THE DIELECTRIC CONSTANT AND SALT EFFECTS UPON THE ACID HYDROLYSIS OF ETHYL FORMATE

1952 ◽  
Author(s):  
NAVIN P. SHAH ◽  
EDWARD S. AMIS
Keyword(s):  
Dielectric Constant ◽  
Acid Hydrolysis ◽  
Ethyl Formate ◽  
Salt Effects ◽  
Hydrolysis Of

Acid Hydrolysis of an Ether Bond Assisted by the Neighbouring Amide Group: Effects Induced by Salts and by Structural Changes Part 61-5

2002 ◽  
Vol 2002 (5) ◽  
pp. 199-200 ◽  
Author(s):  
Antonio Arcelli ◽  
Francesca Paradisi ◽  
Gianni Porzi ◽  
Samuele Rinaldi ◽  
Sergio Sandri
Keyword(s):  
Acid Hydrolysis ◽  
Structural Changes ◽  
Activation Parameters ◽  
Amide Group ◽  
Side Chain ◽  
Salt Effects ◽  
Methyl Group ◽  
Ether Bond ◽  
Thermodynamic Activation Parameters ◽  
Hydrolysis Of

The acid hydrolysis of 1 assisted by the neighbouring amide group was kinetically investigated and salt effects were studied; the thermodynamic activation parameters calculated for the acid hydrolysis of other substrates (3–6) indicate that the methyl group in the side chain works on the enthalpic or on the entropic factor depending on the size of ring formed.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

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