Synthesis Of Heterocyclic Compounds Containing Nitrogen From D-Glucose And Research On The New Methodology Of Pyridine Compounds

The thesis consists of two main sections. The synthesis of 1,3,4-thiadiazoles,triazolotriazines and dioxapyrrolinopyrazoles containing chiral pyrazolyl moietyfrom D-glucose is described in the first part and the section one is about theDiels-Alder reactions between dienophile enaminones and diene 1,2,4-triazines,which provides a new methodology to construct the pyridine compounds. A total of37 new compounds were synthesized. The structures of all the synthesizedcompounds were characterized by IR, ¹H NMR and elemental analysis, somerepresentative ones were further confirmed by ¹³C NMR, HMQC, HMBC and MS. Inaddition, one target compound was selected for X-ray crystal diffraction to determinetheir accurate spatial structures. The synthetic methodologies were also discussed.In the first chapter, two reviews on the synthesis of nitrogen compounds fromcarbohydrates and the synthesis of pyridines by Diels-Alder reaction were introducedrespectively.In the second and the third chapters, the synthesis of new heterocycliccompounds bearing chiral pyrazolyl moiety from D-glucose was introduced. In thesecond chapter, eleven 1,3,4-oxadizoles bearing chiral pyrazolyl moieties(4a-k) andfive triazolotriazines bearing chiral pyrazolyl moieties(5a-e) were obtained from5-[(1'S)-1',2'-diacetyl-oxyethyl]-1-phenylpyrazol-3-carboxaldehyde(1) with arylcar-bohydrazide or (5-aryl-1,2,4-triazin-3-yl)hydrazine through an intramolecular1,3-dipolar cycloaddition in the presence of the non-metal oxidant IBD. The merit ofthis process was its efficiency, simplification of synthetic steps and omission of purification of intermediates. In the third chapter, the synthesis of5-[(1'S)-1',2'-diacetyl-oxyethyl]-1-phenylpyrazol-3-carboxaldehyde oxime(2) from5-[(1'S)-1',2'-diacetyl-oxyethyl]-1-phenylpyrazol-3-carboxaldehyde(1) and phenyl-hydrazine were introduced firstly. The synthesis of nine dioxapyrrolino[3,4-c]pyrazoles containing chiral pyrazolyl moiety(6a-i) from 2 with N-substituted-phenylmaleimide by nonmetal oxidant IBD-initiated intermolecular 1,3-dipolarcycloaddition was described in detail. The differences among solid-phase, liquidphase, the conventional heating and microwave heating were examined respectively,and the results turned out to be that it was more preferred when the reactions werecarried out using silica gel-IBD under solvent-free conditions and microwaveirradiation. Meanwhile, the reaction mechanism was discussed.In the fourth chapter, 5-phenyl-1,2,4-triazine(3) was synthesized from(5-phenyl-1,2,4-trizin-3-yl)hydrazine in the presence of sodium ethoxide firstly. Themerit of this process was simplification of operation and good yield (more than 90%),which to our knowledge has not been reported so far in literature. Then the firstapplication of enaminone as dienophile with 1,2,4-triazines in Diels-Alder reactionwas described. It proved to be an unexpected methodology to construct pyridines.Meanwhile, the effects of different reaction conditions on the reaction wereinvestigated and the reaction mechanism was discussed. The accurate spatial structureof compounds (7'b) was can determinated by X-ray crystal diffraction conveniently,which provided firm base for the study of reaction mechanism.