Efficient Synthesis of Fully Substituted and Diversely Functionalized Pyrazoles through <i>p</i>‐TSA Catalyzed One‐Pot Condensation of Cyclic <i>β</i>‐Diketones, Arylglyoxals and Arylhydrazones
作者:Arun Dhurey、Subhro Mandal、Animesh Pramanik
DOI:10.1002/ejoc.202300770
日期:2023.10.21
An acid catalyzed one-pot condensation of readily available cyclic β-diketones, arylglyoxals and arylhydrazones produces a library of diverselyfunctionalized pyrazole derivatives in excellent yield under metal-catalyst-free benign conditions.
Photolytic cleavage of the nitrogen-nitrogen single bond in benzaldehyde phenylhydrazones produced aminyl (R2N) and iminyl (R2C=N) radicals. This photochemical property was utilized in the development of hydrazones as photo-induced DNA-cleaving agents. Irradiation with 350 nm UV light of arylhydrazones bearing substituents of various types in a phosphate buffer solution containing the supercoiled circular phiX174 RFI DNA at pH 6.0 resulted in single-strand cleavage of DNA. Attachment of the electron-donating OMe group to arylhydrazones increased their DNA-cleaving activity. Results from systematic studies indicate that both the aminyl and the iminyl radicals possessed DNA-cleaving ability. (C) 2004 Elsevier Ltd. All rights reserved.
ARAKI, SHUKI;AOYAMA, NAOMITSU;BUTSUGAN, YASUO, BULL. CHEM. SOC. JAP., 62,(1989) N, C. 1612-1620