Crystal structures of two 4H-chromene derivatives: 2-amino-3-cyano-4-(3,4-di­chloro­phen­yl)-7-hy­dr­oxy-4H-benzo[1,2-b]pyran 1,4-dioxane monosolvate and 2-amino-3-cyano-4-(2,6-di­chloro­phen­yl)-7-hy­dr­oxy-4H-benzo[1,2-b]pyran

In the title compounds, C16H9Cl2N2O2C4H8O2 and C16H9Cl2N2O2, the bicyclic 4H-chromene cores are nearly planar with maximum deviations of 0.081 (2) and 0.087 (2) A˚ . In both structures, the chromene derivative molecules are linked into centrosymmetric dimers by pairs of N—HO hydrogen bonds, forming R2 2(16) motifs. These dimers are further linked in the 3,4-dichlorophenyl derivative by N—HN hydrogen bonds into double layers parallel to (100) and in the 2,6-dichlorophenyl derivative by O—HN hydrogen bonds into ribbons along the [110] direction. In the 3,4-dichlorophenyl derivative, the 1,4-dioxane solvent molecules are connected to the chromene molecules via O—HO hydrogen bonds