Diethyl 2,6-dimethyl-4-phenyl-1,4-dihydro­pyridine-3,5-dicarboxyl­ate

Bai, M.-S.; Chen, Y.-Y.; Niu, D.-L.; Peng, L.

doi:10.1107/S1600536809009118

organic compounds

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ISSN: 2056-9890

Volume 65| Part 4| April 2009| Page o799

doi:10.1107/S1600536809009118

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Diethyl 2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate

Ming-Sheng Bai,^a ^* Yan-Yun Chen,^a Dong-Ling Niu ^a and Li Peng ^a

^aCollege of Life Science, Ningxia University, Yinchuan 750021, People's Republic of China
^*Correspondence e-mail: bai_mingsheng@163.com

(Received 24 February 2009; accepted 12 March 2009; online 19 March 2009)

The title molecule, C₁₉H₂₃NO₄, was synthesized by the reaction of benzaldehyde, ethyl acetoacetate and NH₄HCO₃. The dihydropyridine ring adopts a flattened boat conformation and the plane of the base of the boat forms a dihedral angle of 88.78 (9)° with the phenyl ring. The packing is stabilized by strong intermolecular N—H⋯O and weak intermolecular C—H⋯O hydrogen bonds.

Related literature

For general background, see: Cutshall et al. (2002 ); Henry (2004 ). For the crystal structure of the related compound diethyl 2,6-dimethyl-4-styryl-1,4-dihydropyridine-3,5-dicarboxylate, see: Wang et al., (2007 ). For hydrogen bond definitions, see: Desiraju & Steiner (1999 ).

Experimental

Crystal data

C₁₉H₂₃NO₄
M_r = 329.38
Monoclinic, P 2₁ /c
a = 9.7502 (12) Å
b = 7.3854 (9) Å
c = 24.326 (2) Å
β = 92.567 (1)°
V = 1749.9 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.50 × 0.46 × 0.32 mm

Data collection

Siemens SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.958, T_max = 0.973
8718 measured reflections
3084 independent reflections
1989 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.045
wR(F²) = 0.131
S = 1.01
3084 reflections
225 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O4ⁱ	0.81 (3)	2.19 (3)	2.986 (3)	168 (3)
C3—H3⋯O1	0.98	2.35	2.733 (3)	103
C3—H3⋯O4	0.98	2.43	2.816 (3)	103
C7—H7⋯O1	0.93	2.55	3.169 (3)	124
C12—H12C⋯O2	0.96	2.27	2.841 (3)	116
C15—H15A⋯O3	0.96	2.42	2.762 (3)	101
C8—H8⋯O2ⁱⁱ	0.93	2.51	3.387 (3)	157
Symmetry codes: (i) x, y+1, z; (ii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: SMART (Siemens, 1996 ); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809009118/fb2141sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809009118/fb2141Isup2.hkl

checkCIF report

Comment top

The development of new methods for the synthesis of substituted pyridines is a motive for the current study. Substituted pyridines attract the interest because of their presence in numerous natural products along with a wide spectrum of their physiological activities (Cutshall et al., 2002). Pyridine derivatives and their complexes have been studied for their fungicidal and antibacterial effects, as well as antiviral drugs (Henry, 2004).

In this paper, we present the structure of diethyl 2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate (Fig. 1).

The bond lengths and angles are normal and comparable to those observed in the reported diethyl 2,6-dimethyl-4-styryl-1,4-dihydropyridine-3,5-dicarboxylate (Wang et al., 2007).

In the crystal structure, the dihydropyridine ring adopts a flattened boat conformation and the plane of the base of the boat (C1/C2/C4/C5) contains 88.78 (9)° with the phenyl ring. There are present strong (Desiraju & Steiner, 1999) intermolecular N—H···O hydrogen bonds (Tab. 1) that link the molecules into chains propagated in the direction [010].

Related literature top

For general background, see: Cutshall et al. (2002); Henry (2004). For the crystal structure of the related compound diethyl 2,6-dimethyl-4-styryl-1,4-dihydropyridine-3,5-dicarboxylate, see: Wang et al., (2007). For hydrogen bond definitions, see: Desiraju & Steiner (1999).

