2-Amino-4-(2-methoxy­phen­yl)-7,7-dimethyl-5-oxo-5,6,7,8-tetra­hydro-4H-chromene-3-carbonitrile and 2-amino-4-(2-methoxy­phen­yl)-7,7-dimethyl-3-nitro-4,6,7,8-tetra­hydro-5H-chromen-5-one hemihydrate

Calculations of the conformational preferences of the methoxy­phenyl substituent with respect to the pyran ring have been carried out for the two title compounds, C₁₉H₂₀N₂O₃, (II), and C₁₈H₂₀N₂O₅·0.5H₂O, (III). In both mol­ecules, the heterocyclic ring adopts a flattened boat conformation and the fused cyclo­hexenone ring adopts a `sofa' conformation. The dihedral angles between these two flat fragments are 14.5 (1) and 9.3 (1)° in (II) and (III), respectively. In both mol­ecules, the methoxy group of the pseudo-axial aryl substituent is syn with respect to the pyran ring. The dihedral angles between the 2-methoxy­phenyl rings and the flat parts of the pyran rings are 86.3 (1) and 87.0 (1)°, respectively. In the crystal structure of (II), inter­molecular N—H...N and N—H...O hydrogen bonds link mol­ecules into a three-dimensional framework. In the crystal structure of (III), a strong intra­molecular N—H...O hydrogen bond links the flat conjugated H—N—C=C—N—O fragment into a six-membered ring. In (III), the water mol­ecule lies on a twofold axis and forms bifurcated O—H...O hydrogen bonds with the NO₂ group of the mol­ecule. Also in (III), hydrogen bonds link the organic and water mol­ecules into infinite tapes along the c axis.

S1. Comment

The present investigation is a continuation of our systematic work that includes the syntheses and structural studies of unsaturated nitriles as potential nonlinear optical materials (Nesterov et al., 2000, 2001a,b) and heterocyclic compounds that may be obtained using such nitriles (Nesterov & Viltchinskaia, 2001; Nesterov et al., 2004; Nesterova et al., 2004). Some 4H-pyran derivatives are potentially bioactive compounds and can be used as calcium antagonists (Suarez et al., 2002). Such heterocyclic compounds have structures similar to those of the well known 1,4-dihydropyridines (Triggle et al., 1980; Bossert et al., 1981, 1989; Kokubun & Reuter, 1984), which exhibit high bioactivities. Thus, there has been a growing interest in the structures of 4H-pyran derivatives (Florencio & Garcia-Blanco, 1987; Bellanato et al., 1988; Lokaj et al., 1990; Marco et al., 1993; Suarez et al., 2002).

Syntheses and X-ray structural investigations have been carried out for compounds (II) and (III) (Figs. 1 and 2). Most of the geometric parameters are very similar to the standard values (Allen et al., 1987), and very close to our and literature data for similar 4H-pyran derivatives (Kislyi et al., 1999; Suarez et al., 2002; Nesterov et al., 2004).

The X-ray analyses show that molecules (II) and (III) have slightly different conformations. The pyran ring in both structures adopts a flattened boat conformation, with a deviation of atoms O1 and C4 from the C2/C3/C5/C10 plane [planar within 0.008 (2) and 0.001 (2) Å, respectively] of 0.151 (2) and 0.203 (2) Å in (II), and −0.108 (2) and −0.218 (2) Å in (III), respectively. The bending of the ring along the lines O1···C4, C2···C10 and C3···C5 is, respectively, equal to 16.6 (2), 12.4 (2) and 13.2 (2)° in (II), and 15.2 (2), 9.0 (2) and 14.5 (2)° in (III). According to our previous work and literature data, the pyran ring is flexible, but usually adopts a flattened boat conformation. In both molecules, the fused cyclohexenone ring adopts a sofa conformation; atom C8 deviates from the C7/C6/C5/C10/C9 plane [planar within 0.030 (1) and 0.024 (1) Å, respectively] of 0.636 (1) and −0.666 (2) Å, respectively. The dihedral angle between these two flat fragments is equal to 14.5 (1) and 9.3 (1)° in (II) and (III), respectively. In both molecules, the o-methoxyphenyl substituent is anti relative to the H atom bonded to C4 [the H4A—C4—C13—C14 angles are −167 and 178°, and the C4—C13—C14—O3 angles are 1.9 (2) and 2.1 (3)°, respectively]. The phenyl substituents occupy pseudo-axial positions and form dihedral angles with the flat moieties of the pyran rings in (II) and (III) equal to 86.3 (1) and 87.0 (1)°, respectively. Such mutual orientation of these fragments and the flatness of the heterocyclic rings leads to O···C intramolecular steric interactions [O3···C5 = 2.911 (3) Å and O3···C10 = 3.109 (3) Å in molecule (II), and O3···C2 = 3.074 (3) Å, O3···C3 = 3.006 (3) Å, O3···C5 = 2.969 (3) Å and O3···C10 = 3.018 (3) Å in (III)]. These are shorter than the sum of the van der Waals radii of O and C (Rowland & Taylor, 1996), especially in the case of (II). Such steric hindrance causes elongation of the C4—C13 bond lengths to 1.525 (2) and 1.527 (3) Å, respectively, in comparison with neighboring Csp³—Csp² distances that are equal to standard values (Allen et al., 1987).

