(S)-1,5-Dibenzyl-3-tert-butyl­imidazol­idin-4-one

Zheng, J.-F.; Guo, J.-N.; Huang, S.-Y.; Teng, B.; Jin, L.-R.

doi:10.1107/S1600536808018461

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 7| July 2008| Page o1330

doi:10.1107/S1600536808018461

Open

access

(S)-1,5-Dibenzyl-3-tert-butylimidazolidin-4-one

Jian-Feng Zheng,^a ^* Jian-Nan Guo,^a Su-Yu Huang,^a Bo Teng ^a and Li-Ren Jin ^a

^aDepartment of Chemistry, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
^*Correspondence e-mail: zjf485@xmu.edu.cn

(Received 11 June 2008; accepted 18 June 2008; online 25 June 2008)

The title compound, C₂₁H₂₆N₂O, was obtained as an unexpected by-product when attempting to prepare (S)-2-benzyl-N-tert-butyl-1,2,3,4-tetrahydroisoquinoline-3-carboxamide from (S)-2-benzylamino-N-tert-butyl-3-phenylpropanamide and dimethoxymethane. The molecules are linked by weak C—H⋯O hydrogen bonds, generating linear chains parallel to the b axis. C—H⋯π interactions provide further stability for the crystal structure. The planes of the two phenyl rings make a dihedral angle of 84.1 (1)°. The absolute configuration was known from the starting material.

Related literature

For related literature, see: Allen et al. (1987 ); Pavel et al. (1993 ); Jin et al. 2005 .

Experimental

Crystal data

C₂₁H₂₆N₂O
M_r = 322.44
Orthorhombic, P 2₁ 2₁ 2₁
a = 9.4112 (6) Å
b = 11.4713 (7) Å
c = 17.0556 (11) Å
V = 1841.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 173 (2) K
0.62 × 0.45 × 0.23 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.957, T_max = 0.984
8034 measured reflections
2047 independent reflections
1824 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.042
wR(F²) = 0.107
S = 1.00
2047 reflections
217 parameters
H-atom parameters constrained
Δρ_max = 0.34 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
C6—H6A⋯O4ⁱ	0.99	2.48	3.439 (4)	164
C17—H17⋯Cgⁱⁱ	0.95	2.68	3.621 (4)	169
Symmetry codes: (i) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[-x+{\script{1\over 2}}, -y, z-{\script{1\over 2}}]$ . Cg is the centroid of the C7–C12 phenyl ring.

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808018461/bt2725sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808018461/bt2725Isup2.hkl

checkCIF report

Comment top

In our studies on the synthesis of (S)—N-tert-butyl-tetrahydroisoquinoline- 3-carboxamide, a key intermediate for the synthesis of Nelfinavir and Saquinavir, two of the most clinically efficacious anti-AIDS drugs, we attempted to prepare (S)-2-benzyl-N-tert-butyl-1,2,3,4-tetrahydroisoquinoline- 3-carboxamide from (S)-2-(benzylamino)-N-tert-butyl-3 -phenylpropanamide and dimethoxymethane. During this experiment, the title compound, (I), was isolated unexpectedly.

The two planes of phenyl rings make a dihedral angle of 84.1 (1)° (Fig. 1). The absolute configuration (S) of the stereocentre C5 remains unchanged during the synthetic procedure. An X-ray crystal structure determination of the molecular structure of compound (I) was carried out to determine its conformation. The bond lengths are within normal ranges (Allen et al., 1987).

The packing is shown in Fig. 2. The occurrence of weak C—H···O hydrogen bond interactions leads to the formation of linear chains parallel to the b axis. The packing is further stabilized by C—H···π interactions (Fig. 2) with typical geometry (Pavel et al., 1993).

Related literature top

For related literature, see: Allen et al. (1987); Pavel et al. (1993); Jin et al. 2005.Cg is the centroid of the C7–C12 phenyl ring.

