scholarly journals Telomerization of 3,3,3-Trifluoroprop-1-ene and Functionalization of Its Telomers

2008 ◽  
Vol 73 (12) ◽  
pp. 1747-1763 ◽  
Author(s):  
George K. Kostov ◽  
Bruno Améduri ◽  
Stephan Brandstadter
Keyword(s):  
Nmr Spectroscopy ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
Allyl Acetate ◽  
Initial Molar Ratio ◽  
The Third ◽  
Single Isomer ◽  
Butyl Peroxide ◽  
Selective Formation ◽  
C Nmr

The synthesis of four 3,3,3-trifluoroprop-1-ene telomers (RF(C3H3F3)nI, n = 1, 2, RF = n-C6F13- or (CF3)2CF-) and their allyl derivatives RF(C3H3F3)nCH2CH=CH2 are presented. The allyl telomers were prepared by a three-step reaction. The first step involved the thermal and peroxide-induced bulk telomerization of 3,3,3-trifluoroprop-1-ene (TFP) with heptafluoro-2-iodopropane or tridecafluoro-6-iodohexane leading to monoadduct and diadduct, the ratio of which depends on the R0 = [RFI]0/[TFP]0 initial molar ratio and the reaction temperature. The amount of monoadduct increased up to 50-60% and of the diadduct to 25-30% at temperatures up to 180 °C (thermal-initiated) and 150 °C (initiated with di-tert-butyl peroxide, DTBP), R0 up to 1.5. It was observed that the addition of the (CF3)2CF• radical onto the =CH2 of TFP was regioselective leading to selective formation of a single isomer in contrast to the addition of the n-C6F13• radical. Then, the telomers reacted with allyl acetate yielding RF(C3H3F3)nCH2CH(I)CH2OCOCH3 (n = 1, 2) in 50-80% yields. The third step consisted of a deiododeacetatization of these iodoacetates into RF(C3H3F3)nCH2-CH=CH2 (C,n) giving 50-80% yields. All the intermediates were characterized by 1H, 19F and products by 13C NMR spectroscopy.

A Simple and Efficient Route for Preparing 4-Chloro-3,5-Dinitropyrazole

2014 ◽  
Vol 1025-1026 ◽  
pp. 466-469
Author(s):  
Qiao Rui ◽  
Yan Hong Wang ◽  
Yong Xiang Li
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
H Nmr ◽  
Energetic Compound ◽  
Efficient Route ◽  
Optimum Reaction ◽  
Single Factor Experiment ◽  
Optimum Reaction Condition ◽  
C Nmr

4-Chloro-3,5-dinitropyrazole(ClDNP) as an insensitive energetic compound has been prepared with 4-Chloropyrazole(4-ClP)via nitrated by mixture of nitric acid and sulfuric acid. The reactionconditions were investigated, such as the molar ratio of 4-chloropyrazole and HNO3, reaction temperature, reaction time. Through the single factor experiment, the optimum reaction condition was determined that the molar ratio of 4-chloropyrazole and HNO3 was 1:4, the reaction time was 4h, the reaction temperature was 100-105°C. The yield of the ClDNP was up to 73.8% under the above conditions．The ClDNP was re-crystallization by methylbenzene.The target product was characterized by IR, 1H NMR, 13C NMR and Gauss Photography．

The mechanism of formation of 2,7-dimethyl-2,6-octadiene in the synthesis of 3-methylene-7-methyl-1,6-octadiene

1983 ◽  
Vol 48 (7) ◽  
pp. 1864-1866
Author(s):  
Jan Bartoň ◽  
Ivan Kmínek
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Alkali Metal ◽  
Chromatographic Analysis ◽  
Solid Phase ◽  
Reaction Pathway ◽  
Mechanism Of Formation ◽  
Gas Chromatographic Analysis ◽  
C Nmr ◽  
Visual Observations

2,7-Dimethyl-2,6-octadiene is formed in the catalytic solution for the dimerization of 2-methyl-1,3-butadiene to β-myrcene (3-methylene-7-methyl-1,6-octadiene), as revealed by mass spectrometry and 13C NMR spectroscopy. Visual observations together with the results of gas chromatographic analysis of the catalytic solution suggest that the formation of 2,7-dimethyl-2,6-octadiene is associated with the transition of the alkali metal (sodium) from the solid phase into the solution. A reaction pathway is suggested accounting for the formation of 2,7-dimethyl-2,6-octadiene in the system.

