Dissolution Kinetics of Some Alkyl Derivatives of Acetaminophen

1978 ◽  
Vol 4 (6) ◽  
pp. 529-535 ◽  
Author(s):  
J. C. Dearden ◽  
N. C. Patel
Keyword(s):  
Dissolution Kinetics ◽  
Alkyl Derivatives ◽  
Kinetics Of ◽  
Derivatives Of

Reactions of ethyl 2-alkyl-3-oxobutanoate with thiourea and methylthiourea

1983 ◽  
Vol 48 (7) ◽  
pp. 1872-1877 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Vojeslav Štěrba
Keyword(s):  
Reaction Mechanism ◽  
Dissociation Constants ◽  
Reaction Rates ◽  
Medium Effects ◽  
Alkyl Derivatives ◽  
Alkyl Groups ◽  
Independent Synthesis ◽  
Kinetics Of ◽  
Derivatives Of

The reaction of ethyl 3-oxobutanoate with N-methylthiourea in alkoxide medium gives a mixture (1 : 20) of 1,6-dimethyl-2-thiouracil and 3,6-dimethyl-2-thiouracil: the latter isomer has been isolated from the mixture and the former isomer has been prepared by independent synthesis. Dissociation constants of ethyl 2-alkyl-3-oxobutanoates (alkyl = methyl, butyl, or isopropyl) have been measured in methanol. Reaction of these esters with thiourea and N-methylthiourea gives the corresponding alkyl derivatives of 6-methyl-2-thiouracil. Kinetics of these reactions have been measured in methoxide medium. Effects of the alkyl groups on the reaction rates have been investigated, and a reaction mechanism is suggested.

7-O-Alkyl derivatives of daunomycinone

1984 ◽  
Vol 49 (1) ◽  
pp. 313-319 ◽  
Author(s):  
Věra Přikrylová ◽  
Petr Sedmera ◽  
Josef V. Jizba ◽  
Jindřich Vokoun ◽  
Helena Lipavská ◽  
...  
Keyword(s):  
H Nmr ◽  
Toluenesulfonic Acid ◽  
Alkyl Derivatives ◽  
Derivatives Of

Reaction of daunomycinone (I) with alcohols and p-toluenesulfonic acid produces a mixture (~3 : 1) of its (7S)- and (7R)-O-alkyl derivatives II-IX. According to the 1H NMR evidence, the alicyclic ring exists in the 9H8 conformation in (7R)-O-alkyl derivatives, on the contrary to (7S)-epimers and 7-epi-daunomycinone that adopt the 8H9 conformation.

Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský
Keyword(s):  
Reaction Rate ◽  
Kinetic Isotope ◽  
Acid Base Equilibrium ◽  
Mineral Acids ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Ph Scale ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

Polarized fluorescense of alkyl derivatives of fluorescein, MitoFluo and C8-Fl, in solutions with liposomes

2020 ◽  
Author(s):  
D.M. Beltukova ◽  
V.P. Belik ◽  
Y.N. Antonenko ◽  
A.A. Bogdanov ◽  
G.A. Korshunova ◽  
...  
Keyword(s):  
Alkyl Derivatives ◽  
Derivatives Of
Sign in / Sign up

Export Citation Format

Share Document