scholarly journals An Efficient and Mild Method for the Synthesis and Hydrazinolysis ofN-Glyoxylamino Acid Esters

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ayman El-Faham ◽  
Zainab Al Marhoon ◽  
Ahmed Abdel-Megeed ◽  
Mohamed Siddiqui
Keyword(s):  
Hydrazine Hydrate ◽  
Good Yield ◽  
Acid Ester ◽  
Ring Opening ◽  
Acid Hydrazide ◽  
Type Reaction ◽  
H Nmr ◽  
Elemental Microanalysis ◽  
Acid Esters ◽  
C Nmr

N-Glyoxylamino acid ester derivatives were synthesized via the ring opening ofN-acetylisatin using moderate conditions. During the hydrazinolysis ofN-glyoxylamino acid ester derivatives with hydrazine hydrate (80%) in methanol, unexpected reduction of theα-keto group occurred to affordN-acylamino acid hydrazide derivatives in good yield (80–90%) (Wolff-Kishner type reaction). All the synthesized compounds were characterized by1H NMR,13C NMR, and elemental microanalysis.

Reaction of Pyrylium Salts with Nucleophiles. Part 24.New Mono- and Bispyridinium Salts with a Central 2,5-Diaryloxazole Group

1997 ◽  
Vol 62 (5) ◽  
pp. 769-780 ◽  
Author(s):  
Iosif Schiketanz ◽  
Daniela Istrati ◽  
Calin Deleanu ◽  
Constantin Draghici ◽  
Alexandru T. Balaban
Keyword(s):  
Hydrazine Hydrate ◽  
Raney Nickel ◽  
Good Yield ◽  
Nmr Spectra ◽  
Amino Group ◽  
Aryl Ring ◽  
H Nmr ◽  
Pyrylium Salts ◽  
C Nmr

Reduction of nitro substituted 2,5-diaryloxazoles with hydrazine hydrate and Raney nickel affords in good yield 2,5-diaryloxazoles having amino group(s) on the aryl ring(s) . The reaction of 2,4,6-trisubstituted pyrylium perchlorates with mono- and diamino-2,5-diaryloxazoles yields new mono- and bispyridinium perchlorates with a central 2,5-diaryloxazole group. Their electronic, 13C NMR and 1H NMR spectra are presented and discussed.

scholarly journals Synthesis of New Imidazolidine and Tetrahydropyrimidine Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Hamid Beyzaei ◽  
Reza Aryan ◽  
Zahra Keshtegar
Keyword(s):  
Ring Opening ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Ir Spectrometry ◽  
H Nmr ◽  
Chemical Structures ◽  
Thioamide Group ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
C Nmr

Synthesis of new imidazolidine and tetrahydropyrimidine derivatives 3a, b and 4a–c as cyclic 1,3-diamines under two reaction conditions (A and B) is described. Under reaction conditions-A, a suspension of (E)-2-cyano-2-(oxazolidin-2-ylidene)ethanethioamide 1 (1 eq.) and diaminoalkanes 2a–e (2 eq.) in absolute ethanol is heated under reflux for 16–22 h to afford 3a, b and 4a–c. Alternatively, under reaction conditions-B, a solution of thioamide 1 (1 eq.) in diaminoalkanes 2a–e (3 eq.) is stirred under solvent-free conditions at room temperature for 3 days to give desired products. Reaction conditions-A for having higher yields, shorter reaction times, and required less diamines is more effective than reaction conditions-B. Oxazolidine ring opening is observed by reacting compound 1 with all of the diamines 2a–e, but the thioamide group only reacts with nonbulky diamines 2a, b. The chemical structures of novel compounds were confirmed by 1H NMR, 13C NMR, elemental analysis, and FT-IR spectrometry.

Synthesis and characterization of polyvinylmethylsiloxanes by cationic polymerization using a solid green catalyst

e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 439-448 ◽  
Author(s):  
Djamal Eddine Kherroub ◽  
Mohammed Belbachir ◽  
Saad Lamouri
Keyword(s):  
Ring Opening ◽  
Polymeric Materials ◽  
Synthesis And Characterization ◽  
Green Catalyst ◽  
Characterization Methods ◽  
H Nmr ◽  
New Strategy ◽  
Cationic Ring Opening Polymerization ◽  
C Nmr

AbstractThe present work is devoted to the synthesis and characterization of vinylsiloxane polymers produced by the use of an activated natural catalyst known as Maghnite-H+. The cationic ring opening polymerization of pentavinylpentamethylcyclopentasiloxane (V5D5) made it possible to obtain the desired polymeric materials. Through this study, we have adapted a new strategy of synthesis of a siloxane polymer with relatively high molecular mass, using a solid initiator activated by sulfuric acid, which has enabled us to combine the ecological aspect of synthesis and the effectiveness of the catalyst in this kind of reaction. Structural [infrared (IR), proton and carbon nuclear magnetic resonance (1H NMR and 13C NMR)], thermal differential scanning (DSC) and chromatographic (GPC) characterization methods have allowed the products obtained to be identified and their various properties to be focused on. The kinetic study was made to determine the order of the reaction. The proposed reaction mechanism shows the advantages of Maghnite-H+.

