Chemical Resolution Of Pantolactone

Vitamin B5 plays a very important role in maintaining human health,and it also has good economic benefits for poultry bre.e.ding.The synthesis of vitamin B5 is mainly limited by the preparation of key intermediate material D-pantolactone.Due to the high price of the resolving agent,the chemical splitting method for synthesizing D-pantolactone has little competitive advantage in industrial production.Chemical decomposition of pantolactone is carried out using a relatively inexpensive chiral resolving agent chiral ?-phenethylamine.The synthesis of R-(+)-?-phenylethylamine hydrochloride and DL-pantoic acid sodium salt was carried out to perform the R-(+)-?-phenylethylamine-DL-pantoic acid salt diastereomer salt.A method for monitoring the purity of a single double salt was established,and the correlation between different single solvents and binary mixed solvents on the separation of diastereomeric salts was studied.It was found that the mixed solvent was ethyl acetate to ethanol in a volume ratio of 1 : 1,when the material-liquid ratio(diastereomeric salt: solvent)is 2g: 3m L,the effect of filtering and separating the diastereomeric salt is best after stirring at 20 ?-30 ? for 8h.By adopting the strategy of alkaline decomposition of double salt,first recovering the resolving agent and then acidifying it to prepare D-pantoic acid lactone,recovering the resolving agent R(+)-?-phenylethylamine,and obtaining high optically active D-pan Lactone(HPLC ee 97.23%).R-(+)-?-phenethylamine—D-pantoate and R-(+)-?-phenethylamine—L-pantoate were separately prepared,and two kinds of singles were obtained by single crystal culture.Crystal,and the crystal structure is determined by X-ray single crystal diffraction,and the diastereomeric salt formed by the resolution of R-(+)-?-phenethylamine to resolve the pantolactone is explained from the thre.e.-dimensional accumulation of crystals.The reason for the difference in solvent.