Methyl 2-acetamido-2-(4-hy­droxy-2-methyl-1,3-dioxo-1,2,3,4-tetra­hydro­isoquinolin-4-yl)-4-methyl­penta­noate

Fun, H.-K.; Quah, C.K.; Xu, K.; Zhang, Y.

doi:10.1107/S1600536811022999

organic compounds

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ISSN: 2056-9890

Volume 67| Part 7| July 2011| Pages o1710-o1711

doi:10.1107/S1600536811022999

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Methyl 2-acetamido-2-(4-hydroxy-2-methyl-1,3-dioxo-1,2,3,4-tetrahydroisoquinolin-4-yl)-4-methylpentanoate

Hoong-Kun Fun,^a ^*‡ Ching Kheng Quah,^a § Kai Xu ^b and Yan Zhang ^b

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bSchool of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, People's Republic of China
^*Correspondence e-mail: hkfun@usm.my

(Received 30 May 2011; accepted 14 June 2011; online 18 June 2011)

In the isoquinoline ring system of the title molecule, C₁₉H₂₄N₂O₆, the N-heterocyclic ring is in a half-boat conformation. The molecular structure is stabilized by an intramolecular O—H⋯O hydrogen bond, which generates an S(7) ring motif. In the crystal, molecules are linked via intermolecular bifurcated N—H⋯(O,O) and weak C—H⋯O hydrogen bonds into a three-dimensional network.

Related literature

For general background to and the potential biological activity of title compound, see: Yu et al. (2010 ); Huang et al. (2011 ); Rao et al. (1995 ); Nagamitsu et al. (1996 ); Evans & Weber (1986 ); Heimgartner (1991 ); Rando (1975 ); Griesbeck et al. (2003 ); Zhang et al. (2004 ); Wang et al. (2010 ). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ). For standard bond-length data, see: Allen et al. (1987 ). For ring conformations, see: Cremer & Pople (1975 ). For related structures, see: Fun et al. (2011a ,b ,c ,d ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₁₉H₂₄N₂O₆
M_r = 376.40
Monoclinic, C c
a = 17.8256 (15) Å
b = 8.7584 (6) Å
c = 11.9182 (8) Å
β = 100.404 (5)°
V = 1830.1 (2) Å³
Z = 4
Cu Kα radiation
μ = 0.85 mm⁻¹
T = 100 K
0.50 × 0.15 × 0.15 mm

Data collection

Bruker APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.678, T_max = 0.883
18268 measured reflections
2713 independent reflections
2673 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.024
wR(F²) = 0.059
S = 1.05
2713 reflections
257 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.11 e Å⁻³
Δρ_min = −0.14 e Å⁻³
Absolute structure: Flack (1983 ), 1204 Friedel pairs
Flack parameter: 0.05 (13)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H1N2⋯O1ⁱ	0.92 (2)	2.511 (19)	3.3431 (17)	150.3 (15)
N2—H1N2⋯O3ⁱ	0.92 (2)	2.44 (2)	3.1675 (18)	135.6 (16)
O3—H1O3⋯O6	0.86 (2)	1.83 (2)	2.6543 (16)	160 (2)
C5—H5A⋯O6ⁱⁱ	0.93	2.59	3.469 (2)	157
Symmetry codes: (i) $[x, -y+1, z-{\script{1\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, y-{\script{1\over 2}}, z]$ .

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811022999/lh5262sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811022999/lh5262Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811022999/lh5262Isup3.cml

