PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XXIII. CONDENSATION OF THE ISOMERIC 2,3-BUTANEDIOLS WITH ETHYL ACETOACETATE

1947 ◽  
Vol 25b (5) ◽  
pp. 423-429 ◽  
Author(s):  
A. C. Neish
Keyword(s):  
Hydrochloric Acid ◽  
Ethyl Ester ◽  
Ethyl Acetoacetate ◽  
Free Acid ◽  
Butyl Ester ◽  
Melting Points ◽  
First Time

levo-2,3-Butanediol will condense with ethyl acetoacetate in the presence of hydrochloric acid to give the ethyl ester of levo-2,4,5-trimethyl-2-carboxymethyl-1,3-dioxacyclopentane (I) (yield 48%) from which the free acid may be obtained. If p-toluenesulphonic acid is used as the catalyst and the condensation is carried out in boiling butanol with continuous removal of water, the butyl ester of (I) is obtained (yield 87%). Compounds described for the first time are levo-, dl-, and meso-2,4,5-trimethyl-2-carboxymethyl-1,3-dioxacyclopentanes, their n-butyl and p-bromophenacyl esters (melting points 74.5°, 76°, and 76 °C., respectively) and the ethyl ester of the levo-isomer.

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

2018 ◽  
Author(s):  
Nicolò Bontempi ◽  
Irene Vassalini ◽  
Stefano Danesi ◽  
Matteo Ferroni ◽  
Paolo Colombi ◽  
...  
Keyword(s):  
Critical Role ◽  
Raman Laser ◽  
Core Shell ◽  
Thermal Coupling ◽  
Melting Points ◽  
Experimental Proof ◽  
Weakly Coupled ◽  
Light Management ◽  
Laser Sources ◽  
First Time

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>

scholarly journals THE ANTIBACTERIAL ACTIVITY OF COMPOUNDS FROM LEAVES OF ARCTOSTAPHYLOS UVA-URS

2018 ◽  
pp. 53-60
Author(s):  
Владимир (Vladimir) Александрович (Аleksandrovich) Куркин (Kurkin) ◽  
Татьяна (Tat'yana) Константиновна (Konstantinovna) Рязанова (Ryazanova) ◽  
Александр (Аleksandr) Викторович (Viktorovich) Жестков (Zhestkov) ◽  
Артем (Аrtem) Викторович (Viktorovich) Лямин (Lyamin) ◽  
Елена (Elena) Владимировна (Vladimirovna) Авдеева (Avdeeva) ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Ethyl Ester ◽  
Uv Spectroscopy ◽  
Alcoholic Extract ◽  
Gram Positive Bacteria ◽  
Chemical Structures ◽  
Main Component ◽  
First Time ◽  
And Staphylococcus Aureus ◽  
Perm Region

The aim of this paper is the isolation of individual compounds, which are caused the antibacterial activity of the leaves of the bearberry [Arctostaphylos uva-ursi (L.) Spreng.]. The leaves of Arctostaphylos uva-ursi, collected in Perm region, there were extracted with 70% ethanol, the obtained water-alcoholic infusion there was evaporated in vacuum.By means of the chromatographic methods with the using of silica gel 40/100 and eluent systems (chloroform and ethanol in several ratio) from the evaporated water-alcoholic extract of the leaves of Arctostaphylos uva-ursi, a substance with antibacterial activity, ethyl ester of p-digallic acid, which is a new natural compound, was isolated along with arbutin ((1-О-b-D-glucopyranoside of hydroquinone) from the leaves of this plant. The chemical structures of the ethyl ester of p-digallic acid and arbutin were established with the using of data of 1H-NMR-spectroscopy, UV-spectroscopy and mass-spectrometry..The antibacterial activity of ethyl ester of p-digallic acid against test cultures of gram-positive bacteria Bacillus cereus and Staphylococcus aureus, gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa for the first time was determined. By antibacterial activity, arbutin was inferior not only to ethyl ester of p-digallic acid, but also to decoction from the leaves of the bearberry. Consequently, the ethyl ester of p-digallic acid is one in main component, which is take the contribution in the antibacterial activity of the decoction and other preparations of the leaves of Arctostaphylos uva-ursi.

