Design of new anti-Alzheimer drugs: ring-expansion synthesis and synchrotron X-ray diffraction study of dimethyl 4-ethyl-11-fluoro-1,4,5,6,7,8-hexahydroazonino[5,6-<i>b</i>]indole-2,3-dicarboxylate
Acta crystallographica. Section E, Crystallographic communications