Synergy of Solid-State NMR, Single-Crystal X-ray Diffraction, and Crystal Structure Prediction Methods: A Case Study of Teriflunomide (TFM).

ABSTRACT: In this work, for the first time, we present the X-ray diffraction crystal structure and spectral properties of a new, room-temperature polymorph of teriflunomide (TFM), CSD code 1969989. As revealed by DSC, the low-temperature TFM polymorph recently reported by Gunnam et al. undergoes a reversible thermal transition at -40 °C. This reversible process is related to a change in Z' value, from 2 to 1, as observed by variable-temperature ¹H-¹³C cross-polarization (CP) magic-angle spinning (MAS) solid-state NMR, while the crystallographic system is preserved (triclinic). Two-dimensional ¹³C-¹H and ¹H-¹H double-quantum MAS NMR spectra are consistent with the new room-temperature structure, including comparison with GIPAW (

SUBMITTER: Pawlak T 

PROVIDER: S-EPMC8273857 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature