t-3-Ethyl-r-2,c-6-bis­(4-methoxy­phen­yl)-1-nitro­sopiperidin-4-one

Kavitha, T.; Thenmozhi, M.; Ponnuswamy, S.; Sakthivel, P.; Ponnuswamy, M.N.

doi:10.1107/S1600536809024878

organic compounds

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ISSN: 2056-9890

Volume 65| Part 8| August 2009| Page o1765

doi:10.1107/S1600536809024878

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t-3-Ethyl-r-2,c-6-bis(4-methoxyphenyl)-1-nitrosopiperidin-4-one

T. Kavitha,^a M. Thenmozhi,^a S. Ponnuswamy,^b P. Sakthivel ^b and M. N. Ponnuswamy ^a ^*

^aCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India, and ^bDepartment of Chemistry, Government Arts College (Autonomous), Coimbatore 641 018, Tamilnadu, India
^*Correspondence e-mail: mnpsy2004@yahoo.com

(Received 20 May 2009; accepted 28 June 2009; online 4 July 2009)

In the title molecule, C₂₁H₂₄N₂O₄, the piperidine ring adopts a distorted boat conformation with the ethyl substituent in the axial position. The dihedral angle between the two benzene rings is 70.25 (9)°. An intramolecular C—H⋯O interaction is observed. In the crystal, molecules are linked into a chain along the c axis by C—H⋯O hydrogen bonds and the chains are linked via weak C—H⋯π interactions.

Related literature

For general background to 4-piperidones, see: Wang et al. (1992 ); Grishina et al. (1994 ). For ring conformational analysis, see: Cremer & Pople (1975 ).

Experimental

Crystal data

C₂₁H₂₄N₂O₄
M_r = 368.42
Orthorhombic, P 2₁ 2₁ 2₁
a = 7.2742 (4) Å
b = 15.8459 (7) Å
c = 16.4800 (7) Å
V = 1899.59 (16) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.25 × 0.20 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ) T_min = 0.978, T_max = 0.982
15051 measured reflections
3334 independent reflections
2550 reflections with I > 2σ(I)
R_int = 0.026

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.107
S = 1.02
3334 reflections
244 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15C⋯O1	0.96	2.56	3.163 (4)	121
C18—H18⋯O1ⁱ	0.93	2.56	3.472 (3)	167
C23—H23B⋯Cg1ⁱⁱ	0.96	2.89	3.718 (2)	144
Symmetry codes: (i) $[-x+{\script{5\over 2}}, -y, z+{\script{1\over 2}}]$ ; (ii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]$ . Cg1 is the centroid of the C16–C21 ring.

Data collection: APEX2 (Bruker, 2004 ); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809024878/ci2810sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809024878/ci2810Isup2.hkl

checkCIF report

Comment top

Piperidine derivatives, namely 4-piperidones, are synthetic intermediates in the preparation of various alkaloids and pharmaceutical products (Wang et al., 1992; Grishina et al., 1994).

The piperidine ring adopts a distorted boat conformation, with the ethyl substituent at C3 position in the axial orientation. The puckering parameters for the piperidine ring are q2 = 0.591 (2) Å, q3 = 0.097 (2) Å, Q_T = 0.599 (2) Å and ϕ2 = 73.2 (2)° (Cremer & Pople, 1975). The dihedral angle between the two benzene rings is 70.25 (9)°. The sum of the bond angles around N1 (359°) indicates sp² hybridization. An intramolecular C—H···O interaction is observed.

The crystal structure is stabilized by intermolecular C—H···O hydrogen bonds (Table 1) which link the molecules into a chain along the c axis. The chains are linked via C—H···π interactions involving the C16-C21 ring.

Related literature top

For general background to 4-piperidones, see: Wang et al. (1992); Grishina et al. (1994). For ring conformational analysis, see: Cremer & Pople (1975). Cg1 is the centroid of the C16–C21 ring.