As was described previously for related compounds (Kislyi et al., 1999; Nesterov et al., 2001, 2004; Nesterova et al., 2004), there is a conjugation [especially in (III)] between the donor (NH₂) and the acceptor [CN in (II) and NO₂ in (III)] groups via the C2═C3 double bond (Tables 1 and 3). Thus, in both molecules the C2—N1 distances are shorter than the average conjugated C—N single bond (1.370 Å) found in the Cambridge Structural Database (Allen, 2002). In contrast, the C2═C3 bond lengths are elongated in comparison with the C5═C10 bond length and the standard value (Allen et al., 1987). Variations of the other bond lengths in the flat fragments are less distinct in (II). However, in (III) the C3—N2 distance is considerably shorter than usual for C—NO₂ bonds (1.468 Å; Allen et al., 1987) and the N2—O4 is distinctly longer than the standard value (Allen et al., 1987).

In the crystal stucture of (II), both H atoms of the NH₂ group participate in intermolecular N—H···N and N—H···O hydrogen bonds that link the molecules into a three- dimensional framework (Fig. 3 and Table 2). In (III), a strong intramolecular N—H···O hydrogen bond links the flat conjugated fragment H—N—C=C—N—O into a six-membered ring. The water molecule lies on a twofold axis and forms bifurcated O—H.·O hydrogen bonds with the NO₂ group of the molecule. In the crystal structure, hydrogen bonds link the product and water molecules into infinite tapes along the c axis (Fig. 4 and Table 4).

Analysis of the crystal packing shows that in (III) there is only one intermolecular steric contact [O4···O4ⁱ = 2.894 (2) Å; symmetry code: (i) −x, 2 − y, −z], which is equal to the sum of the van der Waals radii of the O atoms (Rowland & Taylor, 1996). The other geometric parameters in (II) and (III) have standard values (Allen et al., 1987).

Using computational methods (GAUSSIAN03; Frisch et al., 2003), we explored the conformational preferences of the methoxyphenyl substituent with respect to the pyran ring in molecules (II) and (III). This was done first at the AM1 level by minimizing the conformer found in the crystal, and then rotating the H4—C4—C13—C14 angle by 10° increments and minimizing the conformations encountered until the original conformer was generated once again. For the molecules of both (II) and (III), two minima were found. The first has the methoxy substituent on the phenyl ring syn to the pyran ring (H4—C4—C13—C14 angle close to −180°), similar to the configuration observed in the crystal structures (Figs. 1 and 2). The second has the methoxy substituent on the phenyl ring anti to the pyran ring (H4—C4—C13—C14 angle close to 0°). For compound (II) at the AM1 level, the anti conformation is predicted to be the global minimum, being 1.8 kcal mol⁻¹ more stable than the syn minimum and 6.4 kcal mol⁻¹ more stable than the highest energy conformation. In contrast, higher level restricted Hartree–Fock calculations on the two minima of (II) [basis set 6–311++G(d,p)] predict that the syn conformer observed in the crystal is more stable than the anti conformer by 0.9 kcal mol⁻¹. AM1 calculations on (III) gave similar results, with the anti conformer predicted to be more stable than the syn by 0.5 kcal mol⁻¹ and also more stable than the highest energy conformation by 5.1 kcal mol⁻¹. Similar to the results with (II), the higher level ab initio calculations (same basis set used) predict the conformer observed in the crystal of (III) to be the minimum energy conformer: the syn conformer is predicted to be 2.2 kcal mol⁻¹ more stable than the anti.

S2. Experimental

Compounds (II) and (III) were obtained by the reaction of (2-methoxybenzylidene)malononitrile (Ia) or trans-1-cyano-2- (2-methoxyphenyl)-1-nitroethylene (Ib) with 5,5-dimethylcyclohexane-1,3-dione (dimedone), respectively, according to literature procedures (Kislyi et al., 1999; Nesterov & Viltchinskaia, 2001). The precipitates were isolated and recrystallized from acetonitrile for (II) and ethanol for (III) [melting point 474 K, yield 96% for (II), and 435 K (hemihydrate), yield 71% for (III)]. Both compounds were characterized by ¹H and ¹³C NMR spectroscopy. The crystals were grown by slow isothermic evaporation of solutions in acetonitrile for (II) and ethanol for (III).

S3. Refinement

In both organic molecules, the H atoms were placed in geometrically calculated positions and refined using a riding model, with C—H distances of 0.95 Å in (II) and 0.93 Å in (III) for aromatic H atoms, 0.98 and 0.96 Å in (II) and (III), respectively, for CH₃, 0.99 and 0.97 Å, respectively, for CH₂, 1.0 and 0.98 Å, respectively, for CH, and 0.88 and 0.86 Å, respectively, for NH₂ groups, with U_iso(H) =1.2U_eq(C,N) or 1.5U_eq(C). In (III), the H atom of the water molecule was located in a difference Fourier map and refined isotropically.

Computing details

Data collection: P3/PC (Siemens, 1989) for (II); CAD-4 Software (Enraf–Nonius, 1989) for (III). Cell refinement: P3/PC for (II); CAD-4 Software for (III). For both compounds, data reduction: SHELXTL-Plus (Sheldrick, 1994); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus; software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. : A view of (II), showing the atom numbering used. The non-H atoms are shown with displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. : A view of (III), showing the atom numbering used. The non-H atoms are shown with displacement ellipsoids drawn at the 50% probability level. Dashed lines indicate the intramolecular N—H···O hydrogen bond and the O—H···O bifurcated hydrogen bonds.
	Fig. 3. : A projection of the crystal packing of (II) along the a axis. [Symmetry codes: (i) 1 − x, 1 − y, 1 − z; (ii) 1/2 + x, 1/2 − y, 1/2 + z.]
	Fig. 4. : A projection of the crystal packing of (III) along the b axis. [Symmetry codes: (i) −x, 2 − y, −z.]

