Simple, Efficient, and Selective Synthesis of Phthaloylserine and Phthaloylthreonine

2015 ◽  
Vol 1088 ◽  
pp. 363-366
Author(s):  
Yu Ting Liu ◽  
Si Meng Song ◽  
Da Wei Yin ◽  
Dan Chen
Keyword(s):  
Amino Acids ◽  
Phthalic Anhydride ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Synthetic Method ◽  
Selective Synthesis ◽  
Protection Method ◽  
Amino Protection

An amino protection method was developed in which phthalic anhydride was used as the amino protection group, N,N-dimethylformamide (DMF) as solvent, L-threonine and L-serine with hydroxyl groups in side chain as the protected amino acids.The structures of products were confirmed by IR、1H NMR and 13C NMR. It is an efficient and simple protection method of amino acids with a hydroxyl group in the side chain.In addition, the synthetic method avoids the side reaction and significantly improves reaction yields(over 90%).

scholarly journals Synthesis and biotical activity of bacterial cellulose 6-(2-phthalimidoethanesulfonate)

2020 ◽  
Vol 61 (2) ◽  
pp. 29-36
Author(s):  
Zoya P. Belousova ◽  
Keyword(s):  
Bacterial Cellulose ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Cellulose Derivatives ◽  
Wound Surface ◽  
Reaction Products ◽  
Absorption Bands ◽  
Hydroxymethyl Group ◽  
Antibacterial And Antifungal

Bacterial cellulose obtained by culturing Gluconacetobacter sucrofermentans in HS environment was converted to sulfonate derivatives using methane-, toluene- and 2-phthalimidoethanesulfonic acids in pyridine. When the ratio of the starting reagents is 1 : 1, the modification of bacterial cellulose according to the primary hydroxyl group of glucopyranose fragments is most likely. The formation of 6-substituted bacterial cellulose derivatives was observed in the reaction mixture. The IR spectra of the reaction products contain absorption bands, which are specific for (O–SO2) group in the region 1377-1338 cm−1 (as), 1178-1154 cm−1 (s), fragments of the corresponding sulfonic acids, as well as free hydroxyl groups of glucopyranose in the region 3495-3382 cm−1. Bacterial cellulose 2-phthalimidoethanesulfonate was dissolved in pyridine. After drying with a desiccant in a desiccator, it turned into a dense transparent film of brown color. The increased molecular film allows to explain the side reaction occurring between the oxo group and fragments of one of the chains of modified cellulose and the non-substituted hydroxymethyl group. The IR spectrum of bacterial cellulose 6-(2-phthalimidoethanesulfonate) contains absorption bands in the region 1711 cm−1, which are specific for (Ar–CO–O) group, and absorption bands in the region 1618 cm−1, which prove the presence of (CO–NH) group. In order to impart antibiotic properties to the bacterial cellulose 6-(2-phthalimido-ethanesulfonate) film, it was physically modified with clotrimazole. The obtained experimental data showed that the films subjected to treatment with a 1% solution of clotrimazole have antibacterial and antifungal effects and prevent the growth of pathogenic microbiota on the wound surface. The exit rates of clotrimazole from the bacterial cellulose 6-(2-phthalimidoethanesulfonate) film and from the pure bacterial cellulose film differed, but only slightly. 2-Phthalimidoethanesulfonate bacterial cellulose films can be used to form composites of effective wound covering, since in addition to the unique properties of bacterial cellulose itself (low allergenicity and adhesion to the wound surface, high hygroscopicity) they will have a regenerating effect.

Newly Synthesized Branch-type Aromatic Oxadiazole Polymer and Binary Fluorescence Patterning on its Film

2007 ◽  
Vol 19 (5-6) ◽  
pp. 531-540 ◽  
Author(s):  
Moon Soo Choi ◽  
Hyung Jun Kim ◽  
Taek Seung Lee ◽  
Won Seok Lyoo
Keyword(s):  
Coupling Reaction ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Aromatic Side Chain ◽  
Suzuki Coupling Reaction ◽  
Color Changes ◽  
Fluorescence Color ◽  
Before And After ◽  
Photochemical Cleavage

Aromatic side-chain oxadiazole polymer linked with 9,9'-dioctylfluorene was successfully synthesized via Suzuki coupling reaction. Hydroxyphenyl group was attached in the 2-position of the oxadiazole unit in the polymer side chain to control the optical properties of the polymer. We confirmed the presence of the t-butoxycarbonyl group on the hydroxyl group using thermogravimetric analysis, which was incorporated to avoid side reaction during polymerization. We also performed the simple and easy fabrication method for the dual fluorescence image using photochemical cleavage of the t-butoxycarbonyl group from the polymer to induce fluorescence color changes before and after UV irradiation.