Experimental top

To a solution of t-3-ethyl-r-2,c-6-bis(4-methoxyphenyl)piperidin-4-one (1.69 g, 5 mmol) in chloroform (10 ml) was added conc. HCl (1.5 ml) and water (1.5 ml) and while stirring, solid NaNO₂ (0.84 g,12 mmol) was added in portions during 0.5 h. The solution was stirred at room temperature for another 0.5 h. The organic layer was washed with water, saturated aqueous NaHCO₃ and dried over anhydrous Na₂SO₄. The resulting solution was concentrated and the residue was crystallized from ethanol.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity.
	Fig. 2. The molecular packing of the title compound, viewed approximately along the a axis. Dashed lines indicate hydrogen bonds. H atoms not involved in hydrogen bonding have been omitted.

t-3-Ethyl-r-2,c-6-bis(4-methoxyphenyl)-1-nitrosopiperidin-4-one top

Crystal data top

C₂₁H₂₄N₂O₄	F(000) = 784
M_r = 368.42	D_x = 1.288 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 3334 reflections
a = 7.2742 (4) Å	θ = 2.5–31.8°
b = 15.8459 (7) Å	µ = 0.09 mm⁻¹
c = 16.4800 (7) Å	T = 293 K
V = 1899.59 (16) Å³	Block, colourless
Z = 4	0.25 × 0.20 × 0.20 mm

Data collection top

Bruker Kappa APEXII CCD area-detector diffractometer	3334 independent reflections
Radiation source: fine-focus sealed tube	2550 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.026
ω scans	θ_max = 31.8°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −10→10
T_min = 0.978, T_max = 0.982	k = −23→16
15051 measured reflections	l = −15→24

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.107	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0555P)² + 0.1347P] where P = (F_o² + 2F_c²)/3
3334 reflections	(Δ/σ)_max = 0.001
244 parameters	Δρ_max = 0.20 e Å⁻³
0 restraints	Δρ_min = −0.17 e Å⁻³

Crystal data top

C₂₁H₂₄N₂O₄	V = 1899.59 (16) Å³
M_r = 368.42	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 7.2742 (4) Å	µ = 0.09 mm⁻¹
b = 15.8459 (7) Å	T = 293 K
c = 16.4800 (7) Å	0.25 × 0.20 × 0.20 mm

Data collection top

Bruker Kappa APEXII CCD area-detector diffractometer	3334 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	2550 reflections with I > 2σ(I)
T_min = 0.978, T_max = 0.982	R_int = 0.026
15051 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	0 restraints
wR(F²) = 0.107	H-atom parameters constrained
S = 1.02	Δρ_max = 0.20 e Å⁻³
3334 reflections	Δρ_min = −0.17 e Å⁻³
244 parameters

Special details top

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.

