Dimethyl 2-methyl-1,2-dihydro­quinoline-2,4-dicarboxyl­ate

Gültekin, Z.; Frey, W.; Tercan, B.; Hökelek, T.

doi:10.1107/S1600536811005605

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 3| March 2011| Pages o672-o673

doi:10.1107/S1600536811005605

Open

access

Dimethyl 2-methyl-1,2-dihydroquinoline-2,4-dicarboxylate

Zeynep Gültekin,^a Wolfgang Frey,^b Barış Tercan ^c and Tuncer Hökelek ^d ^*

^aDepartment of Chemistry, Çankırı Karatekin University, TR-18100 Çankırı, Turkey, ^bUniversitat Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, ^cDepartment of Physics, Karabük University, 78050 Karabük, Turkey, and ^dDepartment of Physics, Hacettepe University, 06800 Beytepe, Ankara, Turkey
^*Correspondence e-mail: merzifon@hacettepe.edu.tr

(Received 13 January 2011; accepted 15 February 2011; online 19 February 2011)

In the crystal of the title compound, C₁₄H₁₅NO₄, pairs of intermolecular N—H⋯O hydrogen bonds link the molecules into centrosymmetric R₂²(10) dimers. These dimers are further connected via intermolecular C—H⋯O hydrogen bonds, forming a three-dimensional network. The heterocyclic ring adopts a twisted conformation.

Related literature

For the preparation of 1,2-dihydroquinoline, see: Edwards et al. (1998 ); Yan et al. (2004 ); Petasis & Butkevich (2009 ); Johnson et al. (1989 ); Gültekin et al. (2010 ); Waldmann et al. (2008 ). For the biological activity of dihydroquinolines, see: Elmore et al. (2001 ); Dillard et al. (1973 ); Muren & Weissman (1971 ). For the preparation of quinolines, see: Dauphinee & Forrest (1978 ); Yan et al. (2004); Tom & Ruel (2001 ); Tokuyama et al. (2001 ); Sarma & Prajapati (2008 ); Martinez et al. (2008 ); Huang et al. (2009 ); Katritzky et al. (1996 ). For the biological activity of quinolines, see: Hamann et al. (1998 ); He et al. (2003 ); LaMontagne et al. (1989 ). For hydorgen-bond motifs, see: Bernstein et al. (1995 ). For ring puckering parameters, see: Cremer & Pople (1975 ). For the melting point, see: Rueping & Gültekin (2009 ).

Experimental

Crystal data

C₁₄H₁₅NO₄
M_r = 261.27
Monoclinic, P 2₁ /n
a = 7.9917 (12) Å
b = 8.8886 (11) Å
c = 18.9855 (18) Å
β = 99.194 (9)°
V = 1331.3 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 294 K
0.6 × 0.6 × 0.5 mm

Data collection

Nicolet P3 diffractometer
4144 measured reflections
3890 independent reflections
3097 reflections with I > 2σ(I)
R_int = 0.053
3 standard reflections every 50 reflections intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.052
wR(F²) = 0.159
S = 1.05
3890 reflections
180 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 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⋯O1ⁱ	0.91 (2)	2.22 (2)	3.1241 (18)	174 (2)
C12—H12A⋯O3ⁱⁱ	0.96	2.57	3.377 (3)	142
C12—H12C⋯O3ⁱⁱⁱ	0.96	2.49	3.336 (2)	148
Symmetry codes: (i) -x, -y+1, -z+2; (ii) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (iii) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: XSCANS (Siemens, 1996 ); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811005605/bv2176sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811005605/bv2176Isup2.hkl

checkCIF report

Comment top

Dihydroquinolines have been widely studied and found to be an important structural unit in synthetic organic and medicinal chemistry (Elmore et al., 2001; Dillard et al., 1973; Muren & Weissman, 1971). Many dihydroquinoline derivatives have been reported in the literature (Edwards et al., 1998; Yan et al., 2004; Petasis & Butkevich, 2009; Gültekin et al., 2010) and some of them have biological effects. For example, 2,2,4-substituted 1,2-dihydroquinolines have been shown to possess antibacterial activities (Johnson et al., 1989). They are also important intermediates for the preparation of quinolines (Dauphinee & Forrest, 1978; Yan et al., 2004; Tom & Ruel, 2001; Tokuyama et al., 2001) and 1,2,3,4-tetrahydroquinolines (Katritzky et al., 1996). Many synthetic methods have been developed for the preparation of quinolines (Sarma & Prajapati, 2008; Martinez et al., 2008; Huang et al., 2009; Waldmann et al., 2008) and many quinolines display biological effects (Hamann et al., 1998; He et al., 2003; LaMontagne et al., 1989; Muren & Weissman, 1971).

In the title compound, (I), (Fig. 1), the ring A (C1-C4/C9/N1) is not planar with the puckering parameters (Cremer & Pople, 1975) Q_T = 0.364 (2) Å, ϕ = -143.4 (3)° and θ = 113.9 (2)°.

In the crystal structure, intermolecular N-H···O hydrogen bonds (Table 1) link the molecules into centrosymmetric R₂²(10) dimers (Bernstein et al., 1995). These dimers are further connected via intermolecular C-H···O hydrogen bonds (Table 1) to form a three-dimensional network (Fig. 2).