Experimental top

The title compound was prepared by a method based on one described by Jin et al. (2005). To a solution of (S)-2-(benzylamino)-N-tert-butyl- 3-phenylpropanamide (11.8 g, 38.1 mmol) in dichloromethane (400 ml) was added dropwise boron trifluoride etherate (13.5 ml, 79.6 mmol) and dimethoxymethane (6.02 g, 79.1 mmol). The mixture was heated to reflux for 48 h. The reaction was quenched by addition of water (90 ml). The solution was adjusted to pH 8 with a 27% aqueous ammonia solution. The organic layer was separated, and the aqueous phase was extracted with dichloromethane. The combined organic phases were washed with brine and dried over Na₂SO₄. After filtration and evaporation of the solvents under reduced pressure, the residue was flash chromatographic purification on silica gel (ethyl acetate / petroleum ether = 1 / 4) yielded the product as a white solid. Single crystals were obtained by slow evaporation of a mixture of petroleum ether / dichloromethane solution.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of (I) with the atom-labeling scheme, showing 50% probability displacement ellipsoids. H atoms are drawn as spheres of arbitrary radius.
	Fig. 2. The packing of the molecules, viewed down the a axis. C—H···π and hydrogen bonds interactions are shown as dashed lines. Cg is the centroid of the C7 / C12 phenyl ring.

(S)-1,5-Dibenzyl-3-tert-butylimidazolidin-4-one top

Crystal data top

C₂₁H₂₆N₂O	F(000) = 696
M_r = 322.44	D_x = 1.163 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5367 reflections
a = 9.4112 (6) Å	θ = 2.8–32.4°
b = 11.4713 (7) Å	µ = 0.07 mm⁻¹
c = 17.0556 (11) Å	T = 173 K
V = 1841.3 (2) Å³	Block, colorless
Z = 4	0.62 × 0.45 × 0.23 mm

Data collection top

Bruker APEX CCD diffractometer	2047 independent reflections
Radiation source: fine-focus sealed tube	1824 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
Detector resolution: 16.1903 pixels mm^-1	θ_max = 26.0°, θ_min = 2.8°
ϕ and ω scans	h = −11→11
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −11→14
T_min = 0.957, T_max = 0.984	l = −20→21
8034 measured reflections

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.107	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.0673P)² + 0.3582P] where P = (F_o² + 2F_c²)/3
2047 reflections	(Δ/σ)_max < 0.001
217 parameters	Δρ_max = 0.34 e Å⁻³
0 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₂₁H₂₆N₂O	V = 1841.3 (2) Å³
M_r = 322.44	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 9.4112 (6) Å	µ = 0.07 mm⁻¹
b = 11.4713 (7) Å	T = 173 K
c = 17.0556 (11) Å	0.62 × 0.45 × 0.23 mm