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

	x	y	z	U_iso*/U_eq
O1	1.2631 (2)	0.06968 (12)	0.09708 (10)	0.0722 (5)
O2	0.56881 (19)	0.08201 (12)	0.27581 (11)	0.0648 (4)
O3	1.2829 (2)	−0.26039 (11)	0.42094 (11)	0.0677 (5)
O4	0.96286 (19)	0.17870 (9)	0.59490 (8)	0.0480 (3)
N1	0.82220 (18)	0.02169 (10)	0.24151 (9)	0.0379 (3)
C2	0.9060 (2)	−0.04979 (11)	0.19832 (11)	0.0394 (4)
H2	0.8044	−0.0852	0.1792	0.047*
C3	1.0038 (3)	−0.01651 (12)	0.12220 (12)	0.0431 (4)
H3	1.0693	−0.0633	0.0962	0.052*
C4	1.1403 (3)	0.05176 (12)	0.14271 (12)	0.0439 (4)
C5	1.1176 (2)	0.09628 (12)	0.22290 (12)	0.0406 (4)
H5A	1.1624	0.1536	0.2166	0.049*
H5B	1.1967	0.0686	0.2621	0.049*
C6	0.9234 (2)	0.10068 (11)	0.25901 (11)	0.0361 (4)
H6	0.8583	0.1469	0.2319	0.043*
N7	0.6402 (2)	0.01792 (13)	0.24877 (11)	0.0523 (4)
C8	1.0192 (2)	−0.10403 (10)	0.25549 (12)	0.0383 (4)
C9	1.2088 (3)	−0.11160 (12)	0.25259 (13)	0.0452 (4)
H9	1.2747	−0.0822	0.2134	0.054*
C10	1.3015 (3)	−0.16248 (13)	0.30744 (13)	0.0496 (5)
H10	1.4290	−0.1664	0.3051	0.060*
C11	1.2061 (3)	−0.20718 (12)	0.36542 (13)	0.0484 (5)
C12	1.0155 (3)	−0.20026 (13)	0.36894 (14)	0.0516 (5)
H12	0.9496	−0.2303	0.4077	0.062*
C13	0.9252 (3)	−0.14900 (12)	0.31510 (13)	0.0473 (5)
H13	0.7980	−0.1441	0.3184	0.057*
C16	0.9304 (2)	0.12116 (10)	0.34877 (11)	0.0351 (4)
C17	1.0182 (2)	0.06863 (11)	0.40442 (12)	0.0407 (4)
H17	1.0712	0.0186	0.3865	0.049*
C18	1.0279 (2)	0.08954 (12)	0.48551 (11)	0.0411 (4)
H18	1.0871	0.0537	0.5218	0.049*
C19	0.9491 (2)	0.16428 (11)	0.51316 (11)	0.0373 (4)
C20	0.8647 (3)	0.21793 (12)	0.45857 (11)	0.0415 (4)
H20	0.8142	0.2686	0.4762	0.050*
C21	0.8557 (2)	0.19574 (11)	0.37750 (12)	0.0402 (4)
H21	0.7977	0.2320	0.3412	0.048*
C22	1.4718 (4)	−0.28172 (19)	0.41023 (18)	0.0810 (8)
H22A	1.5095	−0.3196	0.4525	0.122*
H22B	1.5451	−0.2314	0.4125	0.122*
H22C	1.4881	−0.3085	0.3585	0.122*
C23	0.8815 (3)	0.25378 (15)	0.62544 (14)	0.0602 (6)
H23A	0.8998	0.2567	0.6831	0.090*
H23B	0.7521	0.2535	0.6139	0.090*
H23C	0.9375	0.3019	0.6000	0.090*
C14	0.8639 (4)	0.02004 (17)	0.06142 (14)	0.0644 (6)
H14A	0.7562	−0.0160	0.0604	0.077*
H14B	0.8255	0.0753	0.0802	0.077*
C15	0.9381 (5)	0.0281 (2)	−0.02394 (16)	0.0977 (10)
H15A	0.8446	0.0512	−0.0586	0.147*
H15B	0.9737	−0.0265	−0.0436	0.147*
H15C	1.0430	0.0649	−0.0238	0.147*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0685 (10)	0.0868 (12)	0.0614 (10)	−0.0296 (9)	0.0256 (9)	−0.0182 (9)
O2	0.0365 (7)	0.0822 (10)	0.0758 (11)	0.0125 (7)	−0.0027 (7)	−0.0142 (10)
O3	0.0698 (10)	0.0673 (10)	0.0660 (10)	0.0246 (8)	0.0030 (9)	0.0130 (9)
O4	0.0508 (8)	0.0563 (8)	0.0369 (7)	0.0020 (6)	−0.0037 (6)	−0.0045 (6)
N1	0.0286 (6)	0.0435 (7)	0.0416 (8)	−0.0018 (6)	−0.0024 (6)	−0.0043 (7)
C2	0.0366 (8)	0.0379 (8)	0.0436 (10)	−0.0058 (7)	−0.0018 (7)	−0.0076 (8)
C3	0.0489 (10)	0.0419 (8)	0.0386 (10)	−0.0050 (8)	0.0007 (8)	−0.0061 (8)
C4	0.0426 (9)	0.0461 (9)	0.0429 (10)	−0.0062 (8)	0.0033 (8)	−0.0022 (9)
C5	0.0368 (8)	0.0413 (9)	0.0437 (10)	−0.0063 (7)	0.0010 (7)	−0.0054 (8)
C6	0.0340 (7)	0.0357 (8)	0.0384 (10)	0.0006 (6)	−0.0017 (7)	−0.0023 (8)
N7	0.0310 (7)	0.0675 (11)	0.0585 (11)	−0.0007 (8)	−0.0035 (7)	−0.0043 (9)
C8	0.0381 (8)	0.0340 (8)	0.0427 (10)	−0.0032 (6)	0.0031 (7)	−0.0075 (8)
C9	0.0404 (9)	0.0447 (10)	0.0505 (11)	−0.0009 (7)	0.0062 (8)	−0.0027 (9)
C10	0.0394 (9)	0.0521 (10)	0.0574 (13)	0.0091 (8)	0.0038 (9)	−0.0057 (10)
C11	0.0527 (11)	0.0431 (9)	0.0495 (12)	0.0111 (8)	−0.0008 (9)	−0.0020 (10)
C12	0.0532 (11)	0.0494 (10)	0.0521 (12)	−0.0015 (9)	0.0085 (10)	0.0030 (10)
C13	0.0387 (9)	0.0458 (10)	0.0573 (13)	−0.0034 (8)	0.0039 (9)	−0.0017 (10)
C16	0.0296 (7)	0.0377 (8)	0.0381 (9)	0.0008 (6)	−0.0025 (6)	−0.0011 (8)
C17	0.0403 (9)	0.0364 (8)	0.0455 (10)	0.0067 (7)	−0.0038 (8)	−0.0025 (8)
C18	0.0395 (9)	0.0412 (9)	0.0426 (10)	0.0027 (7)	−0.0063 (7)	0.0049 (8)
C19	0.0309 (7)	0.0441 (9)	0.0369 (9)	−0.0032 (7)	−0.0008 (7)	−0.0033 (8)
C20	0.0413 (9)	0.0393 (8)	0.0439 (10)	0.0085 (7)	−0.0012 (8)	−0.0052 (8)
C21	0.0381 (9)	0.0403 (8)	0.0422 (10)	0.0093 (7)	−0.0046 (7)	0.0011 (8)
C22	0.0746 (17)	0.0949 (19)	0.0736 (17)	0.0407 (15)	−0.0056 (14)	0.0020 (16)
C23	0.0586 (12)	0.0756 (14)	0.0465 (12)	0.0077 (11)	0.0004 (10)	−0.0187 (12)
C14	0.0659 (13)	0.0755 (15)	0.0517 (13)	−0.0138 (12)	−0.0142 (11)	0.0046 (12)
C15	0.117 (3)	0.129 (3)	0.0469 (15)	−0.005 (2)	−0.0102 (16)	0.0193 (18)

