Synthesis, Crystal Properties Investigation Of Rosolic Acid And The Study Of Its Esterificable Reaction

A new method for synthesis of rosolic acid is introduced in this thesis: under solvent-free conditions, grinding the mixture containing phenol, oxalic acid and copper salt catalyst and then irradiated by MW to produce rosolic acid. The rough catalytic product is separated and finally characterized by determinations of IR, ¹H-NMR, UV-Vis, element analysis and m.p. By an UV-Vis quantitative analysis method based on the absorption of rosolic acid, the best synthetic conditions are selected. Meanwhile, a possible catalytic mechanism is proposed, and furthermore, an esterification of rosolic acid with acetic acid is carried out to synthesize an tri(4-acetoxy)phenylmethane. This thesis is divided into 5 chapters.In chapter 1, the microwave application in the life is introduced, particularly its development as a new research area in the chemical synthesis is discussed. Finally, the signification of this work is also described.In chapter 2, rosolic acid is catalytically prepared under solvent-free condition by microwave irradiation after grinding the mixture containing phenol, oxalic acid and copper salt catalyst. The product is characterized by means of UV-Vis, IR, ¹H-NMR and CCD methods. Its related research about the property as an acid base titration indicator is discovered, and its special electricity chemistry property is carried out by cyclic voltammetry. The reaction conditions are optimized for getting high yield of rosolic acid.In chapter 3, by tracking the XRD variety of CuCl₂ catalyst, a series of intermediates during this process are observed. A possible mechanism of this new method synthesizing the rosolic acid is proposed based on the in situ XRD determinations.In chapter 4, an ultraviolet-visible absorption spectroscopy way is employed to optimize the reaction conditions of this new reaction. By change of the catalyst category, the ratio of reagents, the grinding time, the microwave action time and the microwave strength etc. to examine their influences on the yield of rosolic acid, the best conditions are concluded as: (1) the best catalyst: CuCl₂; (2) the best ratio of reagents is phenol: oxalic acid: copper salt catalyst=1:1:0.1; (3) the best grinding time is 10 min; and (4) the best microwave action time is 6 min with mild-strong level (about 700 W). The best yeild of rosolic acid can reach 41% under the optimized conditions.In chapter 5, the synthesized rosolic acid is applied as one of the reagents to compose a derivative. Rosolic acid reacts with acetic anhydride to synthesize rosolic acid-triacelate ester [tri (4-acetoxy) phenylmethane] under reflux condition. Influences of the reaction time, the reactant proportion, and as well as the catalyst percentage on the reaction was discussed in detail.In chapter 6, Rosolic molecule represent two different figures in acid and alkali solution, the crystal picture are showed and discussed, they are connected by O-H…O hydrogen bonds [O…O=2.662 (2) and 2.648 (2) A] into two dimensional square networks that are twofold interpenetrated.