Beilstein J. Org. Chem.2010,6, 1056–1060, doi:10.3762/bjoc.6.120
Nimalini D. Moirangthem Warjeet S. Laitonjam Department of Chemistry, Manipur University, Canchipur 795 003, Manipur, India 10.3762/bjoc.6.120 Abstract A new and facile synthesis of 2-thioxoquinazolin-4-ones by introducing a benzenoid system in the pyrimidine moiety by reacting ethoxymethylene
derivatives of 1,3-diarylthiobarbituric acids (DTBA) with active methylene compounds, such as malononitrile and ethyl cyanoacetate, in presence of ZnCl2 has been developed.
Keywords: benzenoid; ethylcyanoacetate; malononitrile; pyrimidine; 2-thioxoquinazolin-4-ones; Introduction
Quinazolines and derivatives
-thioxoquinazolin-4-ones, as most of the methods reported are for quinazolin-2,4(1H,3H)-diones. Recently, Saeed et al. [18] reported the base catalyzed intramolecular nucleophilic cyclization of substituted thioureas in the presence of DMF to afford 2-thioxoquinazolin-4-ones. The preparation of 2-thioxoquinazolin-4
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Graphical Abstract
Scheme 1:
Synthesis of 2, reagents and conditions: (i) CH2(CN)2, NH4OAc/AcOH, reflux, ZnCl2 (ii) H+/H2O.