Experimental top

Fresh benzaldehyde (6 mmol), ethyl acetoacetate (6 mmol) and NH₄HCO₃ (6 mmol) were mixed in a 50 ml flask. After the mixture had been stirred for 3 h at 293 K, the crude product was obtained. The title crystals were obtained by recrystallization from ethanol, affording the title compound as a yellow block crystalline solid. Elemental analysis: calculated for C₁₉H₂₃NO₄: C 69.28, H 7.04, N 4.25 weight%; found: C 69.29, H 7.85, N 4.29 weight%.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. The title molecule with the atomic numbering scheme. The displacement ellipsoids are shown at the 30% probability level.

Diethyl 2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylate top

Crystal data top

C₁₉H₂₃NO₄	F(000) = 704
M_r = 329.38	D_x = 1.250 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2ybc	Cell parameters from 2342 reflections
a = 9.7502 (12) Å	θ = 2.6–27.7°
b = 7.3854 (9) Å	µ = 0.09 mm⁻¹
c = 24.326 (2) Å	T = 298 K
β = 92.567 (1)°	Block, yellow
V = 1749.9 (3) Å³	0.50 × 0.46 × 0.32 mm
Z = 4

Data collection top

Siemens SMART 1000 CCD diffractometer	3084 independent reflections
Radiation source: fine-focus sealed tube	1989 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
ϕ and ω scans	θ_max = 25.0°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→11
T_min = 0.958, T_max = 0.973	k = −8→8
8718 measured reflections	l = −28→28

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.045	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.131	w = 1/[σ²(F_o²) + (0.0521P)² + 0.8294P] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max < 0.001
3084 reflections	Δρ_max = 0.22 e Å⁻³
225 parameters	Δρ_min = −0.18 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
85 constraints	Extinction coefficient: 0.0027 (8)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₁₉H₂₃NO₄	V = 1749.9 (3) Å³
M_r = 329.38	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 9.7502 (12) Å	µ = 0.09 mm⁻¹
b = 7.3854 (9) Å	T = 298 K
c = 24.326 (2) Å	0.50 × 0.46 × 0.32 mm
β = 92.567 (1)°

Data collection top

Siemens SMART 1000 CCD diffractometer	3084 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1989 reflections with I > 2σ(I)
T_min = 0.958, T_max = 0.973	R_int = 0.033
8718 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	0 restraints
wR(F²) = 0.131	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	Δρ_max = 0.22 e Å⁻³
3084 reflections	Δρ_min = −0.18 e Å⁻³
225 parameters

