154698-00-7

Upstream product

• 174748-63-1 2,3-dimethyl-3H-5,7-dihdyrothieno<3,4-d>pyrimidin-4-one 
• 5719-23-3 2-methyl-3H-5,7-dihydrothieno<3,4-d>pyrimidin-4-one 
• 941-69-5 N-phenyl-maleimide 
• 174748-62-0 2,3-dimethyl-3H-5,7-dihydrothieno<3,4-d>pyrimidin-4-one 6,6-dioxide 
• 2689-68-1 methyl 4-oxotetrahydrothiophene-3-carboxylate 

Relevant academic research and scientific papers

Generation and trapping of 5,6-dimethylenepyrimidin-4-ones in Diels-Alder and Michael additions

Pyrimidone fused sulfones 5-7 were obtained from the reaction of amidines with 3-methoxycarbonyl-4-oxotetrahydrothiophene followed by N-methylation and oxidation with mCPBA. On heating in solution at 150°C, extrusion of SO2 occurred to give the highly reactive 5,6-dimethylenepyrimidin-4-ones which were intercepted in situ in Diels-Alder reactions to give the adducts 24-28 and in conjugate addition reactions with thiol nucleophiles to give the thioethers 29 and 30.

Pyrimidine o-quinodimethanes: Formation of 1:1 and 2:1 adducts with dienophiles

Pyrimidine fused dihydrothiophene S,S-dioxides 7 undergo thermal elimination of sulfur dioxide to give the pyrimidine o-quinodimethanes 8 which can be intercepted in Diels-Alder reactions to give substituted 5,6,7,8-tetrahydroquinazolines; these form cyclooctapyrimidines on heating with more dienophile.