Convenient preparation of a β-O-4-type lignin model trimer via KOH-catalyzed hydroxymethylation and a new protection method

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Maarit Lahtinen ◽  
Anssi Haikarainen ◽  
Jussi Sipilä
Keyword(s):  
Model Compound ◽  
Catalytic Amount ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Chemical Behavior ◽  
Model Compounds ◽  
Protection Method ◽  
Convenient Synthesis ◽  
Lignin Model ◽  
Convenient Preparation

Abstract Lignin, as the second most abundant biopolymer on earth, is one of the targets for plant biorefinery studies. Its complex chemical behavior is frequently studied by dimeric, trimeric, etc. model compounds, preferably with a β-O-4-type structure. In the present study, a convenient synthesis of a β-O-4-type trimeric model compound possessing a free syringylic hydroxyl has been investigated. Two key modifications were in focus: (1) Protection of the aliphatic hydroxyl groups of the starting phenolic dimer prior to the SN2 displacement reaction before introducing the syringylic moiety with 2,2-dimethoxypropane. (2) The hydroxymethylation step to introduce the full side chain moiety. When this reaction was performed in dioxane/water in the presence of a catalytic amount of KOH instead of K2CO3, the formation of a side product via dehydration was markedly reduced. In addition, a convenient method for introducing an α,β-epoxide structure in acetophenone is recommended.

Reaction of Alantolactone, an Allergenic Sesquiterpene Lactone, with some Amino Acids. Resultant Loss of Immunologic Reactivity

1974 ◽  
Vol 52 (7) ◽  
pp. 575-581 ◽  
Author(s):  
G. Dupuis ◽  
J. C. Mitchell ◽  
G. H. N. Towers
Keyword(s):  
Amino Acids ◽  
Contact Dermatitis ◽  
Sesquiterpene Lactone ◽  
Sesquiterpene Lactones ◽  
Sulfhydryl Group ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Amino Group ◽  
Michael Type Addition ◽  
Methylene Group

A study of the reaction of a hapten, alantolactone, with some amino acids is reported. Previously, we have reported than an α-methylene group attached to the γ-lactone is the immunologic requisite of alantolactone and some other sesquiterpene lactones. Such a group is known to be capable of undergoing "Michael-type addition" with the sulfhydryl group of cysteine. We confirm this finding and report that alantolactone can also undergo addition with the imidazole group of histidine and with the ε-amino group of lysine, but not with the guanido group of arginine, the hydroxyl group of serine, or the thio ether function of methionine. We selected these amino acids for further study because of their nucleophilic side chain. Samples of alantolactone that have undergone such addition no longer produce allergic eczematous contact dermatitis, as measured by patch test.

scholarly journals A convenient synthesis of new NSAID esters containing amino acid, urea and amide moieties

2013 ◽  
Vol 63 (3) ◽  
pp. 409-418 ◽  
Author(s):  
Ivana Perković ◽  
Zrinka Rajić Džolić ◽  
Branka Zorc
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Residue ◽  
Acid Chloride ◽  
Amino Acid Derivatives ◽  
Hydroxyl Groups ◽  
Synthetic Method ◽  
Convenient Synthesis ◽  
Preparation Step ◽  
Solvent Free Reaction

Abstract A convenient synthetic method for the preparation of novel NSAID twin esters 6a-i containing amino acid residue, urea and amide moieties has been developed. The synthetic pathway applied for the preparation of target compounds and key intermediates 1-benzotriazolecarboxylic acid chloride (1), NSAID benzotriazolides 2a-c and N-(1-benzotriazolecarbonyl)-amino acids 3a-d involved benzotriazole as a synthetic auxiliary. The final preparation step of esters 6a-i included the solvent-free reaction of compounds 2a-c with amino acid derivatives 5a-g, bearing two hydroxyl groups, one at each terminal, beside urea and amide functionalities.

scholarly journals Theoretical Study of 2-(Trifluoromethyl)phenothiazine Derivatives with Two Hydroxyl Groups in the Side Chain-DFT and QTAIM Computations

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5242
Author(s):  
Andrzej Poła ◽  
Anna Palko-Łabuz ◽  
Kamila Środa-Pomianek
Keyword(s):  
Quantum Chemical ◽  
Biological Effects ◽  
Chemical Properties ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Dissociation Enthalpy ◽  
Wide Range ◽  
Thermochemical Parameters ◽  
Intramolecular Hydrogen