Synthesis and reactions of indeno[1,2-c]chromene-6,11-dione derivatives

2008 ◽  
Vol 2008 (11) ◽  
pp. 609-612 ◽  
Author(s):  
Mahmoud R. Mahmoud ◽  
Manal M. El-Shahawi ◽  
Eman A.A. El-Bordany ◽  
Fatma S.M. Abu El-Azm
Keyword(s):  
Mass Spectra ◽  
Acid Hydrazide ◽  
Sodium Hydride ◽  
Hydroxylamine Hydrochloride ◽  
Cyanoacetic Acid ◽  
H Nmr ◽  
Concentrated Sulfuric Acid ◽  
Nitrogen Nucleophiles ◽  
Cyanoacetic Acid Hydrazide ◽  
C Nmr

Indeno[1,2-c]chromene-6,11-dione was prepared using the readily obtainable starting materials via the condensation of dimethyl homophthalate with 2,6-dichlorobenzaldehyde in the presence of sodium hydride in dry benzene followed by saponification and cyclisation with concentrated sulfuric acid at 0°C. The tendency of indeno[1,2-c]chromene-6,11-dione for undergoing nucleophilic addition has been tested by reaction with nitrogen nucleophiles such as hydrazine hydrate, hydroxylamine hydrochloride, ethyl carbazate, cyanoacetic acid hydrazide, thiosemicarbazide and 4-methylbenzenesulfonohydrazide. The IR, 1H NMR, 13C NMR and mass spectra of the synthesised compounds are discussed.

A New Green Process for Synthesising High Quality PLLA Materials

2013 ◽  
Vol 750-752 ◽  
pp. 1377-1380 ◽  
Author(s):  
Hui Li Shao ◽  
Xian Jue Zhou ◽  
Xue Chao Hu
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Green Process ◽  
Weight Average Molecular Weight ◽  
H Nmr ◽  
Ft Ir ◽  
C Nmr

Synthesis of Poly(L-lactide) (PLLA) by the ring-opening polymerization (ROP) of L-lactides in supercritical carbon dioxide (SC-CO2) with co-solvent were studied. Effects of kinds of co-solvent on the molecular weight (MW) and the molecular weight distribution (MWD) of the resultant polymers were investigated by the gel permeation chromatography (GPC). The resultant polymers were also characterized with1H NMR,13C NMR and FT-IR. It was found that PLLA with high purity and almost without racemization could be obtained by this technology and the acetone is the best co-solvent for this kind of polymerization. By using stannous octoate as initiator and acetone as co-solvent, PLLA having a weight-average molecular weight (Mw) near to 9×104and polydispersity index (PDI) of 1.7 was successfully synthesized.

scholarly journals The Design, Synthesis, and Characterization of Resveratrol Derivatives Modified by Different γ-Aminobutyric Acid Esters

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Bing Ren Tian ◽  
Jia Yue Liu ◽  
Hu Rong Ge ◽  
Zhi Zhong Wang ◽  
Shao Yun Huang ◽  
...  
Keyword(s):  
Water Solubility ◽  
Molecular Transport ◽  
Aminobutyric Acid ◽  
Molecular Water ◽  
Polar Surface Area ◽  
Design Synthesis ◽  
H Nmr ◽  
Acid Esters ◽  
C Nmr

A novel series of resveratrol modified by γ-aminobutyric acid esters were designed and synthesized. Then, the products were characterized by 1H-NMR, 13C-NMR, and MS, and the melting point was determined. Molecular water solubility, polar surface area, and octanol-water partition were calculated, which correlated well with molecular transport through membranes and, therefore, enabled prediction of transport properties of drugs.

scholarly journals Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

2013 ◽  
Vol 9 ◽  
pp. 767-774 ◽  
Author(s):  
Hao Zhong ◽  
Jianwu Shi ◽  
Jianxun Kang ◽  
Shaomin Wang ◽  
Xinming Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ring Opening ◽  
H Nmr ◽  
Ring Opening Reaction ◽  
Ring Opening Reactions ◽  
C Nmr

In this paper, the ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene with aryllithium in THF at low temperature to generate 2'-arylthio-3,3'-bithiophene-2-carbaldehydes is studied. Nine examples are explored and all the products are characterized by 1H NMR, 13C NMR and HRMS. The relative relationship between the structures of aryl groups and the efficiency of ring-opening reactions are discussed.

