2899-28-7Relevant articles and documents
Solvent free three-component synthesis of 2,4,5-trisubstituted-1H-pyrrol-3-ol-type Compounds from L-tryptophan: DFT-B3LYP calculations for the reaction mechanism and 3H-pyrrol-3-one?1H-pyrrol-3-ol tautomeric equilibrium
Becerra, Lili Dahiana,Coy-Barrera, Ericsson,Quiroga, Diego
, (2020/10/12)
In this paper, we describe the solvent-free three-component synthesis of 2,4,5-trisubstituted-1H-pyrrol-3-ol-type compounds from L-tryptophan. The first step of the synthetic methodology involved the esterification of L-tryptophan in excellent yields (93–98%). Equimolar mixtures of alkyl 2-aminoesters, 1,3-dicarbonyl compounds, and potassium hydroxide (0.1 eq.) were heated under solvent-free conditions. The title compounds were obtained in moderate to good yields (45%–81%). Density functional theory using “Becke, 3-parameter, Lee–Yang–Parr” correlational functional (DFT-B3LYP) calculations were performed to understand the molecular stability of the synthesized compounds and the tautomeric equilibrium from 3H-pyrrol-3-one type intermediates to 1H-pyrrol-3-ol type aromatized rings.
Preparation method of tryptophan ester hydrochloride
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Paragraph 0045-0048, (2019/12/02)
The invention discloses a preparation method of tryptophan ester hydrochloride. The preparation method comprises the following steps: 1) reacting p-toluenesulfonyl chloride with tryptophan in alcoholto obtain a tryptophan ester hydrochloride crude product; and 2) purifying the crude product to obtain the tryptophan ester hydrochloride. According to the method, the p-toluenesulfonyl chloride and the lower alcohol which are available in the market and low in price are used as raw materials, reaction conditions are easy to implement, operation is easy, the cost is greatly reduced compared with other methods, the obtained product is high in purity and the method is suitable for large-scale industrial production.
Tryptophan ester hydrochloride preparation method
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Paragraph 0050; 0051, (2018/03/25)
The invention discloses a synthesizing method for tryptophan ester hydrochloride. The synthesizing method includes the steps that firstly, organic amine serves as catalysts, in proper solvents, tryptophan and hydrogen chloride generate tryptophan hydrochloride; secondly, the tryptophan hydrochloride and ester are esterified at the backflow temperature, generated water is taken away in an azeotropy mode, an esterification reaction is promoted, and after the reaction is completed, the tryptophan ester hydrochloride as the target product is obtained through postprocessing processes such as filtering, low-boiling-point substance low-pressure removing and recrystallization. Mother liquid obtained after recrystallization is repeatedly used indiscriminately, and the number of repeating times is larger than five. The synthesizing method has the advantages that the raw material cost is low, the conversion rate is high, postprocessing is simple, chlorinating agents such as thionyl chloride are not required, and three-waste discharging is less; the synthesizing method is suitable for industrial production.
Thermodynamic, kinetic and mechanistic approach to the corrosion inhibition of carbon steel by new synthesized amino acids-based surfactants as green inhibitors in neutral and alkaline aqueous media
Fawzy,Abdallah,Zaafarany,Ahmed,Althagafi
, p. 276 - 291 (2018/06/13)
The inhibiting power of three synthesized amino acids based-surfactant molecules, namely, sodium N-dodecyl asparagines (AS), sodium N-dodecylhistidine (HS) and sodium N-dodecyltryptophan (TS) on the dissolution of carbon steel was inspected in 0.5 M NaCl
Synthesis, spectroscopic characterization, and in vitro antibacterial evaluation of novel functionalized sulfamidocarbonyloxyphosphonates
Bouzina, Abdeslem,Bechlem, Khaoula,Berredjem, Hajira,Belhani, Billel,Becheker, Imène,Lebreton, Jacques,Le Borgne, Marc,Bouaziz, Zouhair,Marminon, Christelle,Berredjem, Malika
, p. 1 - 14 (2018/07/31)
Several new sulfamidocarbonyloxyphosphonates were prepared in two steps, namely carbamoylation and sulfamoylation, by using chlorosulfonyl isocyanate (CSI), α-hydroxyphosphonates, and various amino derivatives and related (primary or secondary amines, β-amino esters, and oxazolidin-2-ones). All structures were confirmed by 1H, 13C, and 31P NMR spectroscopy, IR spectroscopy, and mass spectroscopy, as well as elemental analysis. Eight compounds were evaluated for their in vitro antibacterial activity against four reference bacteria including Gram-positive Staphylococcus aureus (ATCC 25923), and Gram-negative Escherichia coli (ATCC 25922), Klebsiella pneumonia (ATCC 700603), Pseudomonas aeruginosa (ATCC 27853), in addition to three clinical strains of each studied bacterial species. Compounds 1a–7a and 1b showed significant antibacterial activity compared to sulfamethoxazole/trimethoprim, the reference drug used in this study.