(II) 2-Amino-4-(2-methoxyphenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro- 4H-chromene-3-carbonitrile

Crystal data

C19H20N2O3	F(000) = 688
Mr = 324.37	Dx = 1.289 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 8.7941 (18) Å	Cell parameters from 24 reflections
b = 17.450 (4) Å	θ = 11–12°
c = 11.007 (2) Å	µ = 0.09 mm^−1
β = 98.174 (16)°	T = 153 K
V = 1671.9 (6) Å^3	Prism, colorless
Z = 4	0.45 × 0.30 × 0.25 mm

Data collection

Siemens P3/PC diffractometer	Rint = 0.027
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.2°
Graphite monochromator	h = 0→10
ω/2θ scans	k = 0→20
3105 measured reflections	l = −13→12
2907 independent reflections	3 standard reflections every 97 reflections
2562 reflections with I > 2σ(I)	intensity decay: 3%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.094	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.05P)^2 + 0.54P] where P = (Fo^2 + 2Fc^2)/3
2907 reflections	(Δ/σ)max < 0.001
220 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.20 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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. All H atoms were placed in geometrically calculated positions and refined using a riding model with C—H distances of 0.95 Å for aromatic H atoms, 0.98 Å for CH₃, 0.99 Å for CH₂, 1.0 Å for CH, 0.88 Å for NH₂ group.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.52493 (11)	0.27471 (5)	0.73529 (8)	0.0236 (2)
O2	0.19526 (12)	0.11434 (6)	0.47133 (9)	0.0329 (3)
O3	0.67493 (11)	0.17220 (6)	0.53370 (9)	0.0302 (2)
N1	0.58034 (15)	0.39678 (6)	0.70743 (10)	0.0298 (3)
H1A	0.5806	0.4399	0.6661	0.036*
H1B	0.6220	0.3950	0.7849	0.036*
N2	0.40686 (14)	0.44098 (7)	0.39152 (10)	0.0300 (3)
C1	0.42754 (15)	0.38942 (7)	0.45707 (11)	0.0213 (3)
C2	0.51683 (15)	0.33417 (7)	0.65266 (12)	0.0213 (3)
C3	0.44752 (15)	0.32487 (7)	0.53571 (11)	0.0201 (3)
C4	0.38235 (15)	0.24846 (7)	0.48559 (11)	0.0197 (3)
H4	0.2759	0.2591	0.4438	0.024*
C5	0.36591 (14)	0.19641 (7)	0.59223 (11)	0.0195 (3)
C6	0.26133 (15)	0.13056 (7)	0.57348 (12)	0.0223 (3)
C7	0.23123 (16)	0.08633 (8)	0.68532 (12)	0.0262 (3)
H7A	0.2005	0.0334	0.6602	0.031*
H7B	0.1439	0.1103	0.7187	0.031*
C8	0.36923 (15)	0.08265 (7)	0.78723 (12)	0.0236 (3)
C9	0.42223 (16)	0.16480 (7)	0.81714 (12)	0.0243 (3)
H9A	0.3488	0.1898	0.8649	0.029*
H9B	0.5238	0.1635	0.8691	0.029*
C10	0.43407 (15)	0.21127 (7)	0.70551 (11)	0.0203 (3)
C11	0.49962 (17)	0.03628 (8)	0.74447 (14)	0.0306 (3)
H11A	0.5878	0.0352	0.8098	0.046*
H11B	0.5300	0.0601	0.6710	0.046*
