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

In the title compound, C12H16FNO2, the dioxane ring adopts a chair conformation with the methyl substituents and the C—N bond in equatorial orientations. Its mean plane subtends a dihedral angle of 40.17 (6)° with the benzene ring. In the crystal, weak N—H⋯F hydrogen bonds link the molecules into C(7) chains propagating in [100].

In the title compound, C 12 H 16 FNO 2 , the dioxane ring adopts a chair conformation with the methyl substituents and the C-N bond in equatorial orientations. Its mean plane subtends a dihedral angle of 40.17 (6) with the benzene ring. In the crystal, weak N-HÁ Á ÁF hydrogen bonds link the molecules into C(7) chains propagating in [100].

Comment
As part of our ongoing studies of dioxane derivatives with possible biological activity (Fatima et al., 2013), we now describe the single-crystal structure determination of the title compound.

Experimental
To 4-Fluoroaniline (1 mmol), Acetaldehyde (3 mmol) was added dropwise and stirred for about 4 h at 0 °C. The progress of the reaction was monitored through TLC. The reaction mixture was washed with petroleum ether. Resultant was dissolved in diethylether and allowed to evaporate. Solid product obtained was recrystallized with diethylether.

Refinement
The hydrogen atoms were placed in calculated positions with C-H = 0.93 Å to 0.98 Å refined in the riding model with fixed isotropic displacement parameters:U iso (H) = 1.5U eq (C) for methyl group and U iso (H) = 1.2U eq (C) for other groups.

Figure 2
The crystal packing of the title compound viewed down a axis. H-atoms not involved in H-bonds have been excluded for clarity.

N-(4-Fluorophenyl)-2,6-dimethyl-1,3-dioxan-4-amine
Crystal data An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq O1 0.85420 (