Penicilloitins A and B, new antimicrobial fatty acid esters from a marine endophytic Penicillium species

2016 ◽  
Vol 71 (11-12) ◽  
pp. 387-392 ◽  
Author(s):  
Samar S.A. Mourshid ◽  
Jihan M. Badr ◽  
April L. Risinger ◽  
Susan L. Mooberry ◽  
Diaa T.A. Youssef
Keyword(s):  
Fatty Acid ◽  
Cyclopiazonic Acid ◽  
2D Nmr ◽  
Culture Broth ◽  
Fatty Acid Esters ◽  
Spectroscopic Techniques ◽  
Penicillium Species ◽  
H Nmr ◽  
Acid Esters ◽  
C Nmr

Abstract Two new antimicrobial fatty acid esters, penicilloitins A and B (1 and 2), along with α-cyclopiazonic acid (3), tryptamine (4) and indole-3-carbaldehyde (5), were isolated from mycelial extracts and the culture broth of a marine endophytic Penicillium species and their structures established by spectroscopic techniques including 1D (1H NMR and 13C NMR) and 2D NMR (COSY, multiplicity-edited HSQC, and HMBC) as well as HRESIMS. Of these compounds, 1, 3 and 4 displayed modest antimicrobial activity.

scholarly journals Microwave Assisted Synthesis of New 1-{2, 4-Dihydroxy-5-[5-(aryl)-1-pyridine/pyrimidine-4-carbonyl)-4, 5-dihydro-1H-pyrazol-3-yl]-phenyl}-3-(aryl)-propenones and their Antibacterial Activity

2009 ◽  
Vol 6 (2) ◽  
pp. 323-331
Author(s):  
D. Ashok ◽  
K. Aravind
Keyword(s):  
Antibacterial Activity ◽  
Microwave Irradiation ◽  
Spectral Data ◽  
Acid Hydrazide ◽  
Microwave Assisted Synthesis ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
H Nmr ◽  
Microwave Assisted ◽  
C Nmr

A series of 1-{2, 4-dihydroxy-5-[5-(aryl)-1-pyridine/pyrimidine-4-carbonyl)-4, 5-dihydro-1H-pyrazol-3-yl]-phenyl}-3-(aryl)-propenones (2a-h) have been synthesized from 1-[2,4-dihydroxy-5-(aryl acryloyl)phenyl]-aryl propenones(1a-h)by Micheal addition with isoniazide/pyrazinic acid hydrazide under microwave irradiation and classical heating. The synthesized compounds were characterized by IR,1H-NMR,13C-NMR and Mass spectral data. All the compounds were screened for their Antibacterial activity.

scholarly journals Synthesis and characterization of some novel 1,2,4-triazoles, 1,3,4-thiadiazoles and Schiff bases incorporating imidazole moiety as potential antimicrobial agents

2015 ◽  
Vol 65 (2) ◽  
pp. 117-132 ◽  
Author(s):  
Mohamed Reda Aouad ◽  
Mouslim Messali ◽  
Nadjet Rezki ◽  
Adeeb Al-Sheikh Ali ◽  
Alain Lesimple
Keyword(s):  
Hydrazine Hydrate ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Potassium Hydroxide Solution ◽  
Acid Hydrazide ◽  
Aromatic Aldehydes ◽  
Mass Spectral ◽  
H Nmr ◽  
Acidic Conditions

Abstract (1,4,5-Triphenylimidazol-2-yl-thio)butyric acid hydrazide (3) was obtained via alkylation of 1,4,5-triphenylimidazol-2- thiol (1) with ethylbromobutyrate, followed by addition of hydrazine hydrate. Treatment of acid hydrazide 3 with carbon disulfide in an ethanolic potassium hydroxide solution gave the intermediate potassium dithiocarbazinate salt, which was cyclized to 4-amino-5-[(1,4,5-triphenylimidazol- -2-yl)thiopropyl]-2H-1,2,4-triazole-3-thione (4) in the presence of hydrazine hydrate. Condensation of compound 3 with alkyl/arylisothiocyanate afforded the corresponding 1-[4-(1,4,5-triphenylimidazol-2-ylthio)butanoyl]-4-alkyl/arylthiosemicarbazides (5-7), which upon refluxing with sodium hydroxide, yielded the corresponding 1,2,4-triazole - -3-thiols 8-10. Under acidic conditions, compounds 4-6 were converted to aminothiadiazoles 11-13. Moreover, the series of Schiff bases 14-18 were synthesized from the condensation of compound 3 with different aromatic aldehydes. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral analyses. They were also preliminarily screened for their antimicrobial activity.

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