H11C	0.4645	−0.0162	0.7252	0.046*
C12	0.32088 (17)	0.04652 (8)	0.90222 (13)	0.0307 (3)
H12A	0.4078	0.0473	0.9687	0.046*
H12B	0.2886	−0.0066	0.8846	0.046*
H12C	0.2352	0.0757	0.9271	0.046*
C13	0.47114 (15)	0.21655 (7)	0.38753 (11)	0.0214 (3)
C14	0.61470 (15)	0.18056 (7)	0.41270 (12)	0.0238 (3)
C15	0.69003 (17)	0.15555 (8)	0.31681 (13)	0.0294 (3)
H15	0.7869	0.1308	0.3341	0.035*
C16	0.62341 (19)	0.16680 (8)	0.19625 (14)	0.0335 (4)
H16	0.6753	0.1498	0.1312	0.040*
C17	0.4833 (2)	0.20220 (9)	0.16999 (13)	0.0345 (4)
H17	0.4381	0.2099	0.0873	0.041*
C18	0.40874 (17)	0.22661 (8)	0.26574 (12)	0.0270 (3)
H18	0.3117	0.2510	0.2473	0.032*
C19	0.80071 (18)	0.12026 (9)	0.56157 (16)	0.0382 (4)
H19A	0.8246	0.1141	0.6507	0.057*
H19B	0.8908	0.1406	0.5293	0.057*
H19C	0.7729	0.0704	0.5238	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0328 (5)	0.0173 (5)	0.0187 (4)	−0.0018 (4)	−0.0030 (4)	0.0024 (3)
O2	0.0389 (6)	0.0355 (6)	0.0222 (5)	−0.0132 (5)	−0.0025 (4)	0.0006 (4)
O3	0.0263 (5)	0.0358 (6)	0.0275 (5)	0.0088 (4)	0.0004 (4)	−0.0039 (4)
N1	0.0465 (8)	0.0189 (6)	0.0208 (6)	−0.0056 (5)	−0.0061 (5)	0.0019 (4)
N2	0.0389 (7)	0.0238 (6)	0.0255 (6)	−0.0031 (5)	−0.0013 (5)	0.0040 (5)
C1	0.0225 (6)	0.0222 (7)	0.0188 (6)	−0.0014 (5)	0.0022 (5)	−0.0024 (5)
C2	0.0254 (7)	0.0176 (6)	0.0211 (6)	0.0021 (5)	0.0034 (5)	0.0017 (5)
C3	0.0234 (6)	0.0180 (6)	0.0194 (6)	0.0010 (5)	0.0041 (5)	0.0012 (5)
C4	0.0211 (6)	0.0198 (6)	0.0177 (6)	−0.0002 (5)	0.0011 (5)	0.0002 (5)
C5	0.0211 (6)	0.0186 (6)	0.0191 (6)	0.0027 (5)	0.0040 (5)	0.0006 (5)
C6	0.0227 (7)	0.0229 (7)	0.0210 (7)	0.0009 (5)	0.0021 (5)	0.0001 (5)
C7	0.0264 (7)	0.0272 (7)	0.0249 (7)	−0.0049 (6)	0.0032 (6)	0.0039 (5)
C8	0.0256 (7)	0.0211 (7)	0.0239 (7)	−0.0004 (5)	0.0027 (5)	0.0044 (5)
C9	0.0320 (7)	0.0217 (7)	0.0183 (6)	0.0027 (5)	0.0003 (5)	0.0029 (5)
C10	0.0230 (6)	0.0155 (6)	0.0224 (6)	0.0026 (5)	0.0030 (5)	−0.0002 (5)
C11	0.0330 (8)	0.0200 (7)	0.0401 (8)	0.0021 (6)	0.0090 (6)	0.0042 (6)
C12	0.0333 (8)	0.0305 (8)	0.0285 (7)	0.0000 (6)	0.0049 (6)	0.0096 (6)
C13	0.0265 (7)	0.0176 (6)	0.0206 (6)	−0.0062 (5)	0.0055 (5)	−0.0021 (5)
C14	0.0263 (7)	0.0189 (6)	0.0268 (7)	−0.0062 (5)	0.0059 (5)	−0.0032 (5)
C15	0.0327 (8)	0.0198 (7)	0.0391 (8)	−0.0051 (6)	0.0167 (6)	−0.0043 (6)
C16	0.0498 (9)	0.0241 (7)	0.0319 (8)	−0.0102 (7)	0.0238 (7)	−0.0064 (6)
C17	0.0517 (10)	0.0329 (8)	0.0205 (7)	−0.0094 (7)	0.0108 (6)	−0.0021 (6)
C18	0.0334 (8)	0.0261 (7)	0.0214 (7)	−0.0054 (6)	0.0038 (6)	−0.0002 (5)
C19	0.0292 (8)	0.0387 (9)	0.0452 (9)	0.0110 (7)	0.0004 (7)	−0.0024 (7)

