Cyanoethylation and (Methoxycarbonyl)ethylation of Icosahedral ortho-Carborane Derivatives at Carbon Vertices via Michael Additions

2001 ◽  
Vol 66 (10) ◽  
pp. 1499-1507 ◽  
Author(s):  
Jaromír Plešek ◽  
Jaroslav Bačkovský ◽  
Jiří Fusek ◽  
Zbyněk Plzák
Keyword(s):  
Mass Spectrometry ◽  
Methyl Acrylate ◽  
Michael Addition ◽  
Nmr Spectra ◽  
Ammonium Hydroxide ◽  
Phase System ◽  
Melting Points ◽  
Two Phase ◽  
Michael Additions

The C-H vertices of ortho-carborane and its derivatives can be smoothly cyanoethylated with acrylonitrile in the presence of benzyl(triethyl)ammonium hydroxide in a two-phase system: dichloromethane/water or 1,2-dimethoxyethane/water. The reaction is highly specific and not transferable to its meta and para isomers. No Michael addition with methyl acrylate takes place under these conditions. However, with NaH as catalyst (methoxycarbonyl)ethylation can be accomplished with ortho-carborane; meta and para isomers react neither with acrylonitrile, nor with methyl acrylate even under such forcing conditions. The syntheses, properties and constitutions of 1-(2-cyanoethyl)-ortho-carborane, 1-(2-cyanoethyl)-2-phenyl-ortho-carborane, 1,2-bis(2-cyanoethyl)-ortho-carborane, 1-[2-(methoxycarbonyl)ethyl]-ortho-carborane and 1,2-bis[2-(methoxycarbonyl)ethyl]-ortho-carborane, along with their respective acids, are described. Melting points, TLC, "heated-inlet" mass spectrometry, and the 1H and 11B NMR spectra of all compounds, are presented. The scope of cyanoethylations and (methoxycarbonyl)ethylations of other deltahedral carbaboranes and heteroboranes is considered.

Gas Column/Mass Spectrometry Analysis of Bio Oil Treated by Aqueous Two Phase System

2011 ◽  
Vol 236-238 ◽  
pp. 54-58
Author(s):  
Shao Peng Liu ◽  
Zhi Min Zong ◽  
Shan Shan Zhang ◽  
Yue Xu ◽  
Gui Zhen Gong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometry Analysis ◽  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Spectrometry Analysis ◽  
Bio Oil ◽  
Aqueous Two Phase Systems ◽  
Phase Systems ◽  
Ethanol System

Bio oil aqueous two phase systems were formed with ethanol and the salts of (NH4)2SO4, K2HPO4 and NaH2PO4 in bio oil on the ratio of 10:5:10(by mass). After phase separation, both the upper and the lower layers were analyzed by gas column/mass spectrometry (GC/MS). As a result, both K2HPO4/ethanol and NaH2PO4/ethanol system can enrich phenols and levoglucosan in the upperand lower layers,respectly, while NaH2PO4/ethanol system seldom changes the components of bio oil; the (NH4)2SO4/ethanol system is quit different with the other two and we have detected some components with nitrogen. Hence, NaH2PO4/ethanol is an advantage aqueous two phase system for bio oil treatment.

Studies on Thermomechanical Characteristics of Poly(Methyl Methacrylate) and Ethylene-Methyl Acrylate Copolymer Blends

2012 ◽  
Vol 20 (8) ◽  
pp. 749-754
Author(s):  
P. Poomalai ◽  
T.O. Varghese ◽  
Siddaramaiah
Keyword(s):  
Methyl Methacrylate ◽  
Methyl Acrylate ◽  
Mechanical Analysis ◽  
Phase System ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Two Phase ◽  
Poly Methyl Methacrylate ◽  
Acrylate Copolymer ◽  
Ethylene Methyl Acrylate

Blends of poly(methyl methacrylate) (PMMA) with ethylene - methyl acrylate (EMA) copolymers of different compositions, viz. 95/05, 90/10, 85/15 and 80/20 wt.% were prepared by a melt mixing technique using a twin-screw extruder. The blends were characterized by thermo-analytical methods, viz. differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The TGA of PMMA/EMA blends show that thermal degradation takes place in two steps and the temperature of the decomposition rate maximum is proportional to the compositions of the blends. The DSC studies reveal two glass-transition temperatures (Tg) for all the blends corresponding to their individual components which indicates that the blends are incompatible. The DMA thermograms exhibit two steps in the dynamic modulus-temperature curves for higher EMA content, which is characteristic of immiscible polymers in a two phase system.

