74375-03-4Relevant articles and documents
Kinetics and mechanism of desulfurization reaction of 1-methyl-2- phenylquinazoline-4(1H)-thiones
Hanusek, Jiri,Sedlak, Milos,Keder, Roman,Sterba, Vojeslav
, p. 2212 - 2222 (2007/10/03)
Kinetics and mechanism of desulfurization reaction of 1-methyl-2- (substituted phenyl)-quinazoline-4(1H)-thiones in sodium methoxide solutions have been studied, giving the corresponding 1-methyl-2-(substituted phenyl)quinazolin-4(1H)-ones. The reaction proceeds in two steps. The first step involves splitting off of sulfur in the form of SH- 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 In into 1-methyl-2-(substituted phenyl)quinazolin-4(1H)-one (2a-2e), 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 In were proposed.
Synthesis of substituted 2-benzoylaminothiobenzamides and their ring closure to substituted 2-phenylquinazoline-4-thiones
Hanusek, Jiri,Hejtmankova, Ludmila,Kubicova, Lenka,Sedlak, Milos
, p. 323 - 337 (2007/10/03)
Acylation of 2-aminothiobenzamide or 2-methylaminothiobenzamide with substituted benzoyl chlorides has been used to synthesise the corresponding 2-benzoyl-aminothiobenzamides whose subsequent sodium methoxide-catalysed ring closure gives the corresponding quinazoline-4-thiones. These compounds were characterised by means of their 1H- and 13C-NMR spectra. The preferred tautomeric form of selected compounds has been discussed on the basis of their 13C-NMR, IR and Raman spectra. It has been found that in the given medium 1-methyl-quinazoline-4-thiones undergo a replacement of the sulphur substituent by oxygen giving 1-methyl-quinazoline-4-ones. In strong acid media, 2-benzoylaminothiobenzamide is cyclised through its sulphur atom to give 2-phenylbenzo[d-1,3]thiazin-4-one.