Special details top

Experimental. The sample was cut out from a larger slab crystal.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.3363 (2)	1.1267 (3)	0.55024 (8)	0.0405 (5)
H1	0.327 (3)	1.230 (4)	0.5394 (10)	0.049*
O1	0.57917 (16)	0.6975 (2)	0.65667 (7)	0.0476 (5)
O2	0.66266 (19)	0.9781 (3)	0.66376 (8)	0.0619 (6)
O3	0.14967 (17)	0.6965 (2)	0.46314 (6)	0.0468 (5)
O4	0.2624 (2)	0.5071 (2)	0.51964 (7)	0.0572 (5)
C1	0.4405 (2)	1.0939 (3)	0.58911 (9)	0.0376 (6)
C2	0.4587 (2)	0.9233 (3)	0.60794 (9)	0.0332 (5)
C3	0.3494 (2)	0.7821 (3)	0.59344 (8)	0.0324 (5)
H3	0.3937	0.6630	0.5927	0.039*
C4	0.2846 (2)	0.8200 (3)	0.53680 (8)	0.0318 (5)
C5	0.2721 (2)	0.9937 (3)	0.51905 (9)	0.0356 (5)
C6	0.2424 (2)	0.7790 (3)	0.63775 (8)	0.0323 (5)
C7	0.2655 (2)	0.6791 (4)	0.68509 (10)	0.0469 (6)
H7	0.3436	0.6070	0.6888	0.056*
C8	0.1752 (3)	0.6838 (4)	0.72719 (10)	0.0565 (8)
H8	0.1939	0.6175	0.7592	0.068*
C9	0.0577 (3)	0.7862 (4)	0.72192 (10)	0.0538 (7)
H9	−0.0035	0.7891	0.7501	0.065*
C10	0.0315 (3)	0.8837 (4)	0.67494 (10)	0.0497 (7)
H10	−0.0483	0.9524	0.6710	0.060*
C11	0.1231 (2)	0.8805 (3)	0.63333 (10)	0.0411 (6)
H11	0.1043	0.9481	0.6016	0.049*
C12	0.5222 (3)	1.2590 (3)	0.60462 (11)	0.0547 (7)
H12A	0.4892	1.3092	0.6379	0.082*
H12B	0.5126	1.3469	0.5756	0.082*
H12C	0.6172	1.2268	0.6102	0.082*
C13	0.5757 (2)	0.8760 (3)	0.64511 (9)	0.0387 (6)
C14	0.2330 (2)	0.6604 (3)	0.50671 (9)	0.0345 (5)
C15	0.1963 (3)	1.0650 (3)	0.46890 (10)	0.0508 (7)
H15A	0.2214	0.9965	0.4373	0.076*
H15B	0.2196	1.1900	0.4638	0.076*
H15C	0.0993	1.0543	0.4733	0.076*
C16	0.6846 (3)	0.6355 (4)	0.69600 (11)	0.0582 (8)
H16A	0.7690	0.7009	0.6902	0.070*
H16B	0.7019	0.5079	0.6898	0.070*
C17	0.6457 (4)	0.6618 (5)	0.75336 (12)	0.0819 (10)
H17A	0.6362	0.7888	0.7606	0.123*
H17B	0.7156	0.6118	0.7779	0.123*
H17C	0.5601	0.6018	0.7589	0.123*
C18	0.1024 (3)	0.5457 (3)	0.42944 (10)	0.0497 (7)
H18A	0.0477	0.4640	0.4507	0.060*
H18B	0.1800	0.4791	0.4162	0.060*
C19	0.0187 (4)	0.6213 (4)	0.38256 (12)	0.0757 (10)
H19A	−0.0562	0.6897	0.3962	0.114*
H19B	−0.0167	0.5242	0.3598	0.114*
H19C	0.0747	0.6988	0.3612	0.114*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0507 (13)	0.0230 (10)	0.0470 (12)	−0.0013 (10)	−0.0054 (10)	0.0019 (9)
O1	0.0410 (10)	0.0462 (11)	0.0542 (11)	0.0029 (8)	−0.0141 (8)	0.0051 (8)
O2	0.0573 (12)	0.0616 (12)	0.0647 (12)	−0.0180 (10)	−0.0213 (10)	0.0014 (10)
O3	0.0648 (11)	0.0324 (9)	0.0415 (9)	−0.0024 (8)	−0.0184 (8)	−0.0023 (7)
O4	0.0876 (14)	0.0259 (9)	0.0555 (11)	0.0040 (9)	−0.0245 (10)	0.0001 (8)
C1	0.0402 (14)	0.0340 (14)	0.0385 (13)	−0.0032 (11)	0.0009 (11)	−0.0053 (10)
C2	0.0344 (12)	0.0335 (13)	0.0316 (11)	−0.0016 (10)	0.0000 (10)	−0.0018 (10)
C3	0.0371 (13)	0.0252 (12)	0.0345 (12)	−0.0002 (10)	−0.0037 (10)	0.0014 (9)
C4	0.0373 (13)	0.0273 (12)	0.0305 (11)	0.0001 (10)	−0.0014 (10)	0.0010 (9)
C5	0.0425 (14)	0.0316 (12)	0.0327 (12)	0.0017 (11)	0.0009 (10)	0.0003 (10)
C6	0.0356 (13)	0.0285 (12)	0.0323 (12)	−0.0057 (10)	−0.0052 (9)	0.0015 (9)
C7	0.0388 (14)	0.0544 (17)	0.0468 (15)	−0.0019 (12)	−0.0055 (12)	0.0163 (12)
C8	0.0498 (16)	0.078 (2)	0.0414 (15)	−0.0118 (15)	−0.0034 (13)	0.0210 (14)
C9	0.0481 (16)	0.0715 (19)	0.0424 (15)	−0.0113 (15)	0.0079 (12)	0.0010 (14)
C10	0.0471 (15)	0.0519 (16)	0.0507 (16)	0.0061 (13)	0.0075 (13)	0.0032 (13)
C11	0.0452 (14)	0.0398 (14)	0.0382 (13)	0.0031 (12)	0.0006 (11)	0.0069 (11)
C12	0.0603 (17)	0.0389 (15)	0.0641 (17)	−0.0110 (13)	−0.0057 (14)	−0.0053 (13)
C13	0.0356 (13)	0.0459 (15)	0.0347 (13)	−0.0038 (12)	0.0019 (10)	−0.0027 (11)
C14	0.0421 (13)	0.0304 (13)	0.0309 (12)	−0.0003 (11)	−0.0005 (10)	0.0006 (10)
C15	0.0710 (18)	0.0355 (14)	0.0446 (15)	0.0015 (13)	−0.0099 (13)	0.0069 (11)
C16	0.0473 (16)	0.0625 (19)	0.0629 (18)	0.0087 (14)	−0.0179 (13)	0.0062 (14)
C17	0.091 (2)	0.098 (3)	0.0554 (19)	0.010 (2)	−0.0085 (17)	0.0202 (18)
C18	0.0689 (18)	0.0353 (14)	0.0436 (14)	−0.0102 (13)	−0.0112 (13)	−0.0056 (11)
C19	0.105 (3)	0.0559 (18)	0.0620 (19)	−0.0032 (18)	−0.0383 (18)	−0.0064 (15)