Data collection top

Bruker APEX CCD diffractometer	2047 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	1824 reflections with I > 2σ(I)
T_min = 0.957, T_max = 0.984	R_int = 0.023
8034 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.042	0 restraints
wR(F²) = 0.107	H-atom parameters constrained
S = 1.00	Δρ_max = 0.34 e Å⁻³
2047 reflections	Δρ_min = −0.18 e Å⁻³
217 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
N1	0.3052 (2)	0.09221 (18)	0.72137 (12)	0.0250 (5)
C2	0.3096 (3)	0.0518 (2)	0.80219 (15)	0.0286 (6)
H2A	0.3427	−0.0300	0.8054	0.034*
H2B	0.2152	0.0581	0.8274	0.034*
N3	0.4114 (2)	0.1312 (2)	0.83816 (13)	0.0310 (5)
O4	0.6042 (2)	0.2352 (2)	0.79357 (14)	0.0554 (7)
C4	0.4998 (3)	0.1736 (2)	0.78380 (18)	0.0343 (6)
C5	0.4499 (3)	0.1293 (2)	0.70449 (16)	0.0296 (6)
H5	0.5077	0.0596	0.6896	0.036*
C6	0.2517 (3)	0.0043 (2)	0.66686 (16)	0.0302 (6)
H6A	0.3094	−0.0674	0.6719	0.036*
H6B	0.2620	0.0334	0.6125	0.036*
C7	0.0978 (3)	−0.0245 (2)	0.68211 (14)	0.0273 (6)
C8	0.0523 (3)	−0.1392 (2)	0.68251 (17)	0.0337 (6)
H8	0.1188	−0.2004	0.6745	0.040*
C9	−0.0903 (3)	−0.1651 (3)	0.69453 (19)	0.0424 (7)
H9	−0.1208	−0.2441	0.6940	0.051*
C10	−0.1867 (3)	−0.0786 (3)	0.7070 (2)	0.0443 (8)
H10	−0.2840	−0.0971	0.7153	0.053*
C11	−0.1422 (3)	0.0367 (3)	0.7075 (2)	0.0458 (8)
H11	−0.2087	0.0975	0.7166	0.055*
C12	−0.0008 (3)	0.0628 (2)	0.69456 (18)	0.0362 (7)
H12	0.0291	0.1419	0.6942	0.043*
C13	0.4632 (4)	0.2208 (3)	0.64056 (17)	0.0399 (7)
H13A	0.3822	0.2753	0.6457	0.048*
H13B	0.5510	0.2660	0.6504	0.048*
C14	0.4673 (3)	0.1777 (2)	0.55702 (17)	0.0326 (6)
C15	0.3770 (4)	0.2246 (3)	0.5011 (2)	0.0469 (8)
H15	0.3086	0.2813	0.5161	0.056*
C16	0.3856 (4)	0.1894 (3)	0.4231 (2)	0.0553 (10)
H16	0.3238	0.2229	0.3853	0.066*
C17	0.4815 (4)	0.1078 (3)	0.40063 (19)	0.0508 (9)
H17	0.4882	0.0852	0.3472	0.061*
C18	0.5691 (3)	0.0578 (3)	0.45596 (19)	0.0476 (8)
H18	0.6343	−0.0013	0.4409	0.057*
C19	0.5622 (3)	0.0934 (3)	0.53324 (18)	0.0399 (7)
H19	0.6242	0.0591	0.5707	0.048*
C20	0.4334 (3)	0.1408 (3)	0.92442 (17)	0.0382 (7)
C21	0.5676 (6)	0.0773 (5)	0.9454 (3)	0.0904 (15)
H21A	0.5591	−0.0048	0.9301	0.109*
H21B	0.5835	0.0825	1.0020	0.109*
H21C	0.6478	0.1127	0.9176	0.109*
C22	0.3043 (5)	0.0931 (5)	0.9661 (2)	0.0855 (14)
H22A	0.2931	0.0102	0.9535	0.103*
H22B	0.2197	0.1359	0.9490	0.103*
H22C	0.3163	0.1022	1.0229	0.103*
C23	0.4439 (5)	0.2670 (3)	0.9470 (2)	0.0604 (10)
H23A	0.5271	0.3019	0.9216	0.091*
H23B	0.4536	0.2735	1.0040	0.091*
H23C	0.3579	0.3081	0.9300	0.091*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0249 (10)	0.0266 (10)	0.0235 (11)	−0.0031 (9)	0.0000 (9)	−0.0017 (9)
C2	0.0307 (13)	0.0274 (12)	0.0277 (13)	−0.0071 (11)	−0.0031 (11)	0.0001 (11)
N3	0.0279 (11)	0.0358 (12)	0.0293 (12)	−0.0077 (10)	−0.0043 (9)	−0.0024 (10)
O4	0.0406 (12)	0.0721 (16)	0.0535 (14)	−0.0296 (12)	0.0094 (11)	−0.0233 (12)
C4	0.0277 (12)	0.0354 (14)	0.0397 (15)	−0.0057 (12)	0.0037 (13)	−0.0089 (12)
C5	0.0281 (13)	0.0283 (12)	0.0324 (14)	−0.0034 (11)	0.0060 (12)	−0.0057 (11)
C6	0.0331 (13)	0.0300 (13)	0.0275 (13)	−0.0049 (12)	0.0008 (11)	−0.0073 (11)
C7	0.0325 (14)	0.0295 (12)	0.0198 (11)	−0.0056 (11)	−0.0042 (11)	0.0003 (10)
C8	0.0406 (15)	0.0293 (13)	0.0314 (14)	−0.0049 (12)	−0.0028 (12)	0.0004 (12)
C9	0.0476 (17)	0.0374 (15)	0.0422 (17)	−0.0168 (14)	−0.0120 (14)	0.0079 (13)
C10	0.0304 (14)	0.0547 (19)	0.0479 (18)	−0.0117 (14)	−0.0080 (14)	0.0090 (15)
C11	0.0316 (15)	0.0472 (18)	0.059 (2)	0.0009 (13)	−0.0099 (15)	0.0036 (16)
C12	0.0336 (14)	0.0299 (13)	0.0450 (16)	−0.0025 (12)	−0.0067 (13)	−0.0008 (13)
C13	0.0526 (18)	0.0293 (13)	0.0378 (17)	−0.0078 (14)	0.0140 (14)	−0.0011 (12)
C14	0.0351 (14)	0.0285 (13)	0.0342 (15)	−0.0089 (12)	0.0063 (12)	0.0038 (11)
C15	0.0500 (19)	0.0334 (16)	0.057 (2)	0.0005 (15)	−0.0022 (16)	0.0135 (16)
C16	0.059 (2)	0.060 (2)	0.047 (2)	−0.0115 (19)	−0.0159 (18)	0.0226 (17)
C17	0.052 (2)	0.067 (2)	0.0334 (16)	−0.0305 (19)	0.0027 (15)	0.0044 (15)
C18	0.0399 (17)	0.061 (2)	0.0414 (17)	−0.0065 (16)	0.0117 (15)	−0.0079 (16)
C19	0.0341 (15)	0.0501 (17)	0.0355 (16)	−0.0011 (14)	0.0020 (13)	0.0011 (14)
C20	0.0396 (15)	0.0439 (17)	0.0311 (15)	−0.0076 (14)	−0.0108 (12)	0.0003 (13)
C21	0.103 (3)	0.095 (3)	0.073 (3)	0.036 (3)	−0.038 (2)	−0.012 (2)
C22	0.098 (3)	0.120 (3)	0.0391 (18)	−0.052 (3)	−0.003 (2)	−0.001 (2)
C23	0.084 (3)	0.058 (2)	0.0385 (19)	−0.011 (2)	0.003 (2)	−0.0113 (16)