checkCIF report

Comment top

Photocycloaddition of isoquinoline-1,3,4-trione combined with following transformation of the photocycloadducts has become facile method to build various scaffold containing an isoquinoline moiety (Yu et al., 2010; Huang et al., 2011). β-Hydroxy-amino acids are important building blocks to constitute more complex natural products. β-Hydroxy tyrosine and β-hydroxy phenylalanine derivatives are found in the clinically important antibiotic glycopeptides vancomycin, β-hydroxy leucine is found in (+)-lactacystin, and E-2-butenyl-4,N-dimethyl-l-threonine is an essential part of cyclosporine (Rao et al., 1995; Nagamitsu et al., 1996; Evans et al., 1986). α,α-Disubstituted amino acids represent a highly interesting class of non-proteinogenic amino acids, especially in view of their potential activity as enzyme inhibitors (Heimgartner, 1991; Rando, 1975). Many bioactive natural products contain β-hydroxy-amino acid or α,α-disubstituted amino acid and there has been intense interest to develop methodology to construct such moieties using photocycloadducts of oxazoles (Griesbeck et al., 2003; Zhang et al., 2004; Wang et al., 2010). The title compound was derived from photocycloadducts of isoquinoline-1,3,4-trione and oxazoles. Due to the importance of β-hydroxy-amino acid derivatives, we report in this paper the crystal structure of the title compound.

In the title racemic compound, Fig. 1, the isoquinoline ring system (N1/C1-C9) is not completely planar, the N-heterocyclic ring (N1/C1-C3/C8/C9) being distorted towards a half-boat conformation with atom C9 deviating by 0.201 (2) Å from the mean plane through the remaining atoms, puckering parameters (Cremer & Pople, 1975) Q = 0.3038 (17) Å, Θ = 70.1 (3)° and ϕ = 110.6 (3)°. Bond lengths (Allen et al., 1987) and angles are within normal ranges and comparable to related structures (Fun et al., 2011a,b,c,d). The molecular structure is stabilized by an intramolecular O3–H1O3···O6 hydrogen bond (Table 1) which generates a S(7) ring motif (Fig. 1, Bernstein et al., 1995).

In the crystal structure, Fig. 2, molecules are linked via intermolecular N2–H1N2···O1ⁱ, N2–H1N2···O3ⁱ and weak C5–H5A···O6ⁱⁱ hydrogen bonds (Table 1) into a three-dimensional network.

Related literature top

For general background to and the potential biological activity of title compound, see: Yu et al. (2010); Huang et al. (2011); Rao et al. (1995); Nagamitsu et al. (1996); Evans & Weber (1986); Heimgartner (1991); Rando (1975); Griesbeck et al. (2003); Zhang et al. (2004); Wang et al. (2010). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986). For standard bond-length data, see: Allen et al. (1987). For ring conformations, see: Cremer & Pople (1975). For related structures, see: Fun et al. (2011a,b,c,d). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

The title compound was the main product from the acid-catalyzed transformation of the photocycloadducts of isoquinoline-1,3,4-trione and 4-isobutyl-5-methoxy-2-methyloxazole. The compound was purified by flash column chromatography with ethyl acetate/petroleum ether (1:5) as eluents. X-ray quality crystals of the title compound were obtained from slow evaporation of an acetone and petroleum ether solution (1:8) of the title compound, m.p. 425-427 K.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound showing 50% probability displacement ellipsoids for non-H atoms. Intramolecular hydrogen bond is shown as dashed line.
	Fig. 2. Part of the crystal structure of the title compound, viewed along the b axis. H atoms not involved in hydrogen bonds (dashed lines) have been omitted for clarity.

Methyl 2-acetamido-2-(4-hydroxy-2-methyl-1,3-dioxo- 1,2,3,4-tetrahydroisoquinolin-4-yl)-4-methylpentanoate top

Crystal data top

C₁₉H₂₄N₂O₆	F(000) = 800
M_r = 376.40	D_x = 1.366 Mg m⁻³
Monoclinic, Cc	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: C -2yc	Cell parameters from 9888 reflections
a = 17.8256 (15) Å	θ = 5.1–64.2°
b = 8.7584 (6) Å	µ = 0.85 mm⁻¹
c = 11.9182 (8) Å	T = 100 K
β = 100.404 (5)°	Needle, colourless
V = 1830.1 (2) Å³	0.50 × 0.15 × 0.15 mm
Z = 4

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	2713 independent reflections
Radiation source: fine-focus sealed tube	2673 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
ϕ and ω scans	θ_max = 64.7°, θ_min = 5.1°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −20→20
T_min = 0.678, T_max = 0.883	k = −9→10
18268 measured reflections	l = −12→13

