2-[(Cyclohex-3-en-1-ylmethoxy)methyl]-6-phenyl-1,2,4-triazine-3,5(2H,4H)-dione

In the title 1,2,4-triazine derivative, C17H19N3O3, the heterocyclic ring is planar (r.m.s. deviation = 0.040 Å) and effectively coplanar with the adjacent phenyl ring [dihedral angle = 4.5 (2)°] but almost perpendicular to the (cyclohex-3-en-1-ylmethoxy)methyl residue [N—N—C—O torsion angle = 71.6 (5)°], so that the molecule has an ‘L’ shape. Supramolecular chains along [001] are formed in the crystal via N—H⋯O hydrogen bonds where the acceptor O atom is the ether O atom. The adjacent carbonyl O atom forms a complementary C—H⋯O contact resulting in the formation of a seven-membered {⋯HNCO⋯HCO} heterosynthon; the second carbonyl O atom forms an intramolecular C—H⋯O contact. Chains are connected into a supramolecular layer in the ac plane by π–π interactions [ring centroid–centroid distance = 3.488 (3) Å]. The central atom in the –CH2CH2C(H)= residue of the cyclohexene ring is disordered over two sites, with the major component having a site-occupancy factor of 0.51 (2).

In the title 1,2,4-triazine derivative, C 17 H 19 N 3 O 3 , the heterocyclic ring is planar (r.m.s. deviation = 0.040 Å ) and effectively coplanar with the adjacent phenyl ring [dihedral angle = 4.5 (2) ] but almost perpendicular to the (cyclohex-3-en-1ylmethoxy)methyl residue [N-N-C-O torsion angle = 71.6 (5) ], so that the molecule has an 'L' shape. Supramolecular chains along [001] are formed in the crystal via N-HÁ Á ÁO hydrogen bonds where the acceptor O atom is the ether O atom. The adjacent carbonyl O atom forms a complementary C-HÁ Á ÁO contact resulting in the formation of a seven-membered {Á Á ÁHNCOÁ Á ÁHCO} heterosynthon; the second carbonyl O atom forms an intramolecular C-HÁ Á ÁO contact. Chains are connected into a supramolecular layer in the ac plane byinteractions [ring centroid-centroid distance = 3.488 (3) Å ]. The central atom in the -CH 2 CH 2 C(H) residue of the cyclohexene ring is disordered over two sites, with the major component having a siteoccupancy factor of 0.51 (2).
The reaction was quenched by addition of sat. aq. NaHCO 3 solution (5 ml). The mixture was evaporated under reduced pressure and the residue was extracted with ether (3 x 50 ml). The combined ether fractions were collected, dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified on a silica gel column using 1:5 petroleum ether / chloroform to give the title compound in 64% (0.199 g) yield. Colourless crystals were obtained upon crystallization from its ethanol solution (El-Brollosy, 2008  included in the refinement in the riding model approximation. The amino H-atom was refined freely. In the absence of significant anomalous scattering effects, 799 Friedel pairs were averaged in the final refinement. The C16 atom of the cyclohexene ring was disordered over two positions. From anisotropic refinement, the major component of the disorder had a site occupancy factor = 0.51 (2). The pairs of the respective C15-C16/C16′-C17 bond lengths were restrained to be within 0.01 Å of each other; the anisotropic displacement parameters for the disordered atoms were constrained to be equal.

Figure 1
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level. Only the major component of the disordered C16 atom is shown.    A view in projection down the a axis of the unit-cell contents for (I). The N-H···O and π-π interactions are shown as blue and purple dashed lines, respectively. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.002 Δρ max = 0.24 e Å −3 Δρ min = −0.30 e Å −3

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. 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 Occ. (