Crystal structures of three newly synthesized flavanone hydrazones

The crystal structures of racemic mixtures of three new flavanone-hydrazones in the centrosymmetric space group (P [Image: see text] ), are reported. The structures of (±,E)-N′-[5,7-dihy­droxy-2-(4-hy­droxy­phen­yl)chroman-4-yl­idene]-2-(naphthalen-1-yl)acetohydrazide ethyl acetate monosolvate, C(27)H(22)N(2)O(5)·C(4)H(8)O(2), and of (±,E)-N′-[5,7-dihy­droxy-2-(4-hy­droxy­phen­yl)chroman-4-yl­idene]-4-hy­droxy­benzo­hydra­zide ethanol monosolvate, C(22)H(18)N(2)O(6)·C(2)H(5)OH, both exhibit an intra­molecular O—H⋯N and multiple inter­molecular O—H⋯O and C—H⋯O-type hydro­gen bonds. The third structure, that of (±,E)-N′-(6-methoxy-2-phenyl­chroman-4-yl­idene)-2-(naphthalen-1-yl­oxy)acetohydrazide, C(28)H(24)N(2)O(4), has only one inter­molecular N—H⋯O-type hydrogen bond. In each of the three cases, the crystal packings are stabilized by π–π stacking inter­actions between various aromatic components of symmetry-related mol­ecules. The chiral carbon atom of the substituted chromane ring system in each case is puckered away from rest of the ring system.