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.024	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.059	w = 1/[σ²(F_o²) + (0.0319P)² + 0.7184P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
2713 reflections	Δρ_max = 0.11 e Å⁻³
257 parameters	Δρ_min = −0.14 e Å⁻³
2 restraints	Absolute structure: Flack (1983), 1204 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.05 (13)

Crystal data top

C₁₉H₂₄N₂O₆	V = 1830.1 (2) Å³
M_r = 376.40	Z = 4
Monoclinic, Cc	Cu Kα radiation
a = 17.8256 (15) Å	µ = 0.85 mm⁻¹
b = 8.7584 (6) Å	T = 100 K
c = 11.9182 (8) Å	0.50 × 0.15 × 0.15 mm
β = 100.404 (5)°

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	2713 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	2673 reflections with I > 2σ(I)
T_min = 0.678, T_max = 0.883	R_int = 0.033
18268 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.024	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.059	Δρ_max = 0.11 e Å⁻³
S = 1.05	Δρ_min = −0.14 e Å⁻³
2713 reflections	Absolute structure: Flack (1983), 1204 Friedel pairs
257 parameters	Absolute structure parameter: 0.05 (13)
2 restraints

Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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
O1	0.81985 (6)	0.74615 (13)	1.04040 (10)	0.0229 (3)
O2	1.05834 (6)	0.65801 (14)	0.97375 (10)	0.0302 (3)
O3	0.76692 (6)	0.48621 (12)	0.94001 (10)	0.0204 (2)
O4	0.91523 (6)	0.77211 (12)	0.76247 (9)	0.0193 (2)
O5	0.89019 (6)	0.56633 (12)	0.65074 (9)	0.0204 (2)
O6	0.64674 (6)	0.52211 (12)	0.77471 (10)	0.0223 (3)
N1	0.93918 (7)	0.70763 (15)	1.00450 (11)	0.0206 (3)
N2	0.75643 (7)	0.51865 (14)	0.70247 (12)	0.0171 (3)
C1	0.86194 (9)	0.67556 (17)	0.99008 (14)	0.0188 (3)
C2	0.99257 (9)	0.61559 (19)	0.96548 (14)	0.0222 (4)
C3	0.96586 (9)	0.46387 (18)	0.91865 (14)	0.0200 (3)
C4	1.02036 (9)	0.3555 (2)	0.90385 (14)	0.0253 (4)
H4A	1.0719	0.3803	0.9194	0.030*
C5	0.99735 (10)	0.2104 (2)	0.86574 (15)	0.0285 (4)
H5A	1.0334	0.1376	0.8550	0.034*
C6	0.92023 (10)	0.17437 (19)	0.84364 (15)	0.0259 (4)
H6A	0.9049	0.0765	0.8192	0.031*
C7	0.86576 (9)	0.28210 (18)	0.85750 (14)	0.0217 (3)
H7A	0.8143	0.2565	0.8424	0.026*
C8	0.88811 (8)	0.42821 (18)	0.89389 (13)	0.0181 (3)
C9	0.82982 (8)	0.55120 (17)	0.90207 (14)	0.0174 (3)
C10	0.80278 (8)	0.62935 (17)	0.77805 (14)	0.0167 (3)
C11	0.76008 (9)	0.78137 (17)	0.78789 (13)	0.0180 (3)
H11A	0.7260	0.7664	0.8419	0.022*
H11B	0.7974	0.8574	0.8201	0.022*
C12	0.71318 (9)	0.84730 (17)	0.67768 (15)	0.0217 (3)
H12A	0.6734	0.7732	0.6477	0.026*
C13	0.75969 (10)	0.8792 (2)	0.58470 (15)	0.0285 (4)
H13A	0.7803	0.7852	0.5620	0.043*
H13B	0.8006	0.9479	0.6135	0.043*
H13C	0.7274	0.9246	0.5201	0.043*
C14	0.67409 (10)	0.9933 (2)	0.70714 (17)	0.0306 (4)
H14A	0.6414	1.0315	0.6401	0.046*
