivatives were obtained through acidic hydrolysis, esterification, and N-acetylation. Rhizomucor miehei lipase was found as a versatile enzyme for the resolution of these amino esters, finding the best results through interesterification reactions with butyl butyrate in acetonitrile. A great influence in the stereoselectivity was found depending on the chemical structure of the compound, achieving for the non- or para-substituted in the phenyl ring excellent stereoselectivities, being moderate for the meta-nitro derivative, while the ortho-nitro amino ester did not react.
Anthranilic acid based CCK1 receptor antagonists: Preliminary investigation on their second "touch point"
Varnavas, Antonio,Lassiani, Lucia,Valenta, Valentina,Mennuni, Laura,Makovec, Francesco,Hadjipavlou-Litina, Dimitra
, p. 563 - 581 (2007/10/03)
In this phase of structure-affinity relationship study of VL-0395, a new anthranilic acid based CCK1 selective antagonist, we propose a series of unnatural aminoacidic derivatives. The result of this work is the identification of a new CCK ligand, which possesses an affinity (IC50 = 35 nm) one order of magnitude greater than the lead and, as a general rule, it points out how the hypothesized receptorial pocket which accommodates the Phe residue allows much more structural modification than that interacting with the N-terminal group. Hence, the modification of the C-terminal pharmacophoric group of our lead VL-0395 can not only enhance the affinity of anthranilic acid derivatives but can modulate the selectivity for one CCK receptor subtype or afford mixed antagonists.
A crystallization-induced asymmetric transformation to prepare (R)-4- chlorophenylalanine methyl ester
Maryanoff, Cynthia A.,Scott, Lorraine,Shah, Rekha D.,Villani Jr., Frank J.
, p. 3247 - 3250 (2007/10/03)
A second order asymmetric transformation of racemic 4- chlorophenylalanine methyl ester was achieved via salt formation with (2S,3S)-(-)-tartaric acid in the presence of salicylaldehyde to afford the desired (R)-enantiomer of 4-chlorophenylalanine methyl ester in good yield and high enantiomeric purity.
Synthesis and antitumor activity of platinum(II) complexes containing substituted ethylenediamine ligands
Brunner, Henri,Hankofer, Peter,Holzinger, Ulrich,Treittinger, Barbara,Schoenenberger, Helmut
, p. 35 - 44 (2007/10/02)
The synthesis of substituted ethylenediamines, their reactions with K2PtCl4 to give the dichloroplatinum(II) complexes, and the exchange of the chloro ligands for other leaving groups are described.The new compounds have been tested as antitumor agents both in vitro using the hormone independent human mammary carcinoma cell line MDA-MB 231 as well as in vivo using the lymphocytic P388 leukemia of the CD2F1-mouse.In the P388 test, 53 of the 55 tested complexes fulfill the minimum activity of 125percent T/C required for a substance to be active.
