N-(2-Fluoro­phen­yl)-2,6-dimethyl-1,3-dioxan-4-amine

In the title compound, C₁₂H₁₆FNO₃, the dioxane ring adopts a chair conformation with the methyl groups and amine N atom in equatorial positions. The best plane through the dioxane ring makes a dihedral angle of 43.16 (8)° with the phenyl ring. In the crystal, pairs of C—H...O hydrogen bonds link the mol­ecules into centrosymmetric R₂²(8) dimers, which are linked into [100] chains by further C—H...O hydrogen bonds. The N—H group does not participate in hydrogen bonding.

2,6-Dimethyl-N-(2-methyl­phen­yl)-1,3-dioxan-4-amine

In the title compound, C₁₃H₁₉NO₂, the dioxane ring adopts a chair conformation and its mean plane makes a dihedral angle of 45.36 (8)° with the phenyl ring. In the crystal, mol­ecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with R²₂(12) ring motifs. These dimers are consolidated by pairs of C—H...O hydrogen bonds with R²₂(8) ring motifs.

N-(4-Bromo­phen­yl)-2,6-dimethyl-1,3-dioxan-4-amine

In the title compound, C₁₂H₁₆BrNO₂, the dioxane ring adopts a chair conformation and its mean plane makes a dihedral angle of 60.63 (12)° with the 4-bromo­phenyl ring. In the crystal, mol­ecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with an R₂²(8) ring motif. These dimers are consolidated by pairs of C—H...O hydrogen bonds with an R₂²(16) ring motif. Adjacent dimers are connected via C—H...O hydrogen bonds, forming infinite chains propagating along the c-axis direction.