Geometric parameters (Å, º)

O1—C2	1.3749 (15)	C8—C11	1.5311 (19)
O1—C10	1.3773 (16)	C9—C10	1.4882 (18)
O2—C6	1.2232 (16)	C9—H9A	0.9900
O3—C14	1.3693 (17)	C9—H9B	0.9900
O3—C19	1.4292 (17)	C11—H11A	0.9800
N1—C2	1.3317 (17)	C11—H11B	0.9800
N1—H1A	0.8800	C11—H11C	0.9800
N1—H1B	0.8800	C12—H12A	0.9800
N2—C1	1.1514 (17)	C12—H12B	0.9800
C1—C3	1.4162 (18)	C12—H12C	0.9800
C2—C3	1.3535 (18)	C13—C18	1.3857 (19)
C3—C4	1.5235 (17)	C13—C14	1.4019 (19)
C4—C5	1.5073 (17)	C14—C15	1.394 (2)
C4—C13	1.5246 (18)	C15—C16	1.386 (2)
C4—H4	1.0000	C15—H15	0.9500
C5—C10	1.3299 (18)	C16—C17	1.372 (2)
C5—C6	1.4679 (18)	C16—H16	0.9500
C6—C7	1.5080 (18)	C17—C18	1.385 (2)
C7—C8	1.5323 (19)	C17—H17	0.9500
C7—H7A	0.9900	C18—H18	0.9500
C7—H7B	0.9900	C19—H19A	0.9800
C8—C12	1.5275 (18)	C19—H19B	0.9800
C8—C9	1.5288 (18)	C19—H19C	0.9800
C2—O1—C10	118.38 (10)	H9A—C9—H9B	107.8
C14—O3—C19	117.19 (11)	C5—C10—O1	123.28 (11)
C2—N1—H1A	120.0	C5—C10—C9	126.36 (12)
C2—N1—H1B	120.0	O1—C10—C9	110.35 (11)
H1A—N1—H1B	120.0	C8—C11—H11A	109.5
N2—C1—C3	177.83 (14)	C8—C11—H11B	109.5
N1—C2—C3	129.20 (12)	H11A—C11—H11B	109.5
N1—C2—O1	109.92 (11)	C8—C11—H11C	109.5
C3—C2—O1	120.85 (11)	H11A—C11—H11C	109.5
C2—C3—C1	119.08 (11)	H11B—C11—H11C	109.5
C2—C3—C4	123.00 (11)	C8—C12—H12A	109.5
C1—C3—C4	117.85 (11)	C8—C12—H12B	109.5
C5—C4—C3	108.55 (10)	H12A—C12—H12B	109.5
C5—C4—C13	116.54 (11)	C8—C12—H12C	109.5
C3—C4—C13	111.83 (10)	H12A—C12—H12C	109.5
C5—C4—H4	106.4	H12B—C12—H12C	109.5
C3—C4—H4	106.4	C18—C13—C14	118.01 (12)
C13—C4—H4	106.4	C18—C13—C4	117.80 (12)
C10—C5—C6	118.31 (12)	C14—C13—C4	124.13 (12)
C10—C5—C4	122.16 (12)	O3—C14—C15	122.92 (13)
C6—C5—C4	119.32 (11)	O3—C14—C13	116.93 (12)
O2—C6—C5	121.10 (12)	C15—C14—C13	120.15 (13)
O2—C6—C7	121.10 (12)	C16—C15—C14	119.93 (14)
C5—C6—C7	117.72 (11)	C16—C15—H15	120.0
C6—C7—C8	113.97 (11)	C14—C15—H15	120.0
C6—C7—H7A	108.8	C17—C16—C15	120.67 (13)
C8—C7—H7A	108.8	C17—C16—H16	119.7
C6—C7—H7B	108.8	C15—C16—H16	119.7
C8—C7—H7B	108.8	C16—C17—C18	119.11 (14)
H7A—C7—H7B	107.7	C16—C17—H17	120.4
C12—C8—C9	108.71 (11)	C18—C17—H17	120.4
C12—C8—C11	110.21 (11)	C17—C18—C13	122.12 (14)
C9—C8—C11	110.06 (11)	C17—C18—H18	118.9
C12—C8—C7	109.82 (11)	C13—C18—H18	118.9
C9—C8—C7	107.69 (11)	O3—C19—H19A	109.5
C11—C8—C7	110.30 (11)	O3—C19—H19B	109.5
C10—C9—C8	112.83 (11)	H19A—C19—H19B	109.5
C10—C9—H9A	109.0	O3—C19—H19C	109.5
C8—C9—H9A	109.0	H19A—C19—H19C	109.5
C10—C9—H9B	109.0	H19B—C19—H19C	109.5
C8—C9—H9B	109.0
C10—O1—C2—N1	164.49 (11)	C6—C5—C10—O1	−174.89 (11)
C10—O1—C2—C3	−13.66 (17)	C4—C5—C10—O1	−0.10 (19)
N1—C2—C3—C1	−4.2 (2)	C6—C5—C10—C9	3.7 (2)
O1—C2—C3—C1	173.56 (11)	C4—C5—C10—C9	178.44 (12)
N1—C2—C3—C4	178.85 (13)	C2—O1—C10—C5	15.72 (18)
O1—C2—C3—C4	−3.39 (19)	C2—O1—C10—C9	−163.03 (11)
C2—C3—C4—C5	16.65 (17)	C8—C9—C10—C5	19.93 (19)
C1—C3—C4—C5	−160.33 (11)	C8—C9—C10—O1	−161.37 (11)
C2—C3—C4—C13	−113.30 (14)	C5—C4—C13—C18	134.31 (12)
C1—C3—C4—C13	69.72 (15)	C3—C4—C13—C18	−100.02 (13)
C3—C4—C5—C10	−14.85 (16)	C5—C4—C13—C14	−48.45 (17)
C13—C4—C5—C10	112.45 (14)	C3—C4—C13—C14	77.22 (15)
C3—C4—C5—C6	159.88 (11)	C19—O3—C14—C15	−15.06 (19)
C13—C4—C5—C6	−72.81 (15)	C19—O3—C14—C13	165.34 (12)
C10—C5—C6—O2	179.82 (12)	C18—C13—C14—O3	179.14 (11)
C4—C5—C6—O2	4.88 (19)	C4—C13—C14—O3	1.91 (18)
C10—C5—C6—C7	3.21 (18)	C18—C13—C14—C15	−0.47 (18)
C4—C5—C6—C7	−171.73 (11)	C4—C13—C14—C15	−177.70 (12)
O2—C6—C7—C8	149.85 (13)	O3—C14—C15—C16	−179.10 (12)
C5—C6—C7—C8	−33.53 (17)	C13—C14—C15—C16	0.5 (2)
C6—C7—C8—C12	172.26 (11)	C14—C15—C16—C17	−0.2 (2)
C6—C7—C8—C9	54.05 (15)	C15—C16—C17—C18	−0.1 (2)
C6—C7—C8—C11	−66.08 (15)	C16—C17—C18—C13	0.1 (2)
C12—C8—C9—C10	−165.46 (11)	C14—C13—C18—C17	0.18 (19)
C11—C8—C9—C10	73.74 (14)	C4—C13—C18—C17	177.59 (12)
C7—C8—C9—C10	−46.53 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···N2^i	0.88	2.18	3.041 (2)	166
N1—H1B···O2^ii	0.88	2.07	2.943 (2)	173

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1/2, −y+1/2, z+1/2.

