Kinetics and Mechanism of Desulfurization Reaction of 1-Methyl-2-phenylquinazoline-4(1H)-thiones

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Title:Kinetics and Mechanism of Desulfurization Reaction of 1-Methyl-2-phenylquinazoline-4(1H)-thiones
Creators:
Hanusek, Jiří
Sedlák, Miloš
Keder, Roman
Štěrba, Vojeslav
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 69, 12, pp. 2212-2222
Uncontrolled Keywords:Kinetics, Mechanism, Hydrolysis, Quinazolines, Quinazoline-4(1<i>H</i>)-thiones, Methanolysis, Desulfurization

Abstract

Kinetics and mechanism of desulfurization reaction of 1-methyl-2-(substituted phenyl)-quinazoline-4(1<i>H</i>)-thiones in sodium methoxide solutions have been studied, giving the corresponding 1-methyl-2-(substituted phenyl)quinazolin-4(1<i>H</i>)-ones. The reaction proceeds in two steps. The first step involves splitting off of sulfur in the form of SH<sup>-</sup> and is much faster than the second step, whose rate is almost independent of the concentration of water in methanol. At lowest concentrations of methoxide, the rate of the first step increases linearly, but at higher concentrations a gradual decrease in the rate takes place. The rate of the second step, i.e. the transformation of the intermediate formed <strong>In</strong> into 1-methyl-2-(substituted phenyl)quinazolin-4(1<i>H</i>)-one (<strong>2a</strong>-<strong>2e</strong>), is independent of the methoxide concentration but increases with increasing concentration of water in methanol. On the basis of the kinetic dependences, the mechanism for both steps of desulfurization and the structure of intermediate <strong>In</strong> were proposed. <p>

Title:Kinetics and Mechanism of Desulfurization Reaction of 1-Methyl-2-phenylquinazoline-4(1H)-thiones
Creators:
Hanusek, Jiří
Sedlák, Miloš
Keder, Roman
Štěrba, Vojeslav
Uncontrolled Keywords:Kinetics, Mechanism, Hydrolysis, Quinazolines, Quinazoline-4(1<i>H</i>)-thiones, Methanolysis, Desulfurization
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:69
Number:12
Page Range:pp. 2212-2222
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20042212UNSPECIFIED
ID Code:2331
Item Type:Article
Deposited On:06 Feb 2009 17:17
Last Modified:06 Feb 2009 16:17

Citation

Hanusek, Jiří; Sedlák, Miloš; Keder, Roman; Štěrba, Vojeslav (2004) Kinetics and Mechanism of Desulfurization Reaction of 1-Methyl-2-phenylquinazoline-4(1H)-thiones. Collection of Czechoslovak Chemical Communications, 69 (12). pp. 2212-2222. ISSN 0010-0765

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