H14B	0.7120	1.0686	0.7352	0.046*
H14C	0.6443	0.9716	0.7647	0.046*
C15	0.87344 (8)	0.65099 (17)	0.72155 (14)	0.0165 (3)
C16	0.98383 (9)	0.79217 (19)	0.71419 (15)	0.0230 (4)
H16A	1.0110	0.8807	0.7472	0.035*
H16B	0.9701	0.8053	0.6331	0.035*
H16C	1.0158	0.7037	0.7304	0.035*
C17	0.68252 (8)	0.48575 (17)	0.69911 (14)	0.0179 (3)
C18	0.64504 (9)	0.40140 (19)	0.59393 (15)	0.0248 (4)
H18A	0.6056	0.3365	0.6124	0.037*
H18B	0.6824	0.3404	0.5657	0.037*
H18C	0.6232	0.4734	0.5365	0.037*
C19	0.96743 (10)	0.84909 (19)	1.06333 (17)	0.0300 (4)
H19A	0.9273	0.8958	1.0952	0.045*
H19B	0.9839	0.9179	1.0100	0.045*
H19C	1.0096	0.8261	1.1233	0.045*
H1N2	0.7798 (11)	0.479 (2)	0.6459 (18)	0.025 (5)*
H1O3	0.7237 (13)	0.510 (2)	0.8986 (18)	0.037 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0255 (6)	0.0248 (6)	0.0184 (7)	0.0040 (4)	0.0040 (5)	−0.0020 (5)
O2	0.0178 (6)	0.0408 (7)	0.0299 (8)	−0.0067 (5)	−0.0013 (5)	0.0021 (6)
O3	0.0173 (5)	0.0267 (6)	0.0173 (7)	−0.0020 (4)	0.0036 (5)	0.0027 (5)
O4	0.0171 (5)	0.0208 (5)	0.0201 (7)	−0.0039 (4)	0.0033 (4)	−0.0013 (5)
O5	0.0191 (5)	0.0237 (5)	0.0188 (7)	−0.0013 (4)	0.0046 (4)	−0.0021 (5)
O6	0.0177 (5)	0.0279 (6)	0.0215 (7)	−0.0011 (4)	0.0045 (5)	−0.0014 (5)
N1	0.0220 (7)	0.0223 (7)	0.0162 (8)	−0.0040 (5)	−0.0003 (5)	0.0005 (6)
N2	0.0163 (7)	0.0188 (7)	0.0161 (8)	−0.0006 (5)	0.0026 (6)	−0.0022 (5)
C1	0.0221 (8)	0.0190 (7)	0.0143 (9)	0.0005 (6)	0.0004 (6)	0.0044 (6)
C2	0.0195 (8)	0.0310 (9)	0.0143 (9)	−0.0008 (6)	−0.0019 (6)	0.0057 (7)
C3	0.0206 (8)	0.0281 (8)	0.0112 (9)	0.0010 (6)	0.0024 (6)	0.0038 (7)
C4	0.0210 (8)	0.0383 (10)	0.0163 (10)	0.0049 (7)	0.0027 (7)	0.0045 (7)
C5	0.0322 (10)	0.0339 (10)	0.0193 (11)	0.0139 (7)	0.0042 (7)	0.0002 (7)
C6	0.0352 (10)	0.0242 (9)	0.0168 (10)	0.0055 (7)	0.0009 (7)	0.0007 (7)
C7	0.0248 (8)	0.0246 (8)	0.0151 (9)	0.0009 (7)	0.0021 (6)	−0.0002 (7)
C8	0.0210 (8)	0.0239 (8)	0.0095 (9)	0.0021 (6)	0.0030 (6)	0.0028 (6)
C9	0.0167 (7)	0.0204 (8)	0.0149 (9)	−0.0010 (6)	0.0025 (6)	0.0017 (6)
C10	0.0161 (7)	0.0196 (7)	0.0130 (9)	−0.0030 (6)	−0.0007 (6)	−0.0009 (6)
C11	0.0159 (7)	0.0216 (8)	0.0163 (9)	0.0001 (6)	0.0025 (6)	0.0005 (6)
C12	0.0204 (7)	0.0219 (8)	0.0207 (10)	−0.0012 (6)	−0.0015 (6)	0.0013 (7)
C13	0.0318 (9)	0.0316 (9)	0.0212 (10)	0.0051 (7)	0.0022 (7)	0.0070 (8)
C14	0.0318 (9)	0.0302 (9)	0.0280 (12)	0.0085 (7)	0.0002 (8)	0.0036 (8)
C15	0.0156 (7)	0.0191 (8)	0.0134 (9)	−0.0003 (6)	−0.0010 (6)	0.0030 (6)
C16	0.0190 (8)	0.0264 (8)	0.0238 (10)	−0.0048 (6)	0.0043 (7)	0.0010 (7)
C17	0.0165 (7)	0.0178 (7)	0.0191 (10)	−0.0003 (6)	0.0018 (6)	0.0013 (6)
C18	0.0178 (8)	0.0319 (9)	0.0241 (10)	−0.0055 (7)	0.0024 (7)	−0.0034 (8)
C19	0.0364 (10)	0.0282 (9)	0.0235 (10)	−0.0103 (7)	0.0004 (8)	−0.0038 (8)