(III) 2-amino-4-(2-methoxyphenyl)-7,7- dimethyl-3-nitro-4,6,7,8-tetrahydro-5H-chromen-5-one hemihydrate

Crystal data

C18H20N2O5·0.5H2O	F(000) = 1496
Mr = 353.37	Dx = 1.309 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 28.461 (5) Å	Cell parameters from 24 reflections
b = 9.456 (2) Å	θ = 10–11°
c = 15.860 (3) Å	µ = 0.10 mm^−1
β = 122.819 (11)°	T = 298 K
V = 3587.1 (13) Å^3	Prism, colorless
Z = 8	0.40 × 0.35 × 0.30 mm

Data collection

Enraf-Nonius CAD4 diffractometer	Rint = 0.038
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.5°
Graphite monochromator	h = 0→33
ω/2θ scans	k = 0→11
3162 measured reflections	l = −18→15
3097 independent reflections	3 standard reflections every 97 reflections
1749 reflections with I > 2σ(I)	intensity decay: 3%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.055	Hydrogen site location: mixed
wR(F^2) = 0.116	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0534P)^2] where P = (Fo^2 + 2Fc^2)/3
3097 reflections	(Δ/σ)max < 0.001
238 parameters	Δρmax = 0.13 e Å^−3
0 restraints	Δρmin = −0.16 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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. All H atoms were placed in geometrically calculated positions and refined using a riding model with C—H distances of 0.93 Å for aromatic H atoms, 0.96 Å for CH₃, 0.97 Å for CH₂, 0.98 Å for CH, 0.86 Å for NH₂ group. H-atom of H₂O was refined isotropically.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.13928 (6)	0.75954 (16)	0.25649 (11)	0.0400 (4)
O2	0.24467 (8)	0.5035 (2)	0.15911 (14)	0.0611 (5)
O3	0.08229 (7)	0.49236 (18)	0.14960 (13)	0.0514 (5)
O4	0.03503 (7)	0.92138 (19)	−0.02371 (14)	0.0597 (5)
O5	0.07335 (7)	0.7874 (2)	−0.08194 (13)	0.0573 (5)
N1	0.06979 (8)	0.9071 (2)	0.16535 (16)	0.0538 (6)
H1A	0.0729	0.9275	0.2210	0.065*
H1B	0.0449	0.9486	0.1108	0.065*
N2	0.06994 (8)	0.8275 (2)	−0.01045 (16)	0.0442 (5)
C1	0.04911 (13)	0.4232 (4)	0.1796 (2)	0.0756 (10)
H1C	0.0500	0.4768	0.2318	0.113*
H1D	0.0637	0.3302	0.2040	0.113*
H1E	0.0112	0.4160	0.1231	0.113*
C2	0.10300 (9)	0.8130 (2)	0.16369 (18)	0.0380 (6)
C3	0.10493 (9)	0.7671 (2)	0.08259 (17)	0.0364 (6)
C4	0.14294 (9)	0.6515 (2)	0.09016 (17)	0.0352 (6)
H4	0.1611	0.6848	0.0562	0.042*
C5	0.18823 (9)	0.6290 (2)	0.19887 (17)	0.0345 (5)
C6	0.23847 (10)	0.5492 (2)	0.22411 (18)	0.0401 (6)
C7	0.28288 (10)	0.5316 (3)	0.33391 (18)	0.0508 (7)
H7A	0.3081	0.6117	0.3557	0.061*
H7B	0.3044	0.4472	0.3423	0.061*
C8	0.25989 (10)	0.5200 (3)	0.40187 (18)	0.0433 (6)
C9	0.22386 (10)	0.6516 (3)	0.38185 (17)	0.0410 (6)
H9A	0.2033	0.6403	0.4141	0.049*
H9B	0.2480	0.7335	0.4113	0.049*
C10	0.18399 (9)	0.6766 (2)	0.27338 (17)	0.0336 (5)
C11	0.22439 (12)	0.3858 (3)	0.3764 (2)	0.0605 (8)
H11A	0.2113	0.3778	0.4208	0.091*