Geometric parameters (Å, º) top

N1—C5	1.375 (3)	C8—H8	0.9300
N1—C1	1.378 (3)	C9—C10	1.365 (4)
N1—H1	0.81 (3)	C9—H9	0.9300
O1—C13	1.348 (3)	C10—C11	1.380 (3)
O1—C16	1.447 (3)	C10—H10	0.9300
O2—C13	1.208 (3)	C11—H11	0.9300
O3—C14	1.333 (3)	C12—H12A	0.9600
O3—C18	1.445 (3)	C12—H12B	0.9600
O4—C14	1.206 (3)	C12—H12C	0.9600
C1—C2	1.349 (3)	C15—H15A	0.9600
C1—C12	1.495 (3)	C15—H15B	0.9600
C2—C13	1.466 (3)	C15—H15C	0.9600
C2—C3	1.522 (3)	C16—C17	1.475 (4)
C3—C4	1.516 (3)	C16—H16A	0.9700
C3—C6	1.533 (3)	C16—H16B	0.9700
C3—H3	0.9800	C17—H17A	0.9600
C4—C5	1.357 (3)	C17—H17B	0.9600
C4—C14	1.464 (3)	C17—H17C	0.9600
C5—C15	1.493 (3)	C18—C19	1.482 (4)
C6—C7	1.378 (3)	C18—H18A	0.9700
C6—C11	1.384 (3)	C18—H18B	0.9700
C7—C8	1.381 (3)	C19—H19A	0.9600
C7—H7	0.9300	C19—H19B	0.9600
C8—C9	1.374 (4)	C19—H19C	0.9600

