- 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
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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 N 2-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.
- Fathalla, Walid,Cajan, Michal,Pazdera, Pavel
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- Synthesis and Structure of Some Condensed Quinazolines
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Condensation of 2-hydrazino-4(3H)-quinazolinone (1) with bielectrophilic reagents gives the corresponding triazoloquinazolines 8, the structures of which were established by selective synthesis through deamination of their N-amino derivatives.The synthesis of methyl-substituted derivatives of these angular tricyclic systems and their linear isomers was also achieved starting with 3-methyl- and 1-methyl-2-hydrazinoquinazolinone.
- Badawy, Mohamed A.,Abdel-Hady, Sayed A.,Mahmoud, Ahmed H.,Ibrahim, Yehia A.
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p. 815 - 817
(2007/10/02)
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