H11B	0.2467	0.3046	0.3842	0.091*
H11C	0.1929	0.3910	0.3083	0.091*
C12	0.30803 (12)	0.5166 (3)	0.51180 (19)	0.0657 (8)
H12A	0.2933	0.5104	0.5537	0.099*
H12B	0.3298	0.6014	0.5276	0.099*
H12C	0.3313	0.4359	0.5233	0.099*
C13	0.11270 (9)	0.5140 (2)	0.03904 (17)	0.0365 (6)
C14	0.08367 (10)	0.4360 (2)	0.07124 (18)	0.0421 (6)
C15	0.05859 (12)	0.3089 (3)	0.0255 (2)	0.0600 (8)
H15	0.0401	0.2559	0.0482	0.072*
C16	0.06126 (12)	0.2615 (3)	−0.0545 (2)	0.0686 (9)
H16	0.0445	0.1762	−0.0853	0.082*
C17	0.08823 (12)	0.3389 (3)	−0.0884 (2)	0.0626 (8)
H17	0.0891	0.3079	−0.1432	0.075*
C18	0.11411 (10)	0.4634 (3)	−0.04077 (19)	0.0484 (7)
H18	0.1331	0.5147	−0.0633	0.058*
O1W	0.0000	0.9839 (4)	−0.2500	0.1011 (13)
H1W	0.0245 (17)	0.920 (4)	−0.194 (3)	0.160 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0359 (9)	0.0438 (10)	0.0390 (10)	0.0109 (8)	0.0195 (8)	0.0027 (8)
O2	0.0560 (11)	0.0794 (14)	0.0582 (12)	0.0177 (11)	0.0377 (11)	−0.0015 (11)
O3	0.0522 (11)	0.0603 (12)	0.0530 (11)	−0.0176 (9)	0.0359 (10)	−0.0064 (9)
O4	0.0448 (11)	0.0553 (11)	0.0650 (13)	0.0151 (10)	0.0207 (10)	0.0214 (10)
O5	0.0568 (12)	0.0686 (13)	0.0405 (11)	−0.0009 (10)	0.0225 (10)	0.0080 (9)
N1	0.0434 (13)	0.0545 (14)	0.0551 (15)	0.0208 (11)	0.0213 (12)	0.0063 (11)
N2	0.0362 (12)	0.0413 (13)	0.0461 (14)	−0.0048 (10)	0.0165 (11)	0.0086 (11)
C1	0.079 (2)	0.095 (2)	0.076 (2)	−0.0282 (19)	0.058 (2)	−0.0058 (18)
C2	0.0282 (13)	0.0346 (14)	0.0452 (16)	0.0011 (11)	0.0159 (13)	0.0055 (11)
C3	0.0301 (12)	0.0346 (14)	0.0363 (14)	−0.0020 (11)	0.0127 (11)	0.0044 (11)
C4	0.0310 (13)	0.0403 (13)	0.0347 (14)	−0.0051 (11)	0.0181 (12)	0.0008 (11)
C5	0.0299 (13)	0.0341 (13)	0.0389 (14)	0.0005 (10)	0.0183 (12)	0.0016 (11)
C6	0.0376 (14)	0.0419 (14)	0.0483 (16)	0.0013 (11)	0.0282 (14)	−0.0015 (12)
C7	0.0371 (14)	0.0631 (17)	0.0502 (17)	0.0140 (13)	0.0225 (14)	0.0019 (14)
C8	0.0367 (14)	0.0485 (16)	0.0402 (14)	0.0114 (12)	0.0180 (12)	0.0041 (12)
C9	0.0385 (14)	0.0448 (15)	0.0379 (15)	0.0068 (12)	0.0194 (13)	0.0016 (11)
C10	0.0265 (12)	0.0332 (13)	0.0388 (15)	0.0020 (10)	0.0163 (12)	0.0005 (11)
C11	0.0644 (19)	0.0480 (18)	0.074 (2)	0.0139 (14)	0.0411 (17)	0.0114 (15)
C12	0.0567 (17)	0.082 (2)	0.0470 (17)	0.0262 (16)	0.0209 (15)	0.0101 (16)
C13	0.0325 (13)	0.0380 (14)	0.0350 (13)	−0.0021 (11)	0.0156 (11)	0.0009 (11)
C14	0.0404 (14)	0.0449 (15)	0.0397 (15)	−0.0046 (12)	0.0209 (13)	−0.0035 (12)
C15	0.0606 (18)	0.0521 (17)	0.073 (2)	−0.0190 (14)	0.0402 (17)	−0.0077 (15)
C16	0.072 (2)	0.0524 (18)	0.084 (2)	−0.0207 (16)	0.044 (2)	−0.0269 (17)
C17	0.068 (2)	0.0635 (19)	0.066 (2)	−0.0122 (16)	0.0429 (18)	−0.0247 (16)
C18	0.0506 (16)	0.0500 (16)	0.0509 (17)	−0.0079 (13)	0.0316 (14)	−0.0094 (14)
O1W	0.171 (4)	0.064 (2)	0.0425 (19)	0.000	0.041 (2)	0.000