C5—N1—C1	123.83 (19)	C1—C12—H12B	109.5
C5—N1—H1	116.7 (19)	H12A—C12—H12B	109.5
C1—N1—H1	117.3 (19)	C1—C12—H12C	109.5
C13—O1—C16	117.3 (2)	H12A—C12—H12C	109.5
C14—O3—C18	117.68 (17)	H12B—C12—H12C	109.5
C2—C1—N1	118.6 (2)	O2—C13—O1	121.4 (2)
C2—C1—C12	128.0 (2)	O2—C13—C2	126.6 (2)
N1—C1—C12	113.4 (2)	O1—C13—C2	111.9 (2)
C1—C2—C13	121.2 (2)	O4—C14—O3	121.6 (2)
C1—C2—C3	118.8 (2)	O4—C14—C4	123.6 (2)
C13—C2—C3	119.83 (19)	O3—C14—C4	114.84 (19)
C4—C3—C2	110.05 (17)	C5—C15—H15A	109.5
C4—C3—C6	111.88 (17)	C5—C15—H15B	109.5
C2—C3—C6	109.81 (17)	H15A—C15—H15B	109.5
C4—C3—H3	108.3	C5—C15—H15C	109.5
C2—C3—H3	108.3	H15A—C15—H15C	109.5
C6—C3—H3	108.3	H15B—C15—H15C	109.5
C5—C4—C14	125.3 (2)	O1—C16—C17	112.2 (2)
C5—C4—C3	119.46 (19)	O1—C16—H16A	109.2
C14—C4—C3	115.16 (18)	C17—C16—H16A	109.2
C4—C5—N1	117.9 (2)	O1—C16—H16B	109.2
C4—C5—C15	128.8 (2)	C17—C16—H16B	109.2
N1—C5—C15	113.3 (2)	H16A—C16—H16B	107.9
C7—C6—C11	117.4 (2)	C16—C17—H17A	109.5
C7—C6—C3	120.3 (2)	C16—C17—H17B	109.5
C11—C6—C3	122.23 (19)	H17A—C17—H17B	109.5
C6—C7—C8	121.4 (2)	C16—C17—H17C	109.5
C6—C7—H7	119.3	H17A—C17—H17C	109.5
C8—C7—H7	119.3	H17B—C17—H17C	109.5
C9—C8—C7	120.1 (2)	O3—C18—C19	107.3 (2)
C9—C8—H8	119.9	O3—C18—H18A	110.3
C7—C8—H8	119.9	C19—C18—H18A	110.3
C10—C9—C8	119.5 (2)	O3—C18—H18B	110.3
C10—C9—H9	120.2	C19—C18—H18B	110.3
C8—C9—H9	120.2	H18A—C18—H18B	108.5
C9—C10—C11	120.1 (2)	C18—C19—H19A	109.5
C9—C10—H10	119.9	C18—C19—H19B	109.5
C11—C10—H10	119.9	H19A—C19—H19B	109.5
C10—C11—C6	121.4 (2)	C18—C19—H19C	109.5
C10—C11—H11	119.3	H19A—C19—H19C	109.5
C6—C11—H11	119.3	H19B—C19—H19C	109.5
C1—C12—H12A	109.5

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O4ⁱ	0.81 (3)	2.19 (3)	2.986 (3)	168 (3)
C3—H3···O1	0.98	2.35	2.733 (3)	103
C3—H3···O4	0.98	2.43	2.816 (3)	103
C7—H7···O1	0.93	2.55	3.169 (3)	124
C12—H12C···O2	0.96	2.27	2.841 (3)	116
C15—H15A···O3	0.96	2.42	2.762 (3)	101
C8—H8···O2ⁱⁱ	0.93	2.51	3.387 (3)	157

Symmetry codes: (i) x, y+1, z; (ii) −x+1, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	C₁₉H₂₃NO₄
M_r	329.38
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	9.7502 (12), 7.3854 (9), 24.326 (2)
β (°)	92.567 (1)
V (Å³)	1749.9 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.50 × 0.46 × 0.32

Data collection
Diffractometer	Siemens SMART 1000 CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.958, 0.973
No. of measured, independent and observed [I > 2σ(I)] reflections	8718, 3084, 1989
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.131, 1.01
No. of reflections	3084
No. of parameters	225
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.22, −0.18

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O4ⁱ	0.81 (3)	2.19 (3)	2.986 (3)	168 (3)
C3—H3···O1	0.98	2.35	2.733 (3)	103
C3—H3···O4	0.98	2.43	2.816 (3)	103
C7—H7···O1	0.93	2.55	3.169 (3)	124
C12—H12C···O2	0.96	2.27	2.841 (3)	116
C15—H15A···O3	0.96	2.42	2.762 (3)	101
C8—H8···O2ⁱⁱ	0.93	2.51	3.387 (3)	157

Symmetry codes: (i) x, y+1, z; (ii) −x+1, y−1/2, −z+3/2.

Acknowledgements

The authors acknowledge the support of the Natural Science Foundation of the College of Life Science, Ningxia University (grant No. 081040).

References

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