%0 Journal Article
%T Regioselectivity of Electrophilic Attack on 4-Methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one. Part 1: Reactions at the Sulfur Atom
%A Walid Fathalla
%A Michal £żajan
%A Pavel Pazdera
%J Molecules
%D 2001
%I MDPI AG
%R 10.3390/60600557
%X The regioselectivity of the model compound 4-methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one (3) towards different electrophiles was studied. Compound 3 reacts with alkyl and aryl halides to give the corresponding S-substituted derivatives. The reaction of the model thioamide with acyl halides proceeds by the formation of kinetically controlled S-acyl derivatives followed by a transacylation reaction to give the N2-acyl derivatives as thermodynamically controlled products. Theoretical DFT computational studies supported the explanation of these results. The synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR, and mass spectroscopy.
%K Cyclic thioamides
%K regioselective reactions
%K 4-methyl-1-thioxo- 1
%K 2
%K 4
%K 5-tetrahydro[1
%K 2
%K 4]triazolo[4
%K 3-a]quinazolin-5-one
%K DFT computational studies
%U http://www.mdpi.com/1420-3049/6/6/557