Geometric parameters (Å, º) top

O1—C1	1.211 (2)	C8—C9	1.512 (2)
O2—C2	1.217 (2)	C9—C10	1.621 (2)
O3—C9	1.4032 (19)	C10—C15	1.543 (2)
O3—H1O3	0.86 (2)	C10—C11	1.549 (2)
O4—C15	1.3368 (18)	C11—C12	1.537 (2)
O4—C16	1.4531 (18)	C11—H11A	0.9700
O5—C15	1.201 (2)	C11—H11B	0.9700
O6—C17	1.236 (2)	C12—C13	1.525 (3)
N1—C1	1.3851 (19)	C12—C14	1.527 (2)
N1—C2	1.390 (2)	C12—H12A	0.9800
N1—C19	1.467 (2)	C13—H13A	0.9600
N2—C17	1.3420 (19)	C13—H13B	0.9600
N2—C10	1.4715 (19)	C13—H13C	0.9600
N2—H1N2	0.92 (2)	C14—H14A	0.9600
C1—C9	1.548 (2)	C14—H14B	0.9600
C2—C3	1.486 (2)	C14—H14C	0.9600
C3—C4	1.392 (2)	C16—H16A	0.9600
C3—C8	1.399 (2)	C16—H16B	0.9600
C4—C5	1.386 (3)	C16—H16C	0.9600
C4—H4A	0.9300	C17—C18	1.504 (2)
C5—C6	1.389 (3)	C18—H18A	0.9600
C5—H5A	0.9300	C18—H18B	0.9600
C6—C7	1.385 (2)	C18—H18C	0.9600
C6—H6A	0.9300	C19—H19A	0.9600
C7—C8	1.386 (2)	C19—H19B	0.9600
C7—H7A	0.9300	C19—H19C	0.9600

