5513-38-2Relevant academic research and scientific papers
Preparation of a novel silica gel-adsorbed Br?nsted acid catalyst for the solvent-free esterification of bromoacetic acid with benzyl alcohol
Funabiki, Kazumasa,Komeda, Takuya,Sakaida, Yuta,Kubota, Yasuhiro,Matsui, Masaki
, p. 116 - 120 (2013/02/23)
A new bifunctional Br?nsted acid catalyst that contains two sulfo groups was prepared. The adsorption of this new bifunctional Br?nsted acid catalyst on silica gel made it possible to be reused 10 times without a loss of catalytic activity in the solvent-free esterification of bromoacetic acid with an equiv. of benzyl alcohol without the formation of dibenzyl ether.
Polymers from amino acids: Development of dual ester-urethane melt condensation approach and mechanistic aspects
Anantharaj,Jayakannan
experimental part, p. 2446 - 2455 (2012/10/08)
A new dual ester-urethane melt condensation methodology for biological monomers-amino acids was developed to synthesize new classes of thermoplastic polymers under eco-friendly and solvent-free polymerization approach. Naturally abundant l-amino acids were converted into dual functional ester-urethane monomers by tailor-made synthetic approach. Direct polycondensation of these amino acid monomers with commercial diols under melt condition produced high molecular weight poly(ester-urethane)s. The occurrence of the dual ester-urethane process and the structure of the new poly(ester-urethane)s were confirmed by 1H and 13C NMR. The new dual ester-urethane condensation approach was demonstrated for variety of amino acids: glycine, β-alanine, l-alanine, l-leucine, l-valine, and l-phenylalanine. MALDI-TOF-MS end group analysis confirmed that the amino acid monomers were thermally stable under the melt polymerization condition. The mechanism of melt process and the kinetics of the polycondensation were studied by model reactions and it was found that the amino acid monomer was very special in the sense that their ester and urethane functionality could be selectively reacted by polymerization temperature or catalyst. The new polymers were self-organized as β-sheet in aqueous or organic solvents and their thermal properties such as glass transition temperature and crystallinity could be readily varied using different l-amino acid monomers or diols in the feed. Thus, the current investigation opens up new platform of research activates for making thermally stable and renewable engineering thermoplastics from natural resource amino acids.
Transesterification of α-amino esters catalyzed by a tetranuclear zinc cluster: Zn4(OCOCF3)6O
Maegawa, Yusuke,Agura, Kazushi,Hayashi, Yukiko,Ohshima, Takashi,Mashima, Kazushi
supporting information; experimental part, p. 137 - 141 (2012/02/03)
Transesterification of amino acid ester derivatives was developed using a tetranuclear zinc cluster, Zn4(OCOCF3)6O, as the catalyst. Because the reaction conditions were very mild, a variety of N-protective groups and functional groups on side chains were tolerated. Georg Thieme Verlag Stuttgart. New York.
Catalyst and solvent-free amidation of inactive esters of N-protected amino acids
Nadimpally, Krishna Chaitanya,Thalluri, Kishore,Palakurthy, Nani Babu,Saha, Abhijit,Mandal, Bhubaneswar
supporting information; experimental part, p. 2579 - 2582 (2011/06/21)
A catalyst free procedure for the preparation of amides from inactive esters of N-protected amino acids and various amines is demonstrated under mild reaction conditions. Our effort to recover excess amine and generated alcohol is an approach towards environment friendly and cost effective synthesis under easy operational conditions.
Transesterification of various methyl esters under mild conditions catalyzed by tetranuclear zinc cluster
Iwasaki, Takanori,Maegawa, Yusuke,Hayashi, Yukiko,Ohshima, Takashi,Mashima, Kazushi
, p. 5147 - 5150 (2008/09/21)
(Chemical Equation Presented) A new catalytic transesterification promoted by a tetranuclear zinc cluster was developed. The mild reaction conditions enabled the reactions of various functionalized substrates to proceed in good to high yield. A large-scale reaction under solvent-free conditions proceeded with a low E-factor value (0.66), indicating the high environmental and economical advantage of the present catalysis.
Broadening of the substrate tolerance of α-chymotrypsin by using the carbamoylmethyl ester as an acyl donor in kinetically controlled peptide synthesis
Miyazawa, Toshifumi,Tanaka, Kayoko,Ensatsu, Eiichi,Yanagihara, Ryoji,Yamada, Takashi
, p. 87 - 93 (2007/10/03)
In the kinetically controlled approach of peptide synthesis mediated by α-chymotrypsin, the broadening of the protease's substrate tolerance is achieved by switching the acyl donor from the conventional methyl ester to the carbamoylmethyl ester. Thus, as a typical example, the extremely low coupling efficiency obtained by employing the methyl ester of an inherently poor amino acid substrate, Ala, is significantly improved by the use of this particular ester. Its ameliorating effect is observed also in the couplings of other amino acid residues such as Gly and Ser as carboxy components.
N-(benzyloxycarbonyl)glycine esters and amides as new anticonvulsants
Geurts, Muriel,Poupaert, Jacques H.,Scriba, Gerhard K. E.,Lambert, Didier M.
, p. 24 - 30 (2007/10/03)
Glycine is a small neutral amino acid exhibiting weak anticonvulsant activities in vivo. Recently, studies have demonstrated that N- (benzyloxycarbonyl)glycine (1) antagonized seizures superior to glycine in addition to activity in the maximal electroshock (MES) test, a convulsive model where glycine is inactive. In the present study a series of ester and amide derivatives of 1 as well as esters of N-(3-phenylpropanoyl)glycine (5) have been prepared. The compounds were evaluated in the MES test as well as in several chemically induced seizure models. Among the derivatives investigated, N-(benzyloxycarbonyl)glycine benzylamide (16) was the most potent compound exhibiting an anticonvulsant activity in the MES test comparable to the drug phenytoin. Median effective doses (ED50) of 4.8 and 11.6 mg/kg were determined at 30 min and 3 h after ip administration, respectively. Compound 16 also effectively suppressed tonic seizures in different chemically induced models such as the strychnine, 3- mercaptopropionic acid, and pentylenetetrazole tests. Moreover, the compound studied here did not show acute neurotoxicity in the rotorod test up to a dose of 150 mg/kg. It is concluded that N-(benzyloxycarbonyl)glycine amides, especially 16, are potent anticonvulsant agents.
Peptide Synthesis in Aqueous Solution. V. Properties and Reactivities of (p-Hydroxyphenyl)benzylmethylsulfonium Salts for Direct Benzyl Esterification of N-Acylpeptides
Nakata, Takashi,Nakatani, Masaru,Takahashi, Masatoshi,Okai, Jiro,Kawaoka, Yoshiaki,Kouge, Katsushige,Okai, Hideo
, p. 1099 - 1106 (2007/10/03)
Some (p-hydroxyphenyl)benzylmethylsulfonium salts were prepared. These compounds generated a benzyl cation and converted not only N-acylamino acids but also N-acylpeptides into their corresponding benzyl esters without causing the racemization.
