Radical Addition of Hydrazones by α-Bromo Ketones To Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis was written by Fan, Xiu-Wei;Lei, Tao;Zhou, Chao;Meng, Qing-Yuan;Chen, Bin;Tung, Chen-Ho;Wu, Li-Zhu. And the article was included in Journal of Organic Chemistry in 2016.Synthetic Route of C18H16N2O2 The following contents are mentioned in the article:
A novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramol. cyclization affords the important pyrazole skeleton in good to excellent yields. This efficient strategy under mild conditions with wide group tolerance provides a potential approach to the 1,3,5-trisubstituted pyrazoles. This study involved multiple reactions and reactants, such as Ethyl 1,5-diphenyl-1H-pyrazole-3-carboxylate (cas: 17355-75-8Synthetic Route of C18H16N2O2).
Ethyl 1,5-diphenyl-1H-pyrazole-3-carboxylate (cas: 17355-75-8) belongs to pyrazole derivatives. The 1H-pyrazole provides an excellent means by which to provide the requisite hydrogen bond acceptor–donor motifs, whether as a monocyclic ring or as a fused indazole ring. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Synthetic Route of C18H16N2O2
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics