154697-87-7

Upstream product

• 5719-23-3 2-methyl-3H-5,7-dihydrothieno<3,4-d>pyrimidin-4-one 
• 5719-46-0 4-chloro-2-methyl-5,7-dihydrothieno<3,4-d>pyrimidine 
• 108-98-5 thiophenol 
• 154697-84-4 4-chloro-2-methyl-5,7-dihydrothieno<3,4-d>pyrimidine 6,6-dioxide 
• 930-69-8 sodium thiophenolate 

Relevant academic research and scientific papers

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.

Pyrimidine ortho-quinodimethanes

The pyrimidine sulfones 10, R = Me; Nu = OMe, NEt2, SPh, H and 11, R = Ph; Nu = OMe were synthesised from the dihydrothienopyrimidones 7, R = Me, Ph by conversion to the chloro derivatives 8 followed by oxidation with mCPBA and reaction with the appropriate nucleophile or hydrogen and Pd. Heating of the sulfones in 1,2,4-trichlorobenzene gave the pyrimidine o-quinodimethanes which were intercepted in Diels-Alder reactions to give tetrahydroquinazolines.