Acid‐Catalysed Cyclization of <i>o</i> ‐Aminobenzamide with <i>α</i> ‐Oxodithioesters: A Divergent and Regioselective Synthesis of Quinazolinones and 1,3‐Benzothiazinones
Kuppalli R. Kiran, Toreshettahally R. Swaroop, Ramesh Preetham, Paris E. Georghiou, Kanchugarakoppal S. Rangappa, Maralinganadoddi P. Sadashiva
Abstract
Abstract Acid catalysed cyclization of o ‐aminobenzamide and α ‐oxodithioesters in a highly regioselective fashion to give 2‐aroylquinazolin‐4(3 H )‐ones and 2‐aroyl‐4 H ‐benzo[d][1,3]thiazin‐4‐ones by switching the reaction medium from DMF to acetic acid. Further, the generality of the stabilised protocols was tested with various functionalities. The range of yields for the quinazolinones and 1,3‐thiazinone are 57–67 % and 70–81 %, respectively. Probable mechanisms for the formation of the two series of products are proposed from control experiments.
Topics & Concepts
RegioselectivityAcetic acidChemistryCatalysisCombinatorial chemistryGeneralityMedicinal chemistryStereochemistryOrganic chemistryPsychologyPsychotherapistQuinazolinone synthesis and applicationsSynthesis and Biological EvaluationMulticomponent Synthesis of Heterocycles