Geometric parameters (Å, º) top

O1—C4	1.202 (2)	C11—C12	1.392 (3)
O2—N7	1.225 (2)	C12—C13	1.370 (3)
O3—C11	1.364 (3)	C12—H12	0.93
O3—C22	1.426 (3)	C13—H13	0.93
O4—C19	1.370 (2)	C16—C21	1.384 (2)
O4—C23	1.421 (2)	C16—C17	1.394 (2)
N1—N7	1.331 (2)	C17—C18	1.379 (3)
N1—C2	1.470 (2)	C17—H17	0.93
N1—C6	1.481 (2)	C18—C19	1.392 (3)
C2—C8	1.518 (3)	C18—H18	0.93
C2—C3	1.536 (3)	C19—C20	1.382 (3)
C2—H2	0.98	C20—C21	1.383 (3)
C3—C4	1.506 (3)	C20—H20	0.93
C3—C14	1.541 (3)	C21—H21	0.93
C3—H3	0.98	C22—H22A	0.96
C4—C5	1.507 (3)	C22—H22B	0.96
C5—C6	1.535 (2)	C22—H22C	0.96
C5—H5A	0.97	C23—H23A	0.96
C5—H5B	0.97	C23—H23B	0.96
C6—C16	1.515 (3)	C23—H23C	0.96
C6—H6	0.98	C14—C15	1.512 (4)
C8—C9	1.385 (3)	C14—H14A	0.97
C8—C13	1.393 (3)	C14—H14B	0.97
C9—C10	1.386 (3)	C15—H15A	0.96
C9—H9	0.93	C15—H15B	0.96
C10—C11	1.377 (3)	C15—H15C	0.96
C10—H10	0.93