C9—O3—H1O3	113.6 (14)	C10—C11—H11A	108.0
C15—O4—C16	113.89 (13)	C12—C11—H11B	108.0
C1—N1—C2	124.49 (13)	C10—C11—H11B	108.0
C1—N1—C19	118.57 (13)	H11A—C11—H11B	107.2
C2—N1—C19	116.93 (13)	C13—C12—C14	110.13 (14)
C17—N2—C10	126.82 (13)	C13—C12—C11	114.00 (13)
C17—N2—H1N2	117.8 (12)	C14—C12—C11	108.57 (14)
C10—N2—H1N2	114.8 (12)	C13—C12—H12A	108.0
O1—C1—N1	121.72 (14)	C14—C12—H12A	108.0
O1—C1—C9	120.54 (14)	C11—C12—H12A	108.0
N1—C1—C9	117.67 (13)	C12—C13—H13A	109.5
O2—C2—N1	120.25 (15)	C12—C13—H13B	109.5
O2—C2—C3	122.84 (15)	H13A—C13—H13B	109.5
N1—C2—C3	116.87 (13)	C12—C13—H13C	109.5
C4—C3—C8	120.56 (15)	H13A—C13—H13C	109.5
C4—C3—C2	118.28 (14)	H13B—C13—H13C	109.5
C8—C3—C2	121.12 (14)	C12—C14—H14A	109.5
C5—C4—C3	119.65 (16)	C12—C14—H14B	109.5
C5—C4—H4A	120.2	H14A—C14—H14B	109.5
C3—C4—H4A	120.2	C12—C14—H14C	109.5
C4—C5—C6	119.64 (16)	H14A—C14—H14C	109.5
C4—C5—H5A	120.2	H14B—C14—H14C	109.5
C6—C5—H5A	120.2	O5—C15—O4	123.60 (14)
C7—C6—C5	120.92 (16)	O5—C15—C10	123.84 (13)
C7—C6—H6A	119.5	O4—C15—C10	112.54 (13)
C5—C6—H6A	119.5	O4—C16—H16A	109.5
C6—C7—C8	119.87 (15)	O4—C16—H16B	109.5
C6—C7—H7A	120.1	H16A—C16—H16B	109.5
C8—C7—H7A	120.1	O4—C16—H16C	109.5
C7—C8—C3	119.33 (14)	H16A—C16—H16C	109.5
C7—C8—C9	121.04 (13)	H16B—C16—H16C	109.5
C3—C8—C9	119.57 (14)	O6—C17—N2	123.78 (14)
O3—C9—C8	109.28 (12)	O6—C17—C18	121.61 (13)
O3—C9—C1	106.64 (13)	N2—C17—C18	114.60 (14)
C8—C9—C1	111.74 (12)	C17—C18—H18A	109.5
O3—C9—C10	109.99 (12)	C17—C18—H18B	109.5
C8—C9—C10	109.67 (13)	H18A—C18—H18B	109.5
C1—C9—C10	109.47 (12)	C17—C18—H18C	109.5
N2—C10—C15	103.07 (12)	H18A—C18—H18C	109.5
N2—C10—C11	112.55 (12)	H18B—C18—H18C	109.5
C15—C10—C11	112.23 (12)	N1—C19—H19A	109.5
N2—C10—C9	108.76 (12)	N1—C19—H19B	109.5
C15—C10—C9	108.54 (11)	H19A—C19—H19B	109.5
C11—C10—C9	111.30 (13)	N1—C19—H19C	109.5
C12—C11—C10	117.22 (13)	H19A—C19—H19C	109.5
C12—C11—H11A	108.0	H19B—C19—H19C	109.5