Non-cyclol (lactame) ergot alkaloids

1982 ◽  
Vol 47 (12) ◽  
pp. 3312-3317 ◽  
Author(s):  
Josef Stuchlík ◽  
Alois Krajíček ◽  
Ladislav Cvak ◽  
Jiří Spáčil ◽  
Petr Sedmera ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ergot Alkaloids ◽  
C Nmr

Two new alkaloids were isolated from the field ergot. Their structures, N-(D-lysergyl-L-valyl)cyclo(L-valyl-D-prolyl) (IV) and N-(D-lysergyl-L-valyl)cyclo(L-leucyl-D-prolyl) (V), were assigned by mass, 1H and 13C NMR spectroscopy.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

A New Dimeric Derivative of Ethoxyquin from Its Reaction with Alkylperoxy Radicals

1993 ◽  
Vol 58 (8) ◽  
pp. 1914-1918 ◽  
Author(s):  
Jaroslav Kříž ◽  
Luděk Taimr
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Peroxy Radicals ◽  
Methyl Group ◽  
Alkylperoxy Radicals ◽  
C Nmr

The structure of a new compound formed in the reaction of ethoxyquin with alkylperoxy radicals was resolved by 1H and 13C NMR spectroscopy (including COSY, NOESY, HHC RCT and SSLR INEPT techniques) and confirmed by mass spectrometry. The structure suggest participation of 4-methyl group of ethoxyquin in the deactivation of peroxy radicals. A mechanism of this reaction is proposed.

Reactivity of Sodium Hexaethyl-2,4-dicarba-nido-hexaborate(1-)

1999 ◽  
Vol 64 (6) ◽  
pp. 977-985 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz ◽  
Wolfgang Milius ◽  
Catherine McCammon
Keyword(s):  
Mössbauer Spectroscopy ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Hydrogen Atom ◽  
Mossbauer Spectroscopy ◽  
Sandwich Complex ◽  
X Ray ◽  
Bromo Derivative ◽  
Boron Tribromide ◽  
C Nmr

Sodium hexaethyl-2,4-dicarba-nido-hexaborate(1-) (6), available from hexaethyl-2,4-dicarba- nido-hexaborane(8) (4) by deprotonation, reacts with deuterated methanol, CD3OD, to give back 4 without H/D exchange of the B-H-B hydrogen atom. The reaction of 6 with diethylboron chloride, Et2BCl, affords hexaethyl-2,4-dicarba-closo-hexaborane(6) (7), the first example of a peralkylated carborane of this type. In contrast, the reaction of 6 with boron tribromide, BBr3, leads mainly to 2,3,4,5,6,7-hexaethyl-2,4-dicarba-closo-heptaborane(7) (8), together with the corresponding 1-bromo derivative (9) and the closo-carborane 7 as side products. The reaction of two equivalents of 6 with FeCl2 gives the air-stable sandwich complex bis[hexaethyl-2,4-dicarba-nido-hexaborate(1-)]iron 10 which was characterised by X-ray structural analysis. All products were characterised by 1H, 11B and 13C NMR spectroscopy, and 57Fe Mössbauer spectroscopy was used to study 10.