Geometric parameters (Å, º) top

N1—C2	1.455 (3)	C13—C14	1.508 (4)
N1—C5	1.455 (3)	C13—H13A	0.9900
N1—C6	1.461 (3)	C13—H13B	0.9900
C2—N3	1.457 (3)	C14—C19	1.378 (4)
C2—H2A	0.9900	C14—C15	1.387 (4)
C2—H2B	0.9900	C15—C16	1.392 (5)
N3—C4	1.336 (4)	C15—H15	0.9500
N3—C20	1.490 (4)	C16—C17	1.355 (5)
O4—C4	1.222 (3)	C16—H16	0.9500
C4—C5	1.519 (4)	C17—C18	1.378 (5)
C5—C13	1.519 (4)	C17—H17	0.9500
C5—H5	1.0000	C18—C19	1.381 (5)
C6—C7	1.508 (4)	C18—H18	0.9500
C6—H6A	0.9900	C19—H19	0.9500
C6—H6B	0.9900	C20—C21	1.501 (5)
C7—C12	1.381 (4)	C20—C23	1.502 (5)
C7—C8	1.384 (4)	C20—C22	1.510 (5)
C8—C9	1.390 (4)	C21—H21A	0.9800
C8—H8	0.9500	C21—H21B	0.9800
C9—C10	1.362 (4)	C21—H21C	0.9800
C9—H9	0.9500	C22—H22A	0.9800
C10—C11	1.388 (5)	C22—H22B	0.9800
C10—H10	0.9500	C22—H22C	0.9800
C11—C12	1.382 (4)	C23—H23A	0.9800
C11—H11	0.9500	C23—H23B	0.9800
C12—H12	0.9500	C23—H23C	0.9800

