Synthèse et réactivité des halogéno-2 sulfonyl-2 aziridines

1979 ◽  
Vol 57 (15) ◽  
pp. 1958-1966 ◽  
Author(s):  
Jean-Marc Gaillot ◽  
Yvonne Gelas-Mialhe ◽  
Roger Vessiere
Keyword(s):  
Acidic Medium ◽  
Sodium Methoxide ◽  
Sodium Ethoxide ◽  
Potassium Cyanide

Carbon tetrahalide reacts rapidly with 2-phenylsulfonyl aziridines in the presence of KOH, leading to 2-phenylsulfonyl 2-haloaziridines.Starting with 2-isopropylsulfonyl aziridines, a monochloro and a dichloroaziridine are produced; the Ramberg–Bäcklund reaction is not observed.These halo compounds decompose either thermally or in acidic medium leading to N-substituted α-haloacetamides and α-phenylsulfonylacetamides. 2-Phenylsulfonyl 2-haloaziridines are unreactive toward potassium cyanide or sodium thiophenoxide. Sodium methoxide, sodium ethoxide, or sodium thioethoxide reduce them to 2-phenylsulfonyl aziridines; the reaction depends upon the solvent.

Phosphonium salts. III. The action of cyanide ion and other nucleophiles on some bis-phosphonium salts

1969 ◽  
Vol 22 (7) ◽  
pp. 1405 ◽  
Author(s):  
JJ Brophy ◽  
MJ Gallagher
Keyword(s):  
Sodium Azide ◽  
Sodium Methoxide ◽  
Sodium Acetate ◽  
Potassium Cyanide ◽  
Dimethyl Sulphoxide ◽  
High Yield ◽  
Phosphonium Salts ◽  
Elimination Reaction ◽  
Cyanide Ion ◽  
Reaction Proceeds

Cyclic and acyclic bis-phosphonium salts with a two-carbon bridge are smoothly cleaved to phosphines in high yield by potassium cyanide in dimethyl sulphoxide. Evidence is presented that the reaction proceeds by an elimination-addition sequence. An elimination reaction also occurs when sodium methoxide, sodium azide, sodium acetate, and triethylamine react with ethane-1,2-bis(tri-phenylphosphonium) dibromide. ��� In a novel reaction, triphenylphosphine is converted into its oxide by a mixture of sodium azide and dimethyl sulphoxide.

The effects of various deacetylation procedures on the nylon bag digestibility of barley straw and of grass cell walls recovered from sheep faeces

1980 ◽  
Vol 94 (2) ◽  
pp. 361-367 ◽  
Author(s):  
J. S. D. Bacon ◽  
A. H. Gordon
Keyword(s):  
Cell Wall ◽  
Linear Relationship ◽  
Linear Relation ◽  
Cell Walls ◽  
Sodium Methoxide ◽  
Sodium Ethoxide ◽  
Barley Straw ◽  
Maximum Effect ◽  
Acetyl Content ◽  
Sheep Rumen

SummaryTwo poorly digested materials, barley straw and grass cell wall residues recovered from sheep faeces, were treated with sodium ethoxide, methoxide or hydroxide under various conditions and the effects on their digestibilities studied by the nylon bag technique in the sheep rumen.Acetyl groups were removed during these treatments and the degree of deacetylation could be controlled by adjusting the amounts of reagents used, about 25 m-mole of base/g being required to produce the maximum effect. Sodium ethoxide in ethanol was the least effective of the reagents used: it did not remove acetyl groups from barley straw and left a larger proportion untouched in faeces cell walls than did sodium methoxide in methanol.Irrespective of the reagent employed digestibility increased with the progress of deacetylation and the two processes reached a maximum together, but there was not a linear relation between acetyl content and digestibility. In the case of straw treated with sodium hydroxide there appeared to be a linear relationship between digestibility and the amount of reagent applied, up to 20 m-moles/g straw.Phenolic ester groups were less susceptible to the reagents tested than acetyl groups. It is concluded that the action of the basic reagents is probably upon polysaccharides other than cellulose, that access to some regions of the cell walls may be limited by the solvent present, and that the linkages that restrict digestibility have a sensitivity to basic reagents similar to that of the acetyl ester groups present.

