Resolution Study Of Racemic Mandelic Acid With D-Pseudoephedrine

Objective:1 To resolve racemic mandelic acid With d-Pseudoephedrine as resolution agent and establish the technological process to suit the industrial production . 2 To recover d-pseudoephedrine so that made utilization of resolution agent. 3 To provide a new resolution agent of: optically pure mandelic acid. Methods: 1 Mixed d-pseudoephedrine and dl-mandelic acid in unhydrated alcohol ,add saturated Ca2+ solution, separate the precipitate and liquor ,get the d-and l-mandelic acid. 2 Adjusted the pseudoephedrine hydrochloride solution with NaOH to alkalinity,get the pseudoephedrine. Results: 1 For The d-mandelic acid,general yield is 91.1%,the optical purity(%ee) is 98.7%; for the l-mandelic acid,the optical purity is 85.1% and general yield is 91.1%。2 The recycle rate of pseudoephedrine is 85.5%. Conclusion: 1 Resolve the technical difficulties of pseudoephedrine as the resolution reagent to separate racemic mandelic acid; 2 The technological process conform to the request of resolution and broaden the scope of the application of pseudoephedrine. 3 Recycling the Pseudoephedrine is successful,utilization of Pseudoephedrine as resolution agent further;4 Get a new resolution agent: optically pure mandelic acid; 5 Find a new application in the chemical field of pseudoephedrine .