Formation of spiro adduct from N-methyl-N-(2,4,6-trinitrophenyl)glycine anion

1989 ◽  
Vol 54 (2) ◽  
pp. 440-445 ◽  
Author(s):  
Vladimír Macháček ◽  
Alexandr Čegan ◽  
Miloš Sedlák ◽  
Vojeslav Štěrba
Keyword(s):  
Nmr Spectroscopy ◽  
Dimethyl Sulfoxide ◽  
Equilibrium Constant ◽  
Mole Fraction ◽  
Nucleophilic Addition ◽  
Adduct Formation ◽  
First Case ◽  
C Nmr

The intramolecular nucleophilic addition of N-methyl-N-(2,4,6-trinitrophenyl)glycine anion in methanol-dimethyl sulfoxide mixtures produces spiro[(3-methyl-5-oxazolidinone)-2,1'-(2',4',6'-trinitrobenzenide)]. The spiro adduct has been identified by means of 1H and 13C NMR spectroscopy. This is the first case when the formation of a Meisenheimer adduct with carboxylate ion is observed. Logarithm of the equilibrium constant of adduct formation increases linearly with the mole fraction of dimethyl sulfoxide in its mixture with methanol.

Alterations in Molecular Composition of Humic Substances from Eucalypt Plantation Soils Assessed by 13 C-NMR Spectroscopy

2012 ◽  
Vol 77 (1) ◽  
pp. 293-306 ◽  
Author(s):  
Emanuelle Mercês Barros Soares ◽  
Ivo Ribeiro Silva ◽  
Roberto Ferreira de Novais ◽  
Yan-Yan Hu ◽  
Klaus Schmidt-Rohr
Keyword(s):  
Nmr Spectroscopy ◽  
Humic Substances ◽  
Molecular Composition ◽  
Eucalypt Plantation ◽  
C Nmr

scholarly journals Biogas Dry Reforming for Hydrogen through Membrane Reactor Utilizing Negative Pressure

Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 194-209
Author(s):  
Akira Nishimura ◽  
Tomohiro Takada ◽  
Satoshi Ohata ◽  
Mohan Lal Kolhe
Keyword(s):  
Energy Source ◽  
Reaction Temperature ◽  
Negative Pressure ◽  
Membrane Reactor ◽  
Reaction Chamber ◽  
Dry Reforming ◽  
Molar Ratio ◽  
Effect Of Pressure ◽  
The Impact

Biogas, consisting of CH4 and CO2, is a promising energy source and can be converted into H2 by a dry reforming reaction. In this study, a membrane reactor is adopted to promote the performance of biogas dry reforming. The aim of this study is to investigate the effect of pressure of sweep gas on a biogas dry reforming to get H2. The effect of molar ratio of supplied CH4:CO2 and reaction temperature is also investigated. It is observed that the impact of psweep on concentrations of CH4 and CO2 is small irrespective of reaction temperature. The concentrations of H2 and CO increase with an increase in reaction temperature t. The concentration of H2, at the outlet of the reaction chamber, reduces with a decrease in psweep. It is due to an increase in H2 extraction from the reaction chamber to the sweep chamber. The highest concentration of H2 is obtained in the case of the molar ratio of CH4:CO2 = 1:1. The concentration of CO is the highest in the case of the molar ratio of CH4:CO2 = 1.5:1. The highest sweep effect is obtained at reaction temperature of 500 °C and psweep of 0.045 MPa.

The Chlorination of Di-tert-butyl-2-naphthol+

1984 ◽  
Vol 39 (10) ◽  
pp. 1427-1432
Author(s):  
Edgar Streich ◽  
Anton Rieker
Keyword(s):  
Nmr Spectroscopy ◽  
Tert Butyl ◽  
Chlorine Substitution ◽  
C Nmr

Chlorination of the di-tert-butylation product of 2-naphthol leads to 3,6-di-tert-butyl-1,1-dichloro- l,2-dihydronaphthalen-2-one (4a) instead of 1,6-di-tert-butyl-1,3-dichloro-1,2-dihydronaphthalen-2-one (2) as reported [2], The structural proof was mainly offered by 13C NMR spectroscopy. The influence of annelation and chlorine substitution in 1,2-dihydronaphthalen-2-ones on δ13c=o is discussed, which is of importance for the use of δ13c=o for a general discrimination between ortho- and para-quinolide structures.

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