A simple and catalyst free one pot access to the pyrazolone fused 2,8-dioxabicyclo[3.3.1]nonanes was written by Bingi, Chiranjeevi;Emmadi, Narender Reddy;Chennapuram, Madhu;Nanubolu, Jagadeesh Babu;Atmakur, Krishnaiah. And the article was included in RSC Advances in 2014.Reference of 401-73-0 This article mentions the following:
A series of novel aryl and heteroaryl fused 2,8-dioxabicyclo[3.3.1]nonanes I (R = 4-Cl, 4-MeO, 4-Br, etc.; R1 = C6H5, 2-BrC6H4, 4-CNC6H4, etc.; R2 = H, Ph) was accomplished by one pot, catalyst free reaction of 2-hydroxy chalcones with 3-trifluoromethyl substituted pyrazolones in xylene at reflux temperature The role of the trifluoromethyl functional group in formation of I was confirmed by comparative studies with 3-Me substituted pyrazolones and the outcome is presented. In the experiment, the researchers used many compounds, for example, 3-(Trifluoromethyl)-1H-pyrazol-5(4H)-one (cas: 401-73-0Reference of 401-73-0).
3-(Trifluoromethyl)-1H-pyrazol-5(4H)-one (cas: 401-73-0) belongs to pyrazole derivatives. The strategies for the synthesis of pyrazoles generally can be applied for the construction of indazoles. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Reference of 401-73-0
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics