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 R 2 2(12) ring motifs. These dimers are consolidated by pairs of C—H⋯O hydrogen bonds with R 2 2(8) ring motifs.

In the title compound, C 13 H 19 NO 2 , 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-HÁ Á ÁO hydrogen bonds, forming inversion dimers with R 2 2 (12) ring motifs. These dimers are consolidated by pairs of C-HÁ Á ÁO hydrogen bonds with R 2 2 (8) ring motifs.
In the crystal, molecules are linked by a pair of N-H···O hydrogen bonds forming inversion dimers with an R 2 2 (12) ring motif (Bernstein et al., 1995). These dimers are consolidated by a pair of C-H···O hydrogen bonds with an R 2 2 (8) ring motif (Table 1 and Fig. 2).

Experimental
To 2-toulidine (1 mmol), acetaldehyde (3 mmol) was added drop wise and the mixture was stirred for ca. 4 h at 273 K.
The progress of the reaction was monitored through TLC. On completion the reaction the mixture was washed with petroleum ether. The resultant mixture was dissolved in diethylether and the solvent allowed to evaporate. The solid product obtained was recrystallized with diethylether to yield block-like colourless crystals, suitable for X-ray diffraction analysis.

Refinement
The NH H atom was located in a difference Fourier map and freely refined. The C bound H atoms were placed in calculated positions and refined as riding atoms: C-H = 0.93 -0.98 Å with U iso (H) = 1.5U eq (C-methyl) and = 1.2U eq (C) for other H atoms.

Figure 2
A view along the b axis of the crystal packing of the title compound. The N-H···O and C-H···O hydrogen bonds are shown as dashed lines (see Table 1 for details; H atoms not involved in hydrogen bonding have been omitted for clarity). Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.