Base-Promoted [5 + 1 + 3] Cascade Cyclization of <i>o</i>-Nitrochalcones, Elemental Sulfur, and Guanidine to Benzo[4,5]thieno[3,2-<i>d</i>]pyrimidine Frameworks
Juan Wan, Shuntao Huang, Zhou Zhang, Qin Wu, Zhuoyu Wang, Chao Huang
Abstract
An unexpected [5 + 1 + 3] cascade cyclization to the preparation of benzo[4,5]thieno[3,2- d ]pyrimidine derivatives has been disclosed. In the new protocol, o -nitrochalcones reacted with elemental sulfur and guanidine promoted by NaOH, which reacted in EtOH for 20 min, providing structurally diverse benzo[4,5]thieno[3,2- d ]pyrimidines with good yields (77–89%) and wide substrate compatibility (33 examples).
Topics & Concepts
ChemistryGuanidinePyrimidineSulfurCascadeCompatibility (geochemistry)Base (topology)Combinatorial chemistryMedicinal chemistryStereochemistryOrganic chemistryChromatographyGeologyMathematical analysisMathematicsGeochemistrySulfur-Based Synthesis TechniquesSynthesis of heterocyclic compoundsSynthesis and Characterization of Heterocyclic Compounds