Studies on Ylides: Reactions of N -Pyridinium Phenancylides with α,β-Unsaturated Ketones, I

1974 ◽  
Vol 29 (7-8) ◽  
pp. 552-555 ◽  
Author(s):  
Purshottam S. Kendurkar ◽  
Ram S. Tewari
Keyword(s):  
Acetic Acid ◽  
Nmr Spectra ◽  
Ammonium Acetate ◽  
Ir And Nmr Spectra ◽  
Unsaturated Ketones

Reactions of N-pyridinium phenancylides with different a, β-unsaturated ketones give 2,4,6-triarylsubstituted pyridines, 2,6-diphenyl-4-(2-pyridyl) pyridines, 2-benzylidene-4,6-diphenyl pyridines and 2,4,6-triphenyl-3-bromopyridine. Ammonium acetate in acetic acid was used as cyclization agent. The structure of the products are supported by IR and NMR spectra.

Reactivity of Some 1(N)‐[(para‐R2)‐Phenacyl]–4(N)‐[(para‐R1)‐phenyl]‐1,2,4‐triazolium‐methylides by UV‐VIS, IR, and NMR Spectra and Molecular Modeling

2004 ◽  
Vol 37 (5) ◽  
pp. 457-467 ◽  
Author(s):  
Nicoleta Melniciuc‐Puică ◽  
Virgil Bărboiu ◽  
Şerban Filoti ◽  
Dana‐Ortansa Dorohoi
Keyword(s):  
Molecular Modeling ◽  
Nmr Spectra ◽  
Ir And Nmr Spectra

Dppa als Komplexligand: Metall-Koordination und P-N-Spaltung in Komplexen des Typs [CpM(L)dppa]X (M = Fe, Mn; L = CO, NO) / Dppa as a Ligand: Metal Coordination and P-N Cleavage in Complexes of the Type [CpM(L)dppa]X (M = Fe, Mn; L = CO, NO)

1997 ◽  
Vol 52 (5) ◽  
pp. 593-603 ◽  
Author(s):  
Jan Geicke ◽  
Ingo-Peter Lorenz ◽  
Petra Mürschel ◽  
Kurt Polbom
Keyword(s):  
Nmr Spectra ◽  
Metal Coordination ◽  
Cleavage Reaction ◽  
Neutral Complex ◽  
Ir And Nmr Spectra ◽  
X Ray

Abstract The reactions of [CpMn(CO)2(NO)]BF4 or CpFe(CO)2Cl with PPh2NHR (R = Ph, PPh2) lead to the salts [CpML(CO)PPh2NHR]X with monodentate aminophosphine ligands. In the case of R = PPh2 (= dppa) the complexes [CpML(dppa)]X with bidentate dppa are also formed. The salt [CpFe(CO)(dppa)]Cl can be deprotonated to give the neutral complex CpFe(CO){(PPh2)2N)} with the diphosphinoamide ligand, which can be N-alkylated by Mel to afford [CpFe(CO){(PPh2)2NMe}]I. The complex [CpMn(NO)(dppa)]BF4 undergoes a P-N cleavage reaction by the solvent methanol to form [CpMn(NO)(PPh2NH2)(PPh2OMe)]BF4. The non-chelated complexes [CpFe(CO)2PPh2NHR]Cl are deprotonated by DBU to give the neutral ferrioiminophosphoranes CpFe(CO)2PPh2 = NR. For R = PPh2 photolysis leads to CO-elimination and to CpFe(CO)(PPh2NPPh2). CpFe(CO)2PPh2NPPh2 can be alkylated by Mel or metallated by CpFe(CO)2Cl to form [CpFe(CO)2PPh2NPPh2Me]I or [CpFe(CO)2PPh2NPPh2(CO)2FeCp]Cl, respectively. Oxidation of CpFe(CO)2PPh2NPPh2 is possible by (SiMe3)2O2, sulfur, or selenium to lead to the neutral complexes CpFe(CO)2PPh2=NPPh2 = E (E = O, S, Se) with a heterodiene system. The IR and NMR spectra of all species as well as the X-ray structures of the complexes [CpFe(CO)dppa]Cl, [CpMn(NO)dppa]BF4 and [CpMn(NO)(PPh2NH2)(PPh2OMe)]BF4 are reported and discussed.