C2—N1—C5	104.7 (2)	C5—C13—H13A	108.0
C2—N1—C6	113.1 (2)	C14—C13—H13B	108.0
C5—N1—C6	113.5 (2)	C5—C13—H13B	108.0
N1—C2—N3	102.62 (19)	H13A—C13—H13B	107.3
N1—C2—H2A	111.2	C19—C14—C15	117.9 (3)
N3—C2—H2A	111.2	C19—C14—C13	121.6 (3)
N1—C2—H2B	111.2	C15—C14—C13	120.5 (3)
N3—C2—H2B	111.2	C14—C15—C16	120.6 (3)
H2A—C2—H2B	109.2	C14—C15—H15	119.7
C4—N3—C2	110.1 (2)	C16—C15—H15	119.7
C4—N3—C20	124.9 (2)	C17—C16—C15	120.7 (3)
C2—N3—C20	123.6 (2)	C17—C16—H16	119.7
O4—C4—N3	128.0 (3)	C15—C16—H16	119.7
O4—C4—C5	124.3 (3)	C16—C17—C18	119.4 (3)
N3—C4—C5	107.7 (2)	C16—C17—H17	120.3
N1—C5—C13	114.9 (2)	C18—C17—H17	120.3
N1—C5—C4	102.2 (2)	C17—C18—C19	120.2 (3)
C13—C5—C4	112.5 (2)	C17—C18—H18	119.9
N1—C5—H5	109.0	C19—C18—H18	119.9
C13—C5—H5	109.0	C14—C19—C18	121.2 (3)
C4—C5—H5	109.0	C14—C19—H19	119.4
N1—C6—C7	111.9 (2)	C18—C19—H19	119.4
N1—C6—H6A	109.2	N3—C20—C21	108.4 (3)
C7—C6—H6A	109.2	N3—C20—C23	109.5 (3)
N1—C6—H6B	109.2	C21—C20—C23	110.6 (3)
C7—C6—H6B	109.2	N3—C20—C22	109.1 (3)
H6A—C6—H6B	107.9	C21—C20—C22	112.9 (4)
C12—C7—C8	118.7 (3)	C23—C20—C22	106.4 (3)
C12—C7—C6	120.9 (2)	C20—C21—H21A	109.5
C8—C7—C6	120.4 (3)	C20—C21—H21B	109.5
C7—C8—C9	120.2 (3)	H21A—C21—H21B	109.5
C7—C8—H8	119.9	C20—C21—H21C	109.4
C9—C8—H8	119.9	H21A—C21—H21C	109.5
C10—C9—C8	120.7 (3)	H21B—C21—H21C	109.5
C10—C9—H9	119.6	C20—C22—H22A	109.5
C8—C9—H9	119.6	C20—C22—H22B	109.4
C9—C10—C11	119.6 (3)	H22A—C22—H22B	109.5
C9—C10—H10	120.2	C20—C22—H22C	109.5
C11—C10—H10	120.2	H22A—C22—H22C	109.5
C12—C11—C10	119.8 (3)	H22B—C22—H22C	109.5
C12—C11—H11	120.1	C20—C23—H23A	109.5
C10—C11—H11	120.1	C20—C23—H23B	109.5
C7—C12—C11	121.0 (3)	H23A—C23—H23B	109.5
C7—C12—H12	119.5	C20—C23—H23C	109.5
C11—C12—H12	119.5	H23A—C23—H23C	109.5
C14—C13—C5	117.0 (2)	H23B—C23—H23C	109.5
C14—C13—H13A	108.0