Pyrimidine Derivatives and Related Compounds, V Synthesis of Some Isoxazolo [2,3-a] pyrimidines. A New Ring System

1977 ◽  
Vol 32 (3) ◽  
pp. 311-314 ◽  
Author(s):  
Mohamed Hilmy Elnagdi ◽  
Ezzat Mohamed Kandeel ◽  
Kamal Usef Sadek
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Ethyl Acetoacetate ◽  
Pyrimidine Derivative ◽  
Ring System ◽  
The Other ◽  
Acid Mixture ◽  
Pyrimidine Derivatives ◽  
Benzoyl Isothiocyanates ◽  
Related Compounds

3-Amino-5-phenyl-4-phenylazoisoxazole (1) reacts with ethyl acetoacetate to yield the corresponding ethyl isoxazolylaminocrotonate derivative (2) which could be thermally cyclized into the isoxazolopyrimidine derivative (4). On the other hand, condensation of 1 with ethoxymethylenemalononitrile has resulted in the formation of the aminoethylene derivative (5).Compound 1 reacted with acrylonitrile to yield the isoxazolo[2,3-a]pyrimidine derivative (6). The latter was converted into the corresponding exo derivative (8) by the action of acetic acid-hydrochloric acid mixture.Compound 1 also reacted with methoxycarbonyl-, ethoxycarbomyl- and benzoyl isothiocyanates to yield the isoxazolylthioureas (10a, b) and (11), respectively. The reaction of 2 with acetic acid-hydrochloric acid and with phenylhydrazine is reported.

scholarly journals Preparation of Poly(Hydroxamic Acid) for Separation of Zr/Y, Sr System

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Khaled F. Hassan ◽  
Shaban A. Kandil ◽  
Hossam M. Abdel-Aziz ◽  
Tharwat Siyam
Keyword(s):  
Hydrochloric Acid ◽  
Cation Exchange ◽  
Column Chromatography ◽  
Hydroxamic Acid ◽  
Acetate Buffer ◽  
Purification Process ◽  
Citrate Buffer ◽  
Adsorption Behaviors ◽  
Cation Exchange Column ◽  
First Time

Poly(hydroxamic acid) resin (PHA) was prepared by modification of polyacrylamide (PAAm) prepared through -irradiation technique and used for the first time in separation of Zr(IV) from Y(III) and Sr(II) as a simulation mode for the purification of89Zr from its parents (Y or Sr). The adsorption behaviors of zirconium, yttrium, and strontium on the prepared PHA resin in different media, namely, hydrochloric acid, acetate buffer, and citrate buffer were studied as a function of pH. In addition, in cation-exchange column chromatography experiments using PHA, three different eluants, namely,  mol/L HCl, acetate buffer pH 3.5, and 2 mol/L HCl, were employed for elution of Zr(IV), Y(III) and Sr(II), respectively, where Zr(IV), Y(III) and Sr(II) were eluted in amounts of 80%, 99.9%, and 100%, respectively. The purification process of Y(III) from Zr(IV) was carried out using regenerated PHA.

scholarly journals Solid state and sub-cooled liquid vapour pressures of cyclic aliphatic dicarboxylic acids

2010 ◽  
Vol 10 (10) ◽  
pp. 23017-23043 ◽  
Author(s):  
A. M. Booth ◽  
W. J. Montague ◽  
M. H. Barley ◽  
D. O. Topping ◽  
G. McFiggans ◽  
...  
Keyword(s):  
Solid State ◽  
Dicarboxylic Acids ◽  
Estimation Methods ◽  
Melting Points ◽  
Straight Chain ◽  
Scanning Calorimetry ◽  
Knudsen Effusion ◽  
Knudsen Effusion Mass Spectrometry ◽  
First Time ◽  
Selection Of

Abstract. Knudsen Effusion Mass Spectrometry (KEMS) has been used to measure for the first time the solid state vapour pressures of a series of aliphatic cyclic dicarboxylic acids with increasing ring size. Additionally the atmospherically important compounds; cis-pinonic acid and levoglucosan were also measured. Differential Scanning Calorimetry (DSC) was used to measure melting points, enthalpies and entropies of fusion, which were used to determine sub-cooled liquid vapour pressures for the compounds. The sub-cooled liquid vapour pressure of straight chain, branched and cyclic dicarboxylic acids was compared to a selection of estimation methods.

