Studies About The Reactions Of N-tosylhydrazones And Its Applications In The Synthesis Of Pyrazoles And Indazole-drugs

The paper mainly introduces the tosylhydrazones in chemical reaction and its application in pyrazole and indazole drugs synthesis.The paper was divided into three parts.The first part introduced an efficient N-alkylation reaction of tosylhydrazones in the presence of triphenylphosphine;triphenylphosphine played a key role in the transformation.A range of N-alkylated tosylhydrazones were prepared in good to high yields.The second part is about regioselective synthesis of 1,3,5-trisubstituted pyrazoles from N-alkylated tosylhydrazones and terminal alkynes.An efficient synthesis of 1,3,5-trisubstituted pyrazoles from N-alkylated tosylhydrazones and terminal alkynes was developed.The protocol was applied to a wide range of substrates and demonstrated excellent tolerance to a variety of substituents,including both electron-donating and-withdrawing groups.The thirdly part introduced a Cu2O-promoted the reactions of o-haloaryl N-tosylhydrazones to synthesize indazoles and made a brief overview about indazole chemistry.A simple and efficient synthesis of indazoles from readily accessible E/Z mixtures of o-haloaryl N-tosylhydrazones has been developed.A series of valuable products were prepared in good yields and the method has been successfully applied to the synthesis of bioactive compounds YC-1 and its analogues.