C11—O3—C22	117.3 (2)	C11—C12—H12	120.1
C19—O4—C23	117.23 (16)	C12—C13—C8	121.65 (18)
N7—N1—C2	114.93 (15)	C12—C13—H13	119.2
N7—N1—C6	121.01 (16)	C8—C13—H13	119.2
C2—N1—C6	122.65 (13)	C21—C16—C17	117.70 (17)
N1—C2—C8	111.15 (14)	C21—C16—C6	120.23 (15)
N1—C2—C3	108.85 (14)	C17—C16—C6	122.00 (15)
C8—C2—C3	116.74 (15)	C18—C17—C16	121.19 (16)
N1—C2—H2	106.5	C18—C17—H17	119.4
C8—C2—H2	106.5	C16—C17—H17	119.4
C3—C2—H2	106.5	C17—C18—C19	120.04 (17)
C4—C3—C2	111.62 (15)	C17—C18—H18	120.0
C4—C3—C14	108.13 (17)	C19—C18—H18	120.0
C2—C3—C14	110.74 (17)	O4—C19—C20	124.75 (17)
C4—C3—H3	108.8	O4—C19—C18	115.70 (16)
C2—C3—H3	108.8	C20—C19—C18	119.55 (17)
C14—C3—H3	108.8	C19—C20—C21	119.58 (16)
O1—C4—C3	121.27 (18)	C19—C20—H20	120.2
O1—C4—C5	121.28 (17)	C21—C20—H20	120.2
C3—C4—C5	117.44 (16)	C20—C21—C16	121.92 (17)
C4—C5—C6	117.51 (15)	C20—C21—H21	119.0
C4—C5—H5A	107.9	C16—C21—H21	119.0
C6—C5—H5A	107.9	O3—C22—H22A	109.5
C4—C5—H5B	107.9	O3—C22—H22B	109.5
C6—C5—H5B	107.9	H22A—C22—H22B	109.5
H5A—C5—H5B	107.2	O3—C22—H22C	109.5
N1—C6—C16	112.83 (15)	H22A—C22—H22C	109.5
N1—C6—C5	110.11 (14)	H22B—C22—H22C	109.5
C16—C6—C5	110.94 (14)	O4—C23—H23A	109.5
N1—C6—H6	107.6	O4—C23—H23B	109.5
C16—C6—H6	107.6	H23A—C23—H23B	109.5
C5—C6—H6	107.6	O4—C23—H23C	109.5
O2—N7—N1	114.66 (17)	H23A—C23—H23C	109.5
C9—C8—C13	117.96 (18)	H23B—C23—H23C	109.5
C9—C8—C2	124.60 (17)	C15—C14—C3	113.7 (2)
C13—C8—C2	117.44 (16)	C15—C14—H14A	108.8
C8—C9—C10	120.83 (19)	C3—C14—H14A	108.8
C8—C9—H9	119.6	C15—C14—H14B	108.8
C10—C9—H9	119.6	C3—C14—H14B	108.8
C11—C10—C9	120.40 (18)	H14A—C14—H14B	107.7
C11—C10—H10	119.8	C14—C15—H15A	109.5
C9—C10—H10	119.8	C14—C15—H15B	109.5
O3—C11—C10	125.24 (18)	H15A—C15—H15B	109.5
O3—C11—C12	115.4 (2)	C14—C15—H15C	109.5
C10—C11—C12	119.37 (19)	H15A—C15—H15C	109.5
C13—C12—C11	119.8 (2)	H15B—C15—H15C	109.5
C13—C12—H12	120.1