MECHANICAL PULPING: Characterization of dissolving pulp by multivariate data analysis of FT-IR and NMR spectra

2011 ◽  
Vol 26 (4) ◽  
pp. 398-409 ◽  
Author(s):  
Peter Strunk ◽  
Tommy Ö Öman ◽  
Mattias Hedenström ◽  
Bertil Eliasson ◽  
András Gorzsás
Keyword(s):  
Data Analysis ◽  
Multivariate Data Analysis ◽  
Nmr Spectra ◽  
Multivariate Data ◽  
Dissolving Pulp ◽  
Ir And Nmr Spectra ◽  
Ft Ir

Determination and Identification of Chondroitin Sulfate from Tilapia Byproducts

2013 ◽  
Vol 690-693 ◽  
pp. 1318-1321 ◽  
Author(s):  
Zhen Hua Duan ◽  
Chang Yu Cheng ◽  
Yang Hai ◽  
Ju Lan Wang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Magnetic Resonance ◽  
Chondroitin Sulfate ◽  
Infrared Spectra ◽  
Oreochromis Niloticus ◽  
High Performance ◽  
Nmr Spectra ◽  
Ir And Nmr Spectra

In order to probe the structure of chondroitin sulfate (CS) from tilapia fish, the CS was extracted from tilapia (Oreochromis niloticus) byproducts with the combination of ultrasonic and microwave, some means including high performance liquid chromatography (HPLC), infrared spectra (IR) and nuclear magnetic resonance (NMR) were used in this paper. The data of HPLC exhibited that the obtained chondroitin sulfate is of highly purity (98.78%). IR and NMR spectra indicated that the sample consisted of both chondroitin-4-sulfate and chondroitin-6-sulfate, and the proportion of chondroitin-6-sulfate was higher than chondroitin-4-sulfate.

Hydrolysis of Zirconium Propoxide by an Esterification Reaction

1992 ◽  
Vol 271 ◽  
Author(s):  
I. Laaziz ◽  
A. Larbot ◽  
C. Guizard ◽  
A. Julbe ◽  
L. Cot
Keyword(s):  
Acetic Acid ◽  
Light Scattering ◽  
Crystalline Structure ◽  
Structure Determination ◽  
Nmr Spectra ◽  
Esterification Reaction ◽  
Zirconium Propoxide ◽  
Size Growth ◽  
Hydrolysis Of

ABSTRACTZirconium propoxide hydrolysis was performed with the help of an esterification reaction using acetic acid. Products, obtained according to the value of hydrolysis ratio, are successively crystals, sols and gels or precipitates. The similarity of FUR and NMR spectra for crystals and gels allows to think that the arrangements of ligands around the zirconium atoms are close. The crystalline structure determination permits to precise the environment : acetate groups are always bridging and propoxy groups can be bridging or terminal. Clusters containing 9 zirconium atoms, bridged by oxygen atoms, exist in the structure. The colloid size growth was performed by light scattering. A discussion of the role of acetic acid and the competition between the possible reactions is given.

Enaminones as Building Blocks In Heterocyclic Synthesis: A New One Pot Synthesis of Polyfunctional Substituted Pyridines

2001 ◽  
Vol 56 (10) ◽  
pp. 1074-1078 ◽  
Author(s):  
Samia Michel Agamy ◽  
Mervat Mohammed Abdel-Khalik ◽  
Mona Hassan Mohamed ◽  
Mohammed Hilmy Elnagdi
Keyword(s):  
Acetic Acid ◽  
Double Bond ◽  
Aromatic Aldehyde ◽  
Michael Addition ◽  
Ammonium Acetate ◽  
Building Blocks ◽  
Heterocyclic Synthesis ◽  
One Pot ◽  
Active Methyl ◽  
Substituted Pyridines

Enaminones react with a variety of active methyl and methylene reagents in presence of ammonium acetate to yield functionally substituted pyridines in good yields. The reaction proceeded via initial Michael addition across the double bond followed by cyclization. The reaction of enaminone with aromatic aldehyde in acetic acid/ammonium acetate afforded the dihydropyridine that was oxidized to the corresponding pyridine.

scholarly journals New Synthetic Routes for 1-Benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-Tetraazacyclododecane-1-acetic Acid Ethyl Ester, Important Starting Materials for Metal-coded DOTA-Based Affinity Tags

2007 ◽  
Vol 62 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Stephan W. Kohl ◽  
Katharina Kuse ◽  
Markus Hummert ◽  
Herbert Schumann ◽  
Clemens Mügge ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Ester ◽  
Nmr Spectra ◽  
Acid Ethyl Ester ◽  
Affinity Tags ◽  
X Ray ◽  
H Nmr ◽  
Synthetic Routes ◽  
New Compounds ◽  
C Nmr

Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10- tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane- 4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl)diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.

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