Synthesis of 2,2,4-Trimethyl-1,3-Pentanediol Monoisobutyrate

2014 ◽  
Vol 1033-1034 ◽  
pp. 76-80
Author(s):  
Xiang Jing Zhang ◽  
Peng Tao Wu ◽  
Zi Chao Jiang ◽  
Ting Ting Liu ◽  
Xiao Yang Gao ◽  
...  
Keyword(s):  
Reaction Time ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Reaction Temperature ◽  
Sodium Methoxide ◽  
Sodium Ethoxide ◽  
Water Soluble ◽  
Orthogonal Experiments ◽  
Paint Industry ◽  
Green Additive

2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (CS-12) is a non-water-soluble diol ester and an emerging green additive, widely used in paint industry. It can be synthesized by isobutyraldehyde with alkali as catalyst. In this article, several catalysts were studied for the synthesis of CS-12, for example, sodium hydroxide, calcium hydroxide, the mixture of sodium hydroxide and calcium hydroxide, sodium methoxide, the solution of sodium methoxide and methanol, and sodium ethoxide. Sodium hydroxide was finally selected as the optimal catalyst for the reaction. The effect of the amount of catalyst, reaction temperature and reaction time on the reaction were investigated by orthogonal experiments. The final optimal conditions are as follows: the catalyst dosage is 2 %, the reaction temperature is 50 °C, the reaction time is 4h. Under these conditions, the conversion of isobutyraldehyde is 93.10%, the selectivity of target product is 92.98%.

Electrical Properties of Na2O - SiO2 Dried Gels

1984 ◽  
Vol 32 ◽  
Author(s):  
D. Ravaine ◽  
J. Traore ◽  
L. C. Klein ◽  
I. Schwartz
Keyword(s):  
Thermogravimetric Analysis ◽  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Sodium Methoxide ◽  
Sodium Acetate ◽  
Room Temperature ◽  
Sodium Ethoxide ◽  
Residual Water ◽  
Protonic Conductivity ◽  
Drying Process

ABSTRACTGels with compositions Na2O-(1-x)SiO2 were prepared from tetraethylorthosilicate (TEOS) with sodium acetate and from tetramethylorthosilicate (TMOS) with sodium methoxide or TEOS with sodium ethoxide. After gelation (10 min.) the samples were slowly dried for about one month at room temperature. Thermogravimetric analysis (up to 500°C) in air and O2 atmosphere was performed. The electrical properties were studied in air by impedance spectroscopy during successive temperature cycles starting from room temperature dried gels of composition 0.10 Na2O 0.90 SiO2. Protonic conductivity appears to be eliminated after reaching the 2nd stage of the drying process (200°C). The activation energies for conduction and the conductivities show small discrepancies from known values for homogeneous glasses of equivalent compositions. Considering the effect of water on the conductivity of glasses prepared by the melting procedure, one can estimate the residual water content in the so-called dried gels to be close to 0.5 wt %.

Reaction of 4,4′-Bis(dimethylamino) triphenylmethyl Tetrafluoroborate with Alkoxide Ions. I. Determination of Ion-pair Dissociation Constant for Sodium Alkoxides

1975 ◽  
Vol 53 (11) ◽  
pp. 1537-1541 ◽  
Author(s):  
Kenneth T. Leffek ◽  
Andrej Suszka
Keyword(s):  
Dissociation Constant ◽  
Rate Constants ◽  
Sodium Methoxide ◽  
Dissociation Constants ◽  
Sodium Ethoxide ◽  
Activation Parameters ◽  
Ion Pair ◽  
Second Order ◽  
Carbonium Ion

The second-order rate constants have been determined for the reaction of 4,4′-bis(dimethylamino)triphenylmethyl tetrafluoroborate carbonium ion with sodium methoxide in methanol and sodium ethoxide in ethanol. The results have been used to evaluate the ion-pair dissociation constants for the two alkoxides. The activation parameters for the two reactions with the free alkoxide ions are also reported.

scholarly journals Methanolysis and ethanolysis of animal fats: A comparative study of the influence of alcohols

2011 ◽  
Vol 17 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Manuel García ◽  
Alberto Gonzaloa ◽  
Luis Sánchez ◽  
Jesús Arauzo ◽  
Catarina Simoes
Keyword(s):  
Methyl Ester ◽  
Sodium Methoxide ◽  
Sodium Ethoxide ◽  
Oxidation Stability ◽  
Natural Antioxidants ◽  
Product Yield ◽  
Animal Fats ◽  
Two Samples ◽  
Acceptance Range ◽  
Methyl Ester Content

