Dimethyl 4-(3-hydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

The 1,4-dihydropyridine ring in the title compound, C17H19NO5, has a flattened-boat conformation, and the benzene ring is almost orthogonal to it [dihedral angle = 82.98 (12)°]. The hydroxy group is disordered over two positions in a 0.780 (4):0.220 (4) ratio. In the crystal, hydrogen-bonding interactions of the type Na—H⋯Oc and Oh—H⋯Oc (a = amine, c = carbonyl and h = hydroxy) link the molecules into a three-dimensional network.

The 1,4-dihydropyridine ring in the title compound, C 17 H 19 NO 5 , has a flattened-boat conformation, and the benzene ring is almost orthogonal to it [dihedral angle = 82.98 (12) ]. The hydroxy group is disordered over two positions in a 0.780 (4):0.220 (4) ratio. In the crystal, hydrogen-bonding interactions of the type N a -HÁ Á ÁO c and O h -HÁ Á ÁO c (a = amine, c = carbonyl and h = hydroxy) link the molecules into a three-dimensional network.
is orthogonal to the 1,4-dihydropyridine ring, with the dihedral angle between their respective least-squares planes being 82.98 (12) °.
The crystal structure features significant hydrogen bonding interactions, Table 1. The N amine -H···O carbonyl interactions lead to chains with glide symmetry along the c axis. O hydroxyl -H···O carbonyl hydrogen bonds exist normal to the chain resulting in a three-dimensional network, Fig. 2. As noted in the Experimental, the hydroxyl group is disordered over two positions so that the above description pertains to the major component of the structure only. The minor component of the disorder allows for the formation of O hydroxy -H···O hydroxy hydrogen bonds, Table 1, to provide addiotnal cohesion to the crystal packing.
The remaining H were located from a difference map and refined with O-H = 0.82±0.01 and N-H = 0.86±0.01, and with U iso (H) = nU eq (parent atom), with n = 1.5 for O and n = 1.2 for N. The 3-hydroxyl group was found to be disordered over two positions. The anisotropic displacement ellipsoids were constrained to be equal for the two hydroxyl-O atoms and the major component had a site occupancy factor = 0.780 (4).  Dimethyl 4-(3-hydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The 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 > 2σ(F 2 ) is used only for calculating Rfactors(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. (