114461-07-3Relevant academic research and scientific papers
A Concise Synthesis of Sterically Hindered 3-Amino-2-Oxindoles
O'Connor, Stephen J.,Liu, Zheng
, p. 2135 - 2138 (2007/10/03)
A new method for the synthesis of 3-alkyl-3-amino-2-oxindoles is reported. These compounds are prepared in a 3-step procedure using a base-mediated nucleophilic addition of benzylidene-imine protected α-aminoesters to 2-nitrofluorobenzene as the key step. The process provides a variety of 3-alkyl-3-amino-2-oxindole analogs in yields of 1-24%. Yields are highest with alanine, phenylalanine and 2-pyridylalanine as the amino acid starting materials, while 3-pyridylalanine and O-methyltyrosine are less efficiently arylated. Sterically hindered amino acids such as valine and phenylglycine are for all practical purposes, not substrates for the key nucleophilic substitution reaction. The resulting 3-alkyl-3-amino-2-oxindoles are important intermediates for the preparation of drug-like substances. The conversion of alanine ethyl ester to 3-amino-3-methyl-2-oxindole is described.
SOLID-LIQUID PHASE TRANSFER CATALYTIC SYNTHESIS OF α-AMINO ACID VIA ALKYLATION AND NUCLEOPHILIC ADDITION OF BENZALDEHYDE IMINES
Yaozhong, Jiang,Changyou, Zhou,Shengde, Wu,Daimo, Chen,Youan, Ma,Guilan, Liu
, p. 5343 - 5354 (2007/10/02)
A short, mild and efficient synthetic route of α-amino acid via alkylation, Michael addition and carbonyl addition as well as cycloaddition of aldimines derived from glycine and alanine esters with benzaldehyde under solid-liquid phase transfer catalytic condition has been studied.The key to solid-liquid phase transfer catalyzed reactions is the selection of a base for the various reactants.The yield is dependent on the base used.The results obtained using KOH, K2CO3 and Na2CO3 are discussed.The kinetics of solid-liquid PTC benzylation has been investigated and we propose a possible mechanism of solid-liquid PTC as an interface auto-catalytic procedure.The details of some syntheses of α-amino acids are presented.
