Synthesis of 3-isoxazolols revisited. Diketene and (β-ketoesters as starting materials

1984 ◽  
Vol 62 (10) ◽  
pp. 1940-1944 ◽  
Author(s):  
Niels Jacobsen ◽  
Hans Kolind-Andersen ◽  
Jens Christensen
Keyword(s):  
Mineral Acid ◽  
Strong Mineral Acid ◽  
Made In

3-Isoxazolols can be made in good yields from β-ketoesters or diketene and hydroxylamine, provided that pH is kept at about 10 throughout the reaction, and that the reaction mixture is quenched with an excess of strong mineral acid. This suppresses the formation of 5-isoxazolones, which are otherwise normally the main products of the reaction.

Racemization of free and protein-bound amino acids in strong mineral acid

2009 ◽  
Vol 18 (5) ◽  
pp. 500-505 ◽  
Author(s):  
Remy Liardony ◽  
Rolf Jost
Keyword(s):  
Amino Acids ◽  
Mineral Acid ◽  
Strong Mineral Acid

General vs. Specific Acid-Base Catalysis in Strong Mineral Acid Solution. Aromatic Decarbonylation1

1958 ◽  
Vol 80 (7) ◽  
pp. 1755-1761 ◽  
Author(s):  
W. M. Schubert ◽  
Philip C. Myhre
Keyword(s):  
Acid Solution ◽  
Mineral Acid ◽  
Base Catalysis ◽  
Acid Base ◽  
Mineral Acid Solution ◽  
Strong Mineral Acid

Polarography of titanium in strong mineral acid media

1956 ◽  
Vol 15 ◽  
pp. 294-300 ◽  
Author(s):  
James J. Lingane ◽  
John H. Kennedy
Keyword(s):  
Mineral Acid ◽  
Acid Media ◽  
Strong Mineral Acid

Note on an Analysis of Human Gastric Juice

1897 ◽  
Vol 21 ◽  
pp. 298-298
Author(s):  
W. R. Lang
Keyword(s):  
Lactic Acid ◽  
Hydrochloric Acid ◽  
Gastric Juice ◽  
Methyl Violet ◽  
Mineral Acid ◽  
Alcoholic Solution ◽  
Free Hydrochloric Acid ◽  
Dilute Solution ◽  
Blue Coloration ◽  
Made In

In the autumn of 1895 I received from Professor M'Ewen several samples of gastric juice marked “Chalmers' Gastrostomy.” The samples were obtained under most favourable circumstances, being drawn off through an aperture made in the abdomen and stomach of the patient; the juice was almost pure, and nearly free from suspended matter. My analysis was mainly directed towards ascertaining whether or not free hydrochloric acid was a constituent of the fluid, and the following were the reactions I employed:—(1) With methyl violet the sample gave a distinct blue coloration, showing the presence of a mineral acid. Supposing the acidity to be due to lactic acid, this reaction would not take place, as on trying a dilute solution of lactic acid with this reagent no blue colour was produced.(2) On treating an alcoholic solution of phloroglucin and vanillin (1 grm. of the former and ½ grm. of the latter made up with 50 cc.'s rectified spirits) with the gastric juice and evaporating slowly on a water-bath, a red colour was produced. Dilute hydrochloric acid gave the same result; lactic acid none.In the opinion of some authorities the presence of free hydrochloric acid is attributed to the decomposition on evaporation of the chlorides present in the gastric juice by free lactic acid. With a view to ascertain whether this could happen or not, I evaporated solutions of chloride of calcium and lactic acid with both of the above reagents with a negative result.

Comparison of the Behavior of Trace Elements During Acid Leaching of Ashes from Several Coals

1986 ◽  
Vol 86 ◽  
Author(s):  
J. S. Watson
Keyword(s):  
Trace Elements ◽  
Fly Ash ◽  
Amorphous Materials ◽  
Acid Leaching ◽  
Initial Step ◽  
Mineral Acid ◽  
Chemical Analyses ◽  
Leaching Behavior ◽  
Original Distribution ◽  
Strong Mineral Acid