Phenothiazines are known as synthetic antipsychotic drugs that exhibit a wide range of biological effects. Their properties result from the structure and variability of substituents in the heterocyclic system. It is known that different quantum chemical properties have a significant impact on drug behavior in the biological systems. Thus, due to the diversity in the chemical structure of phenothiazines as well as other drugs containing heterocyclic systems, quantum chemical calculations provide valuable methods in predicting their activity. In our study, DFT computations were applied to show some thermochemical parameters (bond dissociation enthalpy—BDE, ionization potential—IP, proton dissociation enthalpy—PDE, proton affinity—PA, and electrontransfer enthalpy—ETE) describing the process of releasing the hydrogen/proton from the hydroxyl group in the side chain of four 2-(trifluoromethyl)phenothiazine (TFMP) derivatives and fluphenazine (FLU). Additional theoretical analysis was carried out based on QTAIM theory. The results allowed theoretical determination of the ability of compounds to scavenge free radicals. In addition, the intramolecular hydrogen bond (H-bond) between the H-atom of the hydroxyl group and the N-atom located in the side chain of the investigated compounds has been identified and characterized.

Studies on biliary excretion in the rabbit II. The relationship between the chemical structure of certain natural or synthetic pentacyclic triterpenes and their icterogenic activity. Part 1: The substituents on carbon atoms 3, 17, 22 and 24

1963 ◽  
Vol 157 (969) ◽  
pp. 473-491 ◽  
Keyword(s):  
Bile Flow ◽  
Chemical Structure ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Pentacyclic Triterpene ◽  
Triterpene Acid ◽  
Pentacyclic Triterpenes ◽  
Bilirubin Excretion ◽  
The Relationship

Considerable interest has been aroused by the use of the pentacyclic triterpene acid, icterogenin, in studies associated with bilirubin excretion and the genesis of icterus of the intrahepatic cholestasis type. This compound, which produces within a few hours after administration to sheep and rabbits a very marked decline in bile flow and the amount of bilirubin excreted hourly without any histological damage to the liver parenchyma visible in the ordinary light microscope, has proved to be very useful in the study of the South African ovine photosensitization disease known as 'geeldikkop’ (‘yellow thick head’). In connexion with research on this disease, a study of the relationship between the chemical structure of the pentacyclic triterpenes and their icterogenic activity is in progress. The first part of this work dealing with certain structural variations in triterpenes of the oleanane and 24-noroleanane (hedragane) series is reported in this paper. Assays are recorded of sixteen of these compounds and some of their derivatives for such activity, using a modification of the rabbit test described in the first paper of this series (Heikel, Knight, Rimington, Ritchie & Williams 1960). Four new icterogenic agents are discussed, namely: 22 β -angeloyloxyoleanolic acid, 22 β -angeloyloxyhedragolic acid, 22 β -angeloyloxy-24-hydroxyoleanolic acid and 22 β -angeloyloxy-24-oxo-oleanonic acid. The first two mentioned compounds are extremely active, their potency far surpassing that of icterogenin. Icterogenic activity of these acids appears, so far, to be based upon the presence of a β -equatorially orientated hydroxyl group at C(3) or a hydroxyl at C(24) and a 22 β -angeloyl side-chain on the triterpene molecule. Stereoisomer specificity is shown in respect of icterogenicity by these compounds since the epimers of two of these substances carrying α -axially orientated hydroxyls at C(3) have been shown to have no such effect on bile flow or bilirubin excretion. Removal of the angelic acid side-chain, substitution of the hydroxyl groups or replacement of these with a ketone function, is followed by loss of activity.

Selective α,α-Dibromination of Arylethanones with Copper(II) Bromide

2019 ◽  
Vol 16 (9) ◽  
pp. 700-704
Author(s):  
Jitander K. Kapoor ◽  
Loveena Arora ◽  
Om Prakash
Keyword(s):  
Ethyl Acetate ◽  
Heterogeneous System ◽  
Side Chain ◽  
Selective Synthesis ◽  
Aromatic Ketones

Various arylethanones including electron-rich aromatic ketones such as o-hydroxyacetophenone and its p-isomer underwent selective side-chain α,α-dibromination using a heterogeneous system consisting of four molar equivalents of copper(II) bromide in chloroform-ethyl acetate under reflux. This study provides the cleanest method for the selective synthesis of several synthetically useful α,α-dibromoketones which are otherwise difficult to prepare.

Sign in / Sign up

Export Citation Format

Share Document