Figure 4. Crystal conformers of N -[ (1S) -1-phenylethyl]-amide 3a and racemate 5a (according to the Figure 4. Crystal conformers of N -[ (1S) -1-phenylethyl]-amide 3a and racemate 5a (according to the data of X-ray diffraction analysis), and N -[ (1R) -1-phenylethyl]-amide 4a (presumably). The benzothiazine fragment