Geometric parameters (Å, º)

O1—C2	1.357 (3)	C7—H7B	0.9700
O1—C10	1.391 (2)	C8—C12	1.526 (3)
O2—C6	1.215 (3)	C8—C9	1.532 (3)
O3—C14	1.372 (3)	C8—C11	1.534 (4)
O3—C1	1.426 (3)	C9—C10	1.479 (3)
O4—N2	1.262 (2)	C9—H9A	0.9700
O5—N2	1.248 (2)	C9—H9B	0.9700
N1—C2	1.309 (3)	C11—H11A	0.9600
N1—H1A	0.8600	C11—H11B	0.9600
N1—H1B	0.8600	C11—H11C	0.9600
N2—C3	1.379 (3)	C12—H12A	0.9600
C1—H1C	0.9600	C12—H12B	0.9600
C1—H1D	0.9600	C12—H12C	0.9600
C1—H1E	0.9600	C13—C18	1.374 (3)
C2—C3	1.386 (3)	C13—C14	1.395 (3)
C3—C4	1.497 (3)	C14—C15	1.385 (3)
C4—C5	1.507 (3)	C15—C16	1.385 (4)
C4—C13	1.527 (3)	C15—H15	0.9300
C4—H4	0.9800	C16—C17	1.365 (4)
C5—C10	1.330 (3)	C16—H16	0.9300
C5—C6	1.468 (3)	C17—C18	1.377 (4)
C6—C7	1.507 (3)	C17—H17	0.9300
C7—C8	1.538 (3)	C18—H18	0.9300
C7—H7A	0.9700	O1W—H1W	0.99 (4)
C2—O1—C10	119.85 (17)	C9—C8—C7	106.7 (2)
C14—O3—C1	118.2 (2)	C11—C8—C7	110.1 (2)
C2—N1—H1A	120.0	C10—C9—C8	112.10 (19)
C2—N1—H1B	120.0	C10—C9—H9A	109.2
H1A—N1—H1B	120.0	C8—C9—H9A	109.2
O5—N2—O4	120.3 (2)	C10—C9—H9B	109.2
O5—N2—C3	118.7 (2)	C8—C9—H9B	109.2
O4—N2—C3	121.1 (2)	H9A—C9—H9B	107.9
O3—C1—H1C	109.5	C5—C10—O1	122.3 (2)
O3—C1—H1D	109.5	C5—C10—C9	126.7 (2)
H1C—C1—H1D	109.5	O1—C10—C9	111.05 (19)
O3—C1—H1E	109.5	C8—C11—H11A	109.5
H1C—C1—H1E	109.5	C8—C11—H11B	109.5
H1D—C1—H1E	109.5	H11A—C11—H11B	109.5
N1—C2—O1	111.4 (2)	C8—C11—H11C	109.5
N1—C2—C3	128.6 (2)	H11A—C11—H11C	109.5
O1—C2—C3	120.0 (2)	H11B—C11—H11C	109.5
N2—C3—C2	119.6 (2)	C8—C12—H12A	109.5
N2—C3—C4	117.4 (2)	C8—C12—H12B	109.5
C2—C3—C4	123.0 (2)	H12A—C12—H12B	109.5
C3—C4—C5	109.13 (19)	C8—C12—H12C	109.5
C3—C4—C13	113.87 (18)	H12A—C12—H12C	109.5
C5—C4—C13	111.94 (18)	H12B—C12—H12C	109.5
C3—C4—H4	107.2	C18—C13—C14	118.2 (2)
C5—C4—H4	107.2	C18—C13—C4	119.8 (2)
C13—C4—H4	107.2	C14—C13—C4	122.1 (2)
C10—C5—C6	118.4 (2)	O3—C14—C15	123.5 (2)
C10—C5—C4	122.4 (2)	O3—C14—C13	116.1 (2)
C6—C5—C4	119.2 (2)	C15—C14—C13	120.4 (2)
O2—C6—C5	121.3 (2)	C16—C15—C14	119.5 (3)
O2—C6—C7	121.6 (2)	C16—C15—H15	120.3
C5—C6—C7	117.0 (2)	C14—C15—H15	120.3
C6—C7—C8	114.1 (2)	C17—C16—C15	120.6 (3)
C6—C7—H7A	108.7	C17—C16—H16	119.7
C8—C7—H7A	108.7	C15—C16—H16	119.7
C6—C7—H7B	108.7	C16—C17—C18	119.3 (3)
C8—C7—H7B	108.7	C16—C17—H17	120.3
H7A—C7—H7B	107.6	C18—C17—H17	120.3
C12—C8—C9	109.8 (2)	C13—C18—C17	122.0 (2)
C12—C8—C11	109.8 (2)	C13—C18—H18	119.0
C9—C8—C11	110.26 (19)	C17—C18—H18	119.0
C12—C8—C7	110.0 (2)
C10—O1—C2—N1	−168.99 (19)	C11—C8—C9—C10	−70.9 (3)
C10—O1—C2—C3	10.5 (3)	C7—C8—C9—C10	48.7 (3)
O5—N2—C3—C2	178.1 (2)	C6—C5—C10—O1	176.51 (19)
O4—N2—C3—C2	−2.0 (3)	C4—C5—C10—O1	−4.8 (3)
O5—N2—C3—C4	−3.0 (3)	C6—C5—C10—C9	−3.5 (4)
O4—N2—C3—C4	176.96 (19)	C4—C5—C10—C9	175.3 (2)
N1—C2—C3—N2	2.8 (4)	C2—O1—C10—C5	−10.6 (3)
O1—C2—C3—N2	−176.52 (19)	C2—O1—C10—C9	169.43 (19)
N1—C2—C3—C4	−176.1 (2)	C8—C9—C10—C5	−22.0 (3)
O1—C2—C3—C4	4.6 (3)	C8—C9—C10—O1	158.00 (18)
N2—C3—C4—C5	163.82 (18)	C3—C4—C13—C18	117.0 (2)
C2—C3—C4—C5	−17.3 (3)	C5—C4—C13—C18	−118.6 (2)
N2—C3—C4—C13	−70.3 (3)	C3—C4—C13—C14	−63.5 (3)
C2—C3—C4—C13	108.6 (2)	C5—C4—C13—C14	60.8 (3)
C3—C4—C5—C10	17.3 (3)	C1—O3—C14—C15	−5.9 (4)
C13—C4—C5—C10	−109.7 (2)	C1—O3—C14—C13	174.6 (2)
C3—C4—C5—C6	−163.98 (19)	C18—C13—C14—O3	−178.5 (2)
C13—C4—C5—C6	69.0 (3)	C4—C13—C14—O3	2.1 (3)
C10—C5—C6—O2	−179.8 (2)	C18—C13—C14—C15	2.0 (4)
C4—C5—C6—O2	1.5 (3)	C4—C13—C14—C15	−177.5 (2)
C10—C5—C6—C7	−2.1 (3)	O3—C14—C15—C16	178.8 (3)
C4—C5—C6—C7	179.1 (2)	C13—C14—C15—C16	−1.7 (4)
O2—C6—C7—C8	−149.1 (2)	C14—C15—C16—C17	−0.1 (5)
C5—C6—C7—C8	33.3 (3)	C15—C16—C17—C18	1.6 (5)
C6—C7—C8—C12	−174.7 (2)	C14—C13—C18—C17	−0.4 (4)
C6—C7—C8—C9	−55.6 (3)	C4—C13—C18—C17	179.0 (2)
C6—C7—C8—C11	64.1 (3)	C16—C17—C18—C13	−1.4 (4)
C12—C8—C9—C10	168.0 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···O4	0.86	2.01	2.602 (3)	125
N1—H1B···O4^i	0.86	2.28	3.052 (3)	150
N1—H1A···O1W^i	0.86	2.50	3.115 (3)	129
O1W—H1W···O5	0.99 (4)	1.99 (4)	2.980 (3)	179 (5)
O1W—H1W···O4	0.99 (4)	2.55 (4)	3.216 (3)	125 (5)

Symmetry code: (i) −x, −y+2, −z.