Thermal behaviour,phase diagram,and spectroscopic properties of rac-indobufen and its enantiomers

The binary phase diagram of the enantiomers of indobufen, 1 (Ibustrin), an antithrombotic drug, has been investigated by differential scanning calorimetry (DSC); 1 is a racemic compound (racemate) with melting point lower than that of the enantiomers. Its thermal behaviour (DSC) has been examined and is discussed in comparison with other physical methods (IR spectroscopy and X-ray powder diffraction). Absolute configuration has been assigned to the enantiomers by ¹H-NMR correlations. © 1995 Wiley-Liss, Inc.