C5—N1—C2—N3	35.3 (3)	C8—C9—C10—C11	0.2 (5)
C6—N1—C2—N3	159.4 (2)	C9—C10—C11—C12	0.6 (5)
N1—C2—N3—C4	−25.0 (3)	C8—C7—C12—C11	0.2 (4)
N1—C2—N3—C20	168.0 (2)	C6—C7—C12—C11	179.1 (3)
C2—N3—C4—O4	−174.1 (3)	C10—C11—C12—C7	−0.8 (5)
C20—N3—C4—O4	−7.3 (5)	N1—C5—C13—C14	−84.6 (3)
C2—N3—C4—C5	4.8 (3)	C4—C5—C13—C14	159.1 (3)
C20—N3—C4—C5	171.5 (3)	C5—C13—C14—C19	−52.8 (4)
C2—N1—C5—C13	−154.4 (2)	C5—C13—C14—C15	128.8 (3)
C6—N1—C5—C13	81.8 (3)	C19—C14—C15—C16	−1.8 (5)
C2—N1—C5—C4	−32.3 (3)	C13—C14—C15—C16	176.6 (3)
C6—N1—C5—C4	−156.1 (2)	C14—C15—C16—C17	0.7 (5)
O4—C4—C5—N1	−163.8 (3)	C15—C16—C17—C18	1.2 (5)
N3—C4—C5—N1	17.3 (3)	C16—C17—C18—C19	−2.0 (5)
O4—C4—C5—C13	−40.1 (4)	C15—C14—C19—C18	1.0 (4)
N3—C4—C5—C13	141.0 (2)	C13—C14—C19—C18	−177.4 (3)
C2—N1—C6—C7	65.6 (3)	C17—C18—C19—C14	0.9 (5)
C5—N1—C6—C7	−175.3 (2)	C4—N3—C20—C21	−62.2 (4)
N1—C6—C7—C12	45.6 (3)	C2—N3—C20—C21	102.8 (4)
N1—C6—C7—C8	−135.5 (3)	C4—N3—C20—C23	58.5 (4)
C12—C7—C8—C9	0.6 (4)	C2—N3—C20—C23	−136.5 (3)
C6—C7—C8—C9	−178.3 (3)	C4—N3—C20—C22	174.5 (3)
C7—C8—C9—C10	−0.8 (5)	C2—N3—C20—C22	−20.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6A···O4ⁱ	0.99	2.48	3.439 (4)	164
C17—H17···Cgⁱⁱ	0.95	2.68	3.621 (4)	169

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

Experimental details

Crystal data
Chemical formula	C₂₁H₂₆N₂O
M_r	322.44
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	173
a, b, c (Å)	9.4112 (6), 11.4713 (7), 17.0556 (11)
V (Å³)	1841.3 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.62 × 0.45 × 0.23

Data collection
Diffractometer	Bruker APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.957, 0.984
No. of measured, independent and observed [I > 2σ(I)] reflections	8034, 2047, 1824
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.042, 0.107, 1.00
No. of reflections	2047
No. of parameters	217
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.34, −0.18

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPIII (Farrugia, 1997).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6A···O4ⁱ	0.99	2.48	3.439 (4)	163.9
C17—H17···Cgⁱⁱ	0.95	2.68	3.621 (4)	169.4

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

Acknowledgements

The authors acknowledge the Natural Science Foundation of Fujian Province of China (No. U0650024), Xiamen Science Foundation (No.3502Z20055019) and NFFTBS (No. J0630429) for financial support. We also thank Mr Z.-B. Wei and Mr T.-B. Wen for technical assistance.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Bruker (2001). SAINT, SMART and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Jin, L. R., Huang, S. J. & Zhang, F. J. (2005). China Patent 1 562 974. Google Scholar
Pavel, H., Heinrich, L. S. & Edward, W. S. (1993). J. Am. Chem. Soc. 116, 3500–3506. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar