139124-96-2Relevant academic research and scientific papers
Heterocyclic fused 2,5-dihydrothiophene S,S-dioxides as precursors to heterocyclic o-quinodimethanes
Chaloner,Crew,O'Neill,Storr,Yelland
, p. 8101 - 8116 (2007/10/02)
2,5-Dihydrothiophene 5,5-dioxides 8 and 6 have been obtained by interception of flash-pyrolytically produced 2,3-dihydro-2,3-bis(methylene)thiophene with sulfur dioxide and from methyl 4,5-bischloromethylthiophene-2-carboxylate from 3-phenylsulfonyl-2,5-dihydrothiophene S,S-dioxide by cycloaddition of diazomethane, base induced aromatisation and N-substitution of the sulfone 14. Reaction of 3-acetyl-4-phenylthio-2,5-dihydrothiophene S,S-dioxide with hydrazine and interception of 1-methyl-4,5-dihydrobis(methylene)pyrazole also gave pyrazole fused sulfones. On heating at 200°C, the heterocyclic fused sulfones underwent extrusion of sulfur dioxide and the resulting heterocyclic o-quinodimethanes were trapped with a range of dienophiles.
A new route to heterocyclic fused 2,5-dihydrothiophene S,S-dioxides: Formation of pyrazole analogues of o-xylylenes
Chaloner, Lynne M.,Crew, Andrew P. A.,Storr, Richard C.,Yelland, Michael
, p. 7609 - 7612 (2007/10/02)
Addition of diazomethane to 3-phenylsulphonyl-2,5-dihydrothiophene S,S-dioxide 3, followed by base induced aromatisation gives the sulphone 7, a precursor to pyrazole analogues of o-quinodimethane).
