Biginelli and Hantzsch-type reactions leading to highly functionalized dihydropyrimidinone, thiocoumarin, and pyridopyrimidinone frameworks via ring annulation with β-oxodithioesters.
An efficient and highly convergent route to dihydropyrimidinones (DHPMs) and hitherto unreported dihydropyridopyrimidinones has been developed by one-pot, three-component cyclocondensation of aromatic aldehydes, β-oxodithioesters, and urea/6-amino-1,3-dimethyluracil in the presence of recyclable SiO2-H2SO4. On the other hand, salicylaldehyde, β-oxodithioester, and urea reacted under similar conditions to afford the 3-aroyl/heteroaroyl-2H-chromen-2-thiones in high yields instead of Biginelli product. The attractive feature of this approach is the synthesis of three important bioactive heterocyclic frameworks from the same β-oxodithioester under the similar reaction conditions, making this new strategy highly useful in diversity-oriented synthesis (DOS).
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
Ganesh Chandra
GC
Nandi
Subhasis
S
Samai
Maya Shankar
MS
Singh
D002384:Catalysis; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011744:Pyrimidinones / Q000138:chemical synthesis* / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry
C479868:6-amino-1,3-dimethyl uracil; D003374:Coumarins; D006571:Heterocyclic Compounds; D011744:Pyrimidinones; D013438:Sulfhydryl Compounds; D014498:Uracil