625111-97-9Relevant articles and documents
Preparation method of racemic ketoisoleucine calcium and intermediate thereof
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Paragraph 0030; 0032; 0034; 0036; 0038; 0040, (2021/12/07)
The invention relates to a preparation method of racemic ketoisoleucine calcium and an intermediate thereof, the method comprises the following steps: reacting hydantoin and butanone in ammonia water to obtain sec-butyl hydantoin, adding strong base for reaction, and obtaining racemic ketoisoleucine salt with high yield and high purity without complex post-treatment steps. Calcium racemization ketoisoleucine can be prepared by using the calcium racemization ketoisoleucine salt prepared by the method, high-yield and high-purity calcium racemization ketoisoleucine can be obtained, the reaction solvent can be recycled and reused, the method is green and environment-friendly, and the problem of pollution to the environment is solved.
Mechanochemical preparation of hydantoins from amino esters: Application to the synthesis of the antiepileptic drug phenytoin
Konnert, Laure,Reneaud, Benjamin,De Figueiredo, Renata Marcia,Campagne, Jean-Marc,Lamaty, Frdric,Martinez, Jean,Colacino, Evelina
, p. 10132 - 10142 (2015/02/19)
The eco-friendly preparation of 5- and 5,5-disubstituted hydantoins from various amino ester hydrochlorides and potassium cyanate in a planetary ball-mill is described. The one-pot/two-step protocol consisted in the formation of ureido ester intermediates, followed by a base-catalyzed cyclization to hydantoins. This easy-handling mechanochemical methodology was applied to a large variety of α- and β-amino esters, in smooth conditions, leading to hydantoins in good yields and with no need of purification steps. As an example, the methodology was applied to the "green" synthesis of the antiepileptic drug Phenytoin, with no use of any harmful organic solvent.
Dibutylphosphate (DBP) mediated synthesis of cyclic N,N′- disubstituted urea derivatives from amino esters: A comparative study
Agrawal, Sumit K.,Sathe, Manisha,Kaushik, M. P.,Halve, A. K.
, p. 5996 - 5999,4 (2020/08/20)
The N,N′-disubstituted urea derivatives such as amino acid hydantoins and dihydrouracil derivatives were prepared starting from natural and unnatural amino acid esters using dibutylphosphate (DBP). During the attempted synthesis of N-heterocycles with larger than six-membered rings containing the N,N′-disubstituted urea functionalities, three unexpected products namely squamolone, N-methyl pyrrolidine-2-one, and diketopiperazine were isolated.
Synthesis of 1S,5R- and 1R,5S-glycoluriles by diastereospecific α-ureidoalkylation of (S)/(R)-N-carbamoyl-α-amino acids with 4,5-dihydroxyimidazolidin-2-one
Chikunov, Il'ya E.,Kravchenko, Angelina N.,Belyakov, Pavel A.,Lyssenko, Konstantin A.,Baranov, Vladimir V.,Lebedev, Oleg V.,Makhova, Nina N.
, p. 253 - 255 (2007/10/03)
A diastereospecific method for the synthesis of individual enantiomers of 1S,5R- and 1R,5S-glycoluriles has been developed based on the α-ureidoalkylation of (S)/(R)-N-carbamoyl-α-amino acids with 4,5-dihydroxyimidazolidin-2-one.
Preparation of α-aminothioamides from aldehydes
Paventi, Martino,Edward, John T.
, p. 282 - 289 (2007/10/02)
The conversion of aldehydes into α-aminonitriles and thence into imidazolidin-4-thiones has been studied.Hydrolysis of the appropriate imidazolidin-4-thiones gave thioamides of nine naturally occuring α-amino acids.The possible pre-biotic significance of these compounds is discussed.