ABSTRACTThe leaching of fly ash from eastern U.S. coals with strong mineral acid is the initial step in a series of potential processes for producing useful and marketable materials from the ash. This initial leaching step removes most, or all, of the more soluble (generally amorphous) materials from the ash and leaves an inert residue, believed to be mostly mullite and silica. Chemical analyses of the leachate and the residual inert materials indicate the original distribution of the trace elements in the phases. Significant differences in crystallography, composition and leaching behavior have been noted in ash samples from coals from various regions, of various types, and sometimes even in ash samples from the same or similar coals. Trace element analyses of fly ash leachates provide a useful means of studying coal characteristics and of determining how the trace elements are incorporated in various types of fly ashes.

scholarly journals A Gasometric Procedure to Measure Residual Lime in Container Substrates

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1685-1689 ◽  
Author(s):  
Jinsheng Huang ◽  
Paul R. Fisher ◽  
William R. Argo
Keyword(s):  
Crop Production ◽  
Ph Control ◽  
Application Rate ◽  
Mineral Acid ◽  
Test Protocol ◽  
Ph Change ◽  
Ph Titration ◽  
Strong Mineral Acid ◽  
Substrate Ph ◽  
Over Time

Unreacted residual limestone in the container substrate is key in buffering pH change over time. Our goal was to develop a substrate test protocol to measure residual lime [in units of CaCO3 equivalent (CCE)] by applying a strong mineral acid (HCl) to a substrate sample and measuring the evolved CO2 gas with a gasometric method based on a Chittick apparatus. In one experiment, CaCO3 was added to a substrate that had previously been neutralized to pH 7.35 with Ca(OH)2 so that there would be minimal CaCO3 reaction with the substrate at this high pH. The gasometric method was then used to estimate residual CCE. Measured CCE and applied CaCO3 were similar, indicating reliable CCE estimation. In a second experiment, a pH titration method was used to quantify the relationship between substrate-pH and milliequivalents of reacted base and provided an additional validation of the estimated reacted and residual CCE. The gasometric method demonstrated declining residual CCE over time as a dolomitic limestone reacted to raise substrate-pH and increasing residual CCE as applied CaCO3 concentration increased. Residual CCE in a substrate is an important property that should be considered for pH control and management in greenhouse crop production. Our results indicate that the gasometric system may be useful for optimizing lime application rate, lime source, or management of residual CCE during crop production.

The Iodination of Aromatic Compounds. III. Halogenation of Aromatic Ethers in the Presence of Hydrogen Peroxide

1949 ◽  
Vol 2 (4) ◽  
pp. 595
Author(s):  
L Jurd
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Aromatic Compounds ◽  
Potassium Bromide ◽  
Mineral Acid ◽  
Alcoholic Solution ◽  
Strong Mineral Acid ◽  
High Yields

Aromatic ethers are rapidly iodinated when treated in alcoholic solution with iodine and hydrogen peroxide in the presence of a strong mineral acid. High yields of the mono-iodo-derivatives are obtained with anisole and the 2-naphthyl ethers whilst both mono- and diiodination occur readily with the dimethoxybenzenes. In the absence of a mineral acid the reaction is very slow and only poor yield of the iodo-ethers result. A convenient process is described for the preparation of p-chloro- and p-bromo- anisole, and other chloro- and bromo-ethers, the ether being treated with hydrochloric acid and with potassium bromide and sulphuric acid respectively in the presence of hydrogen peroxide.

Acidic Precipitation in South-Central Ontario: Recent Observations

1978 ◽  
Vol 35 (6) ◽  
pp. 809-815 ◽  
Author(s):  
P. J. Dillon ◽  
D. S. Jeffries ◽  
W. Snyder ◽  
R. Reid ◽  
N. D. Yan ◽  
...  
Keyword(s):  
New England ◽  
Mineral Acid ◽  
Buffering Capacity ◽  
Acidic Precipitation ◽  
South Central ◽  
Frequent Event ◽  
Strong Mineral Acid ◽  
Acidic Rain ◽  
Time Required ◽  
Northeastern Usa

Precipitation in south-central Ontario, with mean pH between 3.95 and 4.38 and frequent event pH's of < 4.0, is more acidic than that in the Sudbury, Ontario, region and in Scandinavia, and as acidic as that in the northeastern USA. As in New England, a major component of the total acidity is strong mineral acid. Because most lakes in south-central Ontario have very low buffering capacities (10–200 μeq∙L−1), high acid loadings are likely to lead to acidification of many lakes and streams in the forseeable future. Although it is not yet possible to estimate the time required for this to happen, there is already some evidence of declining buffering capacity in a few lakes. Key words: acidic rain, buffering capacity, acidic lakes, precipitation, alkalinity

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