Preparation Of Tartaric Acid Derived Chiral Stationary Phase And Chromatographic Applications

Tartaric acid is a natural chiral compound with two carboxylic acid and two hydroxyl groups of the symmetrical structure. Tartaric acid and its derivatives as chiral reagents for the separation of basic enantiomers have a good effect. Because of its wide variety of sources and low price, it has used greatly in the pharmaceutical industry. Based on its great chiral separation ability, if tartaric acid and its derivatives could be bonded to silica gel by some way, those stationary phases will have a good application potential in chiral separation. In recent years, new organic synthetic methods "click chemistry" has been greatly used in the preparation process of chiral stationary phases. Because of its high efficiency and specificity, introducing this method in the preparation of CSP could make the target functional molecules bond to silica easily.In this thesis, according to the characteristics of tartaric acid, the previous chiral stationary phases and chromatographic properties, a series of derivatives of tartaric acid in which hydroxyl groups was protected by different aryl chloride and alkynyl groups was introduced, hoping to use click chemistry reaction with the azide group successfully prepared stationary phase. In the preparation process, two synthetic strategies were applied, one is use click chemistry to make y-azido-propyl triethoxysilane react with alkynyl-tartaric acid derivatives under the liquid-liquid conditions and pure chiral silica precursor was then got, one-step bonding to the silica surface was utilized during this method; the other is bond y-azido-propyl triethoxypropionic silane onto silica first, and then react with tartaric acid derivatives containing alkynyl group under solid-liquid conditions. By elemental analysis and infrared spectroscopy we can evaluate the advantages and disadvantages of both methods. In this paper, we obtained several different stationary phases and evaluated the chromatographic performance under NP and RP modes.From the results, the first strategy by getting the exact structure of the chiral silica precursor and one-step method bonded to the silica gel has larger amount of chiral selectors bonded and is a stable and reliable preparation method. However, the classic click chemistry under solid-liquid condition has not achieved completely conversion of azide-group on silica, and its further optimization of reaction conditions should be done. From the point of view of chromatographic evaluation, a system of several tartaric acid derived chiral stationary phases showed a certain degree of chiral recognition ability, two types chiral stationary phases derived with 3,5-dimethyl-benzoyl and 3,5-dinitrobenzoyl have better separation ability, and different resolution results for same analytes between the two CSPs were observed.