Studies On The Synthesis Of Pyrazoles And Diazpines As Medical Intermediates

Pyrazoles and diazepines are important heterocyclic compounds bearing physiological and biological activities. They are often used for the syntheses of medicines, pesticides, dyestuffs and so on. On the other hand, enamiones are active synthetic intermediates and widely used for the syntheses of heterocyclic compounds such as pyrimidine, pyridazine, isoxazole, pyrazole, etc. In this thesis, the investigation was concentrated on the synthesis of pyrazoles and diazepines from enamiones. Using our efficient method, some new pyrazoles and diazepines were successfully synthesized with enamiones as the starting materials.This thesis mainly includes three aspects:1. Described the current developments of pharmaceutical intermediates. Thensummarized the progress in the application of pyrazoles and their syntheticmethodologies. And reviewed the syntheses, biological activities of diazepines, andtheir applications in the pharmaceutical synthesis.2. From the reaction of acetyl substituted aromatic or nitrogen heterocyclic compoudswith DMFDMA(also used as the solvent), afforded the corresponding 1-azo or1-aryl-enamiones. A series of new pyrazoles were obtained via the reaction ofsynthesized 1-azo or 1-aryl-enamiones with hydrazine hydrate. The optimal reactioncondition was invetigated from the variation in the substitutes, reaction temperature,inventory ratio etc. Under the optimal reactions, fourteen new 5-azo or5-aryl-1H-pyrazoles were obtained.3. Seven 5-azo or 5-aryl-2,3-dihydro-1H-[1,4]diazpine compounds were obtained viaMichael-condensation and dehydrative cyclization reaction from synthesized 1-azoor 1-aryl-enamione with ethylenediamine. Four of them are new compounds.Therefore, in this thesis, fourteen enamiones and twenty-one new pyrazoles and diazepines were synthesized in high yields from easily available materials under mild conditions. All the compounds have been verified by 1H NMR spectra, IR, HPLC and melting point.