N7—N1—C2—C8	−111.25 (18)	C8—C9—C10—C11	0.7 (3)
C6—N1—C2—C8	82.2 (2)	C22—O3—C11—C10	−10.4 (3)
N7—N1—C2—C3	118.82 (18)	C22—O3—C11—C12	168.6 (2)
C6—N1—C2—C3	−47.7 (2)	C9—C10—C11—O3	178.42 (19)
N1—C2—C3—C4	54.76 (19)	C9—C10—C11—C12	−0.6 (3)
C8—C2—C3—C4	−72.04 (19)	O3—C11—C12—C13	−179.33 (18)
N1—C2—C3—C14	−65.78 (19)	C10—C11—C12—C13	−0.2 (3)
C8—C2—C3—C14	167.43 (16)	C11—C12—C13—C8	1.0 (3)
C2—C3—C4—O1	159.7 (2)	C9—C8—C13—C12	−0.9 (3)
C14—C3—C4—O1	−78.2 (3)	C2—C8—C13—C12	179.36 (17)
C2—C3—C4—C5	−19.8 (2)	N1—C6—C16—C21	−119.97 (17)
C14—C3—C4—C5	102.2 (2)	C5—C6—C16—C21	115.94 (18)
O1—C4—C5—C6	153.2 (2)	N1—C6—C16—C17	63.0 (2)
C3—C4—C5—C6	−27.2 (2)	C5—C6—C16—C17	−61.1 (2)
N7—N1—C6—C16	72.0 (2)	C21—C16—C17—C18	1.0 (3)
C2—N1—C6—C16	−122.28 (17)	C6—C16—C17—C18	178.05 (17)
N7—N1—C6—C5	−163.49 (17)	C16—C17—C18—C19	0.0 (3)
C2—N1—C6—C5	2.3 (2)	C23—O4—C19—C20	1.0 (3)
C4—C5—C6—N1	36.3 (2)	C23—O4—C19—C18	−179.06 (16)
C4—C5—C6—C16	161.94 (15)	C17—C18—C19—O4	178.80 (17)
C2—N1—N7—O2	−171.53 (17)	C17—C18—C19—C20	−1.3 (3)
C6—N1—N7—O2	−4.7 (3)	O4—C19—C20—C21	−178.57 (18)
N1—C2—C8—C9	−112.31 (19)	C18—C19—C20—C21	1.5 (3)
C3—C2—C8—C9	13.3 (3)	C19—C20—C21—C16	−0.5 (3)
N1—C2—C8—C13	67.46 (19)	C17—C16—C21—C20	−0.7 (3)
C3—C2—C8—C13	−166.89 (16)	C6—C16—C21—C20	−177.86 (17)
C13—C8—C9—C10	0.0 (3)	C4—C3—C14—C15	75.9 (3)
C2—C8—C9—C10	179.80 (17)	C2—C3—C14—C15	−161.5 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15C···O1	0.96	2.56	3.163 (4)	121
C18—H18···O1ⁱ	0.93	2.56	3.472 (3)	167
C23—H23B···Cg1ⁱⁱ	0.96	2.89	3.718 (2)	144

Symmetry codes: (i) −x+5/2, −y, z+1/2; (ii) x−1/2, −y+1/2, −z+1.

Experimental details

Crystal data
Chemical formula	C₂₁H₂₄N₂O₄
M_r	368.42
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	293
a, b, c (Å)	7.2742 (4), 15.8459 (7), 16.4800 (7)
V (Å³)	1899.59 (16)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.25 × 0.20 × 0.20

Data collection
Diffractometer	Bruker Kappa APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2001)
T_min, T_max	0.978, 0.982
No. of measured, independent and observed [I > 2σ(I)] reflections	15051, 3334, 2550
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.741

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.107, 1.02
No. of reflections	3334
No. of parameters	244
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.20, −0.17

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15C···O1	0.96	2.56	3.163 (4)	121
C18—H18···O1ⁱ	0.93	2.56	3.472 (3)	167
C23—H23B···Cg1ⁱⁱ	0.96	2.89	3.718 (2)	144

Symmetry codes: (i) −x+5/2, −y, z+1/2; (ii) x−1/2, −y+1/2, −z+1.

Acknowledgements

TK thanks Dr Babu Varghese, SAIF, IIT-Madras, Chennai, India, for his help with the data collection. SP thanks the UGC, India, for financial support.

References

Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Grishina, G. V., Gaidarova, E. L. & Zefirov, N. S. (1994). Chem. Heterocycl. Compd, 30, 1401–1426. CrossRef Google Scholar
Sheldrick, G. M. (2001). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wang, C.-L. & Wuorola, M. A. (1992). Org. Prep. Proceed. Int. 24, 585–621. Google Scholar