Preparation of the MacMillan imidazolidinones
Samulis, Leopold,Tomkinson, Nicholas C.O.
experimental part, p. 4263 - 4267 (2011/06/26)
A general method for the preparation of the MacMillan imidazolidinones is described. Treatment of an α-amino amide with a carbonyl compound in refluxing chloroform in the presence of Yb(OTf)3 (1 mol %) provides convenient access to the corresponding imidazolidinones.
Mechanistic studies on the cis to trans epimerization of trisubstituted 1,2,3,4-tetrahydro-β-carbolines
Van Linn, Michael L.,Cook, James M.
supporting information; experimental part, p. 3587 - 3599 (2010/07/04)
Figure presented It is well-known that Nb-benzyltryptophan alkyl esters undergo the Pictet-Spengler reaction with aldehydes to furnish both cis- and trans-1,2,3,4-tetrahydro-β-carbolines, with the trans isomer predominating. Epimerization at C-1 took place under acidic conditions to produce, exclusively, the thermodynamically more stable trans diastereomer via internal asymmetric induction. Recent kinetic experiments provided insight into the cis to trans epimerization mechanism involved in the Pictet-Spengler reaction of 1,2,3-trisubsituted tetrahydro-β-carbolines. Since the epimerization reaction had been shown to be sensitive to electronic effects at C-1, the rate data for a series of 1-phenyl-substituted 1,2,3,4-tetrahydro- β-carbolines was investigated via a Hammett study. Analysis of the data supported the presence of a positively charged intermediate with a φ value of -1.4, although the existence of an iminium ion intermediate or a carbocationic intermediate could not be determined from this data alone. Analysis of the rate of epimerization demonstrated first-order kinetics with respect to TFA following the initial protonation of the substrate. This observation was consistent with the formation of a doubly protonated intermediate as the rate-determining step in the carbocation-mediated cis to trans epimerization process. In addition, the observed first-order rate dependence was inconsistent with the retro-Pictet-Spengler mechanism since protonation at the indole-2 position was not rate determining as demonstrated by kinetic isotope effects. Based on this kinetic data, the retro-Pictet-Spengler pathway was ruled out for the cis to trans epimerization of 1,2,3-trisubstituted 1,2,3,4-tetrahydro-β-carbolines, while the olefinic mechanism had been ruled out by experiments carried out in TFA-d.
Study of the cis to trans isomerization of 1-Phenyl-2,3-disubstituted tetrahydro-β-carbolines at C(1). Evidence for the carbocation-Mediated mechanism
Kumpaty, Hephzibah J.,Van Linn, Michael L.,Shahjahan Kabir,Holger Foersterling,Deschamps, Jeffrey R.,Cook, James M.
experimental part, p. 2771 - 2779 (2009/08/15)
The present study was undertaken to shed light on the mechanism of the epimerization of cis-1,2,3-trisubstituted tetrahydro-β-carbolines into the trans isomers via a potential carbocationic intermediate at C(1). In order to study the pathway involved in C
Brain-specific drug delivery
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, (2008/06/13)
The subject compounds, which are adapted for the site-specific/sustained delivery of centrally acting drug species to the brain, are: (a) compounds of the formula wherein [D] is a centrally acting drug species, and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier, with the proviso that when [DHC] is STR1 wherein R is lower alkyl or benzyl and [D] is a drug species containing a single NH2 or OH functional group, the single OH group when present being a primary or secondary OH group, said drug species being linked directly through said NH2 or OH function group to the carbonyl function of [DHC], then [D] must be other than a sympathetic stimulant, steroid sex hormone or long chain alkanol; and (b) non-toxic pharmaceutically acceptable salts of compounds of formula (I) wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier. The corresponding ionic pyridinium salt type drug/carrier entitles [D--QC]+ X- are also disclosed.
Sulfur and silicon-containing fatty acid amides
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, (2008/06/13)
Sulfur and silicon-containing amides, e.g. N-5-sila-3-thia-5,5-dimethyl-pentadecanoyl-1-phenyl-2-(4-methylphenyl)-ethylamine, are useful as anti-atherosclerotic agents. The amides are obtainable by acylation of a primary amine (the substituents on the amine being of the aralkyl phenyl, tryptophanyl, benzocycloalkyl-type) with a corresponding sulfur and silicon-containing carboxylic acid (or active form thereof).