Application of Fluazifop-P, Haloxyfop, and Quizalofop by Sprinkler Irrigation

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Charles B. Guy ◽  
Ronald E. Talbert ◽  
James A. Ferguson ◽  
David H. Johnson ◽  
Marilyn R. McClelland
Keyword(s):  
Methyl Ester ◽  
Ethyl Ester ◽  
Butyl Ester ◽  
Sprinkler Irrigation ◽  
Field Studies ◽  
Root Uptake ◽  
Irrigation Application ◽  
Large Crabgrass ◽  
Spray Applications

In field studies, sprinkler irrigation application of the butyl ester of fluazifop-P, the methyl ester of haloxyfop, and the ethyl ester of quizalofop controlled large crabgrass as well as conventional spray applications. In greenhouse investigations, root uptake of the herbicides from sprinkler irrigation applications injured large crabgrass more than root uptake from conventional applications, but large crabgrass injury from shoot uptake was equal with sprinkler irrigation and conventional applications. Droplets with dilute concentrations of herbicide and crop oil, simulating sprinkler irrigation, were more active when applied to the whorl or second leaf than to the first leaf of large crabgrass. An increase in concentration of nonemulsified oil in the treatment solution increased herbicide deposition and retention.

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

2018 ◽  
Author(s):  
Nicolò Bontempi ◽  
Irene Vassalini ◽  
Stefano Danesi ◽  
Matteo Ferroni ◽  
Paolo Colombi ◽  
...  
Keyword(s):  
Critical Role ◽  
Raman Laser ◽  
Core Shell ◽  
Thermal Coupling ◽  
Melting Points ◽  
Experimental Proof ◽  
Weakly Coupled ◽  
Light Management ◽  
Laser Sources ◽  
First Time

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>

Lymphatic transport of eicosapentaenoic and docosahexaenoic acids as triglyceride, ethyl ester and free acid, and their effect on cholesterol transport in rats

Life Sciences ◽  
1993 ◽  
Vol 52 (16) ◽  
pp. 1371-1379 ◽  
Author(s):  
Ikuo Ikeda ◽  
Youji Imasato ◽  
Hiroshi Nagao ◽  
Eiji Sasaki ◽  
Michihiro Sugano ◽  
...  
Keyword(s):  
Ethyl Ester ◽  
Free Acid ◽  
Lymphatic Transport ◽  
Cholesterol Transport ◽  
Docosahexaenoic Acids

Temperature Effects on Translocation Patterns of Several Herbicides within Quackgrass (Agropyron repens)

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 545-552 ◽  
Author(s):  
K. Neil Harker ◽  
Jack Dekker
Keyword(s):  
Methyl Ester ◽  
Ethyl Ester ◽  
Growth Temperature ◽  
Temperature Effects ◽  
Butyl Ester ◽  
Effect Of Temperature ◽  
Night Temperature ◽  
Rhizome Growth ◽  
Temperature Regimes ◽  
Increasing Temperature

A growth cabinet study was conducted to evaluate the effect of temperature on the distribution of several herbicides in quackgrass. Uniformly labeled14C-sucrose and the radiolabeled herbicides glyphosate, sethoxydim, cloproxydim, the butyl ester of fluazifop, the methyl ester of haloxyfop, and the ethyl ester of quizalofop were applied to quackgrass grown at three day / night temperature regimes (10/5, 20/15, and 30/25 C). Seven days after treatment the plants were harvested, lyophilized, and later sectioned, mapped, and oxidized in preparation for14C quantification. Quackgrass rhizome growth was more vigorous at 20/15 than 30/25 or 10/5 C. of the herbicides tested, haloxyfop was the most inhibitory to rhizome growth. Temperature increases from 10/5 to 20/15 or from 20/15 to 30/25 C resulted in more translocation to shoots. Increasing temperature had various effects on translocation to rhizomes depending on the chemical applied. At all three temperature regimes, more14C was recovered from distal than basal buds in plants treated with14C-sethoxydim. In contrast, at all three temperature regimes, similar amounts of14C were recovered from the distal and basal buds of plants treated with 14-C-sucrose.

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