Biodiesel from animal fats with methanol and ethanol was produced in the presence of sodium methoxide and sodium ethoxide as catalysts. Two samples of pork fats and one natural beef tallow were directly transesterified with a good final product yield; 87.7%, 86.7% and 86.3% for methanolysis and 78.4%, 82.6% and 82.7% for ethanolysis, respectively. Methyl ester content was also determined, being higher than 96.5 wt. % for all the samples prepared, the presence of natural C17:0 in animal fats makes it necessary to correct the method proposed in the standard EN 14103 (2003). Biodiesel density at 15 ?C of the samples was between 870 and 876 kg/m3, within the acceptance range of standard EN 14214, dynamic viscosity at 40 ?C of the produced biodiesels, in the range of 4.5 to 5.16 mm2/s, also fulfills requirements of EN 14214 standard. The iodine value is much lower than the superior limit established by EN 14214 standard but oxidation stability (OSI) is lower than the required limit, 6 h, of the standard, which can be attributed to the lack of natural antioxidants in tallows.

Immunocytochemical localization of desmin and vimentin in chick embryonic myocardial cells

1990 ◽  
Vol 48 (3) ◽  
pp. 448-449
Author(s):  
Yukiko Sugi
Keyword(s):  
Sodium Methoxide ◽  
Intermediate Filament Protein ◽  
Chick Embryos ◽  
Immunocytochemical Localization ◽  
Myocardial Cells ◽  
Immunofluorescence Study ◽  
Immunofluorescent Localization ◽  
Rabbit Igg ◽  
Semithin Sections ◽  
Filament Protein

In cultured skeletal muscle cells of chick, one intermediate filament protein, vimentin, is primarily formed and then synthesis of desmin follows. Coexistence of vimentin and desmin has been immunocytochemically confirmed in chick embryonic skeletal musclecells. Immunofluorescent localization of vimentin and desmin has been described in developing myocardial cells of hamster. However, initial localization of desmin and vimentin in early embryonic heart has not been reported in detail. By quick-freeze deep-etch method a loose network of intermediate filaments was revealed to exist surrounding myofibrils. In this report, immunocytochemical localization of desmin and vimentin is visualized in early stages of chick embryonic my ocardium.Chick embryos, Hamburger-Hamilton (H-H) stage 8 to hatch, and 1 day old postnatal chicks were used in this study. For immunofluorescence study, each embryo was fixed with 4% paraformaldehyde and embedded in Epon 812. De-epoxinized with sodium methoxide, semithin sections were stained with primary antibodies (rabbit anti-desmin antibody and anti-vimentin antibody)and secondary antibody (RITC conjugated goat-anti rabbit IgG).

An immunocytochemical study of maternal immunoglobulin localization in the suckling pig intestine

1990 ◽  
Vol 48 (3) ◽  
pp. 922-923
Author(s):  
László G. Kömüves ◽  
Donna S. Turner ◽  
Kathy S. McKee ◽  
Buford L. Nichols ◽  
Julian P. Heath
Keyword(s):  
Sodium Ethoxide ◽  
Intracellular Localization ◽  
Protein A ◽  
Tween 20 ◽  
Intestinal Epithelial ◽  
Immunocytochemical Study ◽  
Fish Skin ◽  
Newborn Piglets ◽  
Rabbit Igg ◽  
Fish Skin Gelatin

In this study we used colloidal gold probes to detect the intracellular localization of colostral immunoglobulins in intestinal epithelial cells of newborn piglets.Tissues were obtained from non-suckled newborn and suckled piglets aged between 1 hour to 1 month. Samples were fixed in 2.5 % glutaraldehyde, osmicated and embedded into Spurr’s resin. Thin (80 nm) sections were etched with 5% sodium ethoxide for 5 min, washed and treated with 4 % sodium-m-periodate in distilled water for 30 min. The sections were then first incubated with blocking buffer (2 % BSA, 0.25 % fish skin gelatin, 0.5 % Tween 20 in 10 mM Trizma buffer, pH=7.4 containing 500 mM NaCl) for 30 min followed by the immunoreagents diluted in the same buffer, 1 hr each. For the detection of pig immunoglobulins a rabbit anti-pig IgG antiserum was used followed by goat anti-rabbit IgG-Au10 or protein A-Au15 probes.

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