C2—N1—C1—O1	168.38 (15)	O1—C1—C9—C8	−151.28 (14)
C19—N1—C1—O1	−12.6 (2)	N1—C1—C9—C8	31.84 (19)
C2—N1—C1—C9	−14.8 (2)	O1—C1—C9—C10	87.02 (17)
C19—N1—C1—C9	164.27 (14)	N1—C1—C9—C10	−89.86 (15)
C1—N1—C2—O2	174.17 (15)	C17—N2—C10—C15	−164.63 (14)
C19—N1—C2—O2	−4.9 (2)	C17—N2—C10—C11	−43.5 (2)
C1—N1—C2—C3	−8.2 (2)	C17—N2—C10—C9	80.31 (18)
C19—N1—C2—C3	172.78 (14)	O3—C9—C10—N2	−49.92 (16)
O2—C2—C3—C4	12.4 (2)	C8—C9—C10—N2	70.29 (15)
N1—C2—C3—C4	−165.20 (15)	C1—C9—C10—N2	−166.77 (12)
O2—C2—C3—C8	−169.92 (15)	O3—C9—C10—C15	−161.37 (12)
N1—C2—C3—C8	12.5 (2)	C8—C9—C10—C15	−41.16 (16)
C8—C3—C4—C5	−0.9 (2)	C1—C9—C10—C15	81.77 (14)
C2—C3—C4—C5	176.79 (16)	O3—C9—C10—C11	74.64 (15)
C3—C4—C5—C6	−0.5 (3)	C8—C9—C10—C11	−165.15 (12)
C4—C5—C6—C7	1.0 (3)	C1—C9—C10—C11	−42.22 (16)
C5—C6—C7—C8	0.0 (3)	N2—C10—C11—C12	−42.05 (18)
C6—C7—C8—C3	−1.4 (2)	C15—C10—C11—C12	73.68 (17)
C6—C7—C8—C9	175.79 (15)	C9—C10—C11—C12	−164.44 (12)
C4—C3—C8—C7	1.9 (2)	C10—C11—C12—C13	−58.65 (18)
C2—C3—C8—C7	−175.74 (15)	C10—C11—C12—C14	178.18 (13)
C4—C3—C8—C9	−175.38 (15)	C16—O4—C15—O5	−0.5 (2)
C2—C3—C8—C9	7.0 (2)	C16—O4—C15—C10	177.71 (12)
C7—C8—C9—O3	37.1 (2)	N2—C10—C15—O5	−15.55 (19)
C3—C8—C9—O3	−145.72 (14)	C11—C10—C15—O5	−136.90 (15)
C7—C8—C9—C1	154.86 (15)	C9—C10—C15—O5	99.66 (17)
C3—C8—C9—C1	−27.9 (2)	N2—C10—C15—O4	166.23 (12)
C7—C8—C9—C10	−83.55 (17)	C11—C10—C15—O4	44.89 (17)
C3—C8—C9—C10	93.64 (17)	C9—C10—C15—O4	−78.55 (14)
O1—C1—C9—O3	−31.9 (2)	C10—N2—C17—O6	−15.0 (2)
N1—C1—C9—O3	151.20 (13)	C10—N2—C17—C18	164.21 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H1N2···O1ⁱ	0.92 (2)	2.511 (19)	3.3431 (17)	150.3 (15)
N2—H1N2···O3ⁱ	0.92 (2)	2.44 (2)	3.1675 (18)	135.6 (16)
O3—H1O3···O6	0.86 (2)	1.83 (2)	2.6543 (16)	160 (2)
C5—H5A···O6ⁱⁱ	0.93	2.59	3.469 (2)	157

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

Experimental details

Crystal data
Chemical formula	C₁₉H₂₄N₂O₆
M_r	376.40
Crystal system, space group	Monoclinic, Cc
Temperature (K)	100
a, b, c (Å)	17.8256 (15), 8.7584 (6), 11.9182 (8)
β (°)	100.404 (5)
V (Å³)	1830.1 (2)
Z	4
Radiation type	Cu Kα
µ (mm⁻¹)	0.85
Crystal size (mm)	0.50 × 0.15 × 0.15

Data collection
Diffractometer	Bruker APEX DUO CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.678, 0.883
No. of measured, independent and observed [I > 2σ(I)] reflections	18268, 2713, 2673
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.586

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.024, 0.059, 1.05
No. of reflections	2713
No. of parameters	257
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.11, −0.14
Absolute structure	Flack (1983), 1204 Friedel pairs
Absolute structure parameter	0.05 (13)

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H1N2···O1ⁱ	0.92 (2)	2.511 (19)	3.3431 (17)	150.3 (15)
N2—H1N2···O3ⁱ	0.92 (2)	2.44 (2)	3.1675 (18)	135.6 (16)
O3—H1O3···O6	0.86 (2)	1.83 (2)	2.6543 (16)	160 (2)
C5—H5A···O6ⁱⁱ	0.93	2.59	3.469 (2)	157

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

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

§Thomson Reuters ResearcherID: A-5525-2009.

Acknowledgements

HKF and CKQ thank Universiti Sains Malaysia for the Research University Grant (No. 1001/PFIZIK/811160). Financial support from the Ministry of Science and Technology of China of the Austria–China Cooperation project (2007DFA41590) is also acknowledged.

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