Chem. J. Chinese Universities ›› 2024, Vol. 45 ›› Issue (1): 20230400.doi: 10.7503/cjcu20230400

• Organic Chemistry • Previous Articles     Next Articles

Study on the Polymorphism of Linagliptin

LIU Qi1, LIU Moyi2, DONG Siyu3, WANG Xuezhong1, HE Yunliang1()   

  1. 1.Beijing Key Laboratory of Enze Biomass Fine Chemicals,College of New Materials and Chemical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China
    2.China Resources Double?crane Pharmaceutical Co. ,Ltd. ,Beijing 100124,China
    3.College of Information Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China
  • Received:2023-09-07 Online:2024-01-10 Published:2023-11-10
  • Contact: HE Yunliang E-mail:heyunliang@bipt.edu.cn

Abstract:

In this paper, the complicated polymorphism of linagliptin was investigated along with conformational changes in the lattice. Three crystal structures including form A were obtained for the first time by the growth of single crystals and X-ray single-crystal diffraction analysis. The structure and molecular conformation of each crystal were analyzed in combination with two crystal structures reported in the literature. Two crystal forms, form A and form F, are found among the five crystals. Form F can exist as a variety of channel solvates, with lattice parameters varying slightly with the included solvent. There is a high energy barrier between the conformers in form A lattice and those in form F, which probably accounts for the difficult conversion from form F to form A. The molecular conformations are not identical in the varieties of form F, and their powder X-ray raditional diffraction(PXRD) patterns are also distinctly different. Finally, the conversion between form A and form F was revealed by common methods, such as suspension conversion and thermal analysis.

Key words: Linagliptin, Polymorphism, Conformer, Channel solvate

CLC Number: 

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