Efficient synthetic access to novel indolo[2,3-b]quinoxaline-based heterocycles

2021 ◽  
Vol 18 ◽  
Author(s):  
Ahmed Abdou O. Abeed ◽  
Talaat I. El-Emary ◽  
Sarah Alharthi
Keyword(s):  
Organic Chemistry ◽  
Mass Spectrometry ◽  
Heterocyclic Compounds ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Melting Points ◽  
Internal Reference ◽  
Elemental Analyses ◽  
Ft Ir ◽  
Synthetic Routes

Background: This paper showed the synthetic capability of the indolo[2,3-b]quinoxaline nucleus to be provided as an excellent precursor for the synthesis of various heterocyclic compounds. These synthetic routes proceed via the formation of 3-(6H-indolo[2,3-b]quinoxalin-6-yl)propane hydrazide (2). The carbohydrazide 2 and its reactions with different reagents give five and six-membered rings, such as 1,3,4-thiadiazole, 1,3,4-oxadiazole, 1,2,4-triazole, and 1,2,4-triazine. Methods: All chemicals used in the current study were of analytical grade. Melting points were determined using an APP Digital ST 15 melting point apparatus and were uncorrected. FT-IR spectra were recorded on a Pye-Unicam SP3-100 and Shimadzu-408 spectrophotometers in KBr pellets and given in (cm-1) KBr. The NMR spectra were detected by a Bruker AV-400 spectrometer (400 MHz for 1H, 100 MHz for 13C and 40.55 MHz for 15N), Institute of Organic Chemistry, Karlsruhe, Germany. Chemical shifts were expressed as δ (ppm) with TMS as an internal reference. Mass spectrometry was provided on a Varian MAT 312 instrument in EI mode (70 eV). Results: The target compounds were obtained, and their structures were completely elucidated by various spectral and elemental analyses (Ft-IR, 1H-NMR, 13C-NMR, and mass spectrometry). Conclusion: The current work showed a view of the reactivity of the carbohydrazide group. The carbohydrazide 2 was obtained from the hydrazinolysis of carboethoxy compound 1 and exploited as a key intermediate to synthesize heterocyclic compounds with different rings.

On the Problem of “Two-Phase” Activated Sludge

1991 ◽  
Vol 24 (7) ◽  
pp. 59-64 ◽  
Author(s):  
R. W. Szetela
Keyword(s):  
Activated Sludge ◽  
Single Phase ◽  
Phase System ◽  
Two Phase ◽  
Wastewater Treatment Process ◽  
Sludge Stabilization ◽  
Technological Advantage ◽  
In Series ◽  
State Models ◽  
Activated Sludge Systems

Steady-state models are presented to describe the wastewater treatment process in two activated sludge systems. One of these makes use of a single complete-mix reactor; the other one involves two complete-mix reactors arranged in series. The in-series system is equivalent to what is known as the “two-phase” activated sludge, a concept which is now being launched throughout Poland in conjunction with the PROMLECZ technology under implementation. Analysis of the mathematical models has revealed the following: (1) treatment efficiency, excess sludge production, energy consumption, and the degree of sludge stabilization are identical in the two systems; (2) there exists a technological equivalence of “two-phase” sludge with “single-phase” sludge; (3) the “two-phase” system has no technological advantage over the “single-phase” system.

Enantioselective Michael Addition of Malonates to Enones

2020 ◽  
Vol 24 (7) ◽  
pp. 746-773
Author(s):  
Péter Bakó ◽  
Tamás Nemcsok ◽  
Zsolt Rapi ◽  
György Keglevich
Keyword(s):  
Michael Addition ◽  
Activity Relationship ◽  
Chalcone Derivatives ◽  
Michael Additions ◽  
Michael Reactions ◽  
Structure Activity ◽  
Cyclic Enones ◽  
Michael Acceptors ◽  
Relationship Of ◽  
Enantioselective Catalysts

: Many catalysts were tested in asymmetric Michael additions in order to synthesize enantioenriched products. One of the most common reaction types among the Michael reactions is the conjugated addition of malonates to enones making it possible to investigate the structure–activity relationship of the catalysts. The most commonly used Michael acceptors are chalcone, substituted chalcones, chalcone derivatives, cyclic enones, while typical donors may be dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, di-tert-butyl and dibenzyl malonates. This review summarizes the most important enantioselective catalysts applied in these types of reactions.

Interphase distribution of 2-furylethylenes

1985 ◽  
Vol 50 (8) ◽  
pp. 1642-1647 ◽  
Author(s):  
Štefan Baláž ◽  
Anton Kuchár ◽  
Ernest Šturdík ◽  
Michal Rosenberg ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Transport Rate ◽  
Phase System ◽  
Two Phase ◽  
Interphase Distribution ◽  
Distribution Kinetics ◽  
System 1 ◽  
Kinetics Of

The distribution kinetics of 35 2-furylethylene derivatives in two-phase system 1-octanol-water was investigated. The transport rate parameters in direction water-1-octanol (l1) and backwards (l2) are partition coefficient P = l1/l2 dependent according to equations l1 = logP - log(βP + 1) + const., l2 = -log(βP + 1) + const., const. = -5.600, β = 0.261. Importance of this finding for assesment of distribution of compounds under investigation in biosystems and also the suitability of the presented method for determination of partition coefficients are discussed.

Enhancing the Sensitivity of DNA and Aptamer Probes in the Dextran/PEG Aqueous Two-Phase System

2021 ◽  
Author(s):  
Qiaoshu Chen ◽  
Yanwen Zhang ◽  
Hui Chen ◽  
Jianbo Liu ◽  
Juewen Liu
Keyword(s):  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System
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