Related literature top

For the preparation of 1,2-dihydroquinoline, see: Edwards et al. (1998); Yan et al. (2004); Petasis & Butkevich (2009); Johnson et al. (1989); Gültekin et al. (2010); Waldmann et al. (2008). For the biological activity of dihydroquinolines, see: Elmore et al. (2001); Dillard et al. (1973); Muren & Weissman (1971). For the preparation of quinolines, see: Dauphinee & Forrest (1978); Yan et al. (2004); Tom & Ruel (2001); Tokuyama et al. (2001); Sarma & Prajapati (2008); Martinez et al. (2008); Huang et al. (2009); Katritzky et al. (1996). For the biological activity of quinolines, see: Hamann et al. (1998); He et al. (2003); LaMontagne et al. (1989). For hydorgen-bond motifs, see: Bernstein et al. (1995). For ring puckering parameters, see: Cremer & Pople (1975). For the melting point [OK?], see: Rueping & Gültekin (2009).

Experimental top

The title compound was synthesized by the literature method (Waldmann et al., 2008). Aniline (100 mg, 1 eq) was dissolved in chloroform (1.5 ml) in a screw-capped test tube and Bi(OTf)₃ (5 mol%, 0.05 eq) was added to the mixture. The mixture was stirred at room temperature for 4h until the starting material was completely consumed as monitored by TLC. The resultant residue was directly purified by flash chromatography on silica (EtOAc:Cylohexane 2:98) gave in 63% yield as a yellow solid. Recrystallized over pentane and ethyl acetate (70:30) gave yellow crystalline solid R_f 0.53 (2:1 Cyclohexane/EtOAc) mp 346 K (Rueping & Gültekin, 2009).

Computing details top

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS (Siemens, 1996); data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A partial packing diagram viewed down the b-axis. Hydrogen bonds are shown as dashed lines.

Dimethyl 2-methyl-1,2-dihydroquinoline-2,4-dicarboxylate top

Crystal data top

C₁₄H₁₅NO₄	F(000) = 552
M_r = 261.27	D_x = 1.304 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 49 reflections
a = 7.9917 (12) Å	θ = 17–18°
b = 8.8886 (11) Å	µ = 0.10 mm⁻¹
c = 18.9855 (18) Å	T = 294 K
β = 99.194 (9)°	Block, colourless
V = 1331.3 (3) Å³	0.6 × 0.6 × 0.5 mm
Z = 4

Data collection top

Nicolet P3 diffractometer	R_int = 0.053
Radiation source: fine-focus sealed tube	θ_max = 30.0°, θ_min = 2.2°
Graphite monochromator	h = 0→11
Wyckoff–Scan scans	k = 0→12
4144 measured reflections	l = −26→26
3890 independent reflections	3 standard reflections every 50 reflections
3097 reflections with I > 2σ(I)	intensity decay: 1%

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)] = 0.052	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.159	w = 1/[σ²(F_o²) + (0.0757P)² + 0.2951P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
3890 reflections	Δρ_max = 0.24 e Å⁻³
180 parameters	Δρ_min = −0.18 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.076 (5)

Crystal data top

C₁₄H₁₅NO₄	V = 1331.3 (3) Å³
M_r = 261.27	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 7.9917 (12) Å	µ = 0.10 mm⁻¹
b = 8.8886 (11) Å	T = 294 K
c = 18.9855 (18) Å	0.6 × 0.6 × 0.5 mm
β = 99.194 (9)°

Data collection top

Nicolet P3 diffractometer	R_int = 0.053
4144 measured reflections	3 standard reflections every 50 reflections
3890 independent reflections	intensity decay: 1%
3097 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.052	0 restraints
wR(F²) = 0.159	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.24 e Å⁻³
3890 reflections	Δρ_min = −0.18 e Å⁻³
180 parameters

Special details top

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	0.16885 (15)	0.61815 (14)	0.96958 (6)	0.0632 (3)
O2	0.15641 (17)	0.84306 (14)	0.91740 (6)	0.0671 (4)
O3	−0.04420 (19)	0.60887 (14)	0.63398 (6)	0.0688 (4)
O4	0.00900 (15)	0.83447 (13)	0.68455 (5)	0.0538 (3)
N1	−0.12790 (17)	0.52602 (16)	0.88407 (7)	0.0527 (3)
H1	−0.137 (3)	0.491 (3)	0.9282 (12)	0.080 (6)*
C1	−0.08128 (18)	0.68333 (17)	0.88397 (7)	0.0447 (3)
C2	−0.07661 (18)	0.73116 (16)	0.80816 (7)	0.0441 (3)
H2	−0.1036	0.8299	0.7946	0.053*
C3	−0.03445 (17)	0.63452 (15)	0.76014 (7)	0.0411 (3)
C4	−0.00240 (17)	0.47523 (15)	0.77879 (7)	0.0439 (3)
C5	0.0730 (2)	0.37209 (18)	0.73815 (9)	0.0551 (4)
H5	0.1104	0.4042	0.6967	0.066*
C6	0.0929 (2)	0.22295 (19)	0.75842 (11)	0.0675 (5)
H6	0.1440	0.1557	0.7309	0.081*
C7	0.0370 (3)	0.17430 (19)	0.81939 (12)	0.0723 (5)
H7	0.0479	0.0734	0.8323	0.087*
C8	−0.0351 (2)	0.27357 (19)	0.86154 (10)	0.0630 (4)
H8	−0.0718	0.2393	0.9028	0.076*
C9	−0.05340 (17)	0.42528 (16)	0.84272 (8)	0.0468 (3)
C10	−0.2084 (2)	0.7764 (2)	0.91791 (10)	0.0689 (5)
H10A	−0.2112	0.7408	0.9654	0.103*
H10B	−0.3191	0.7667	0.8899	0.103*
H10C	−0.1749	0.8802	0.9197	0.103*
C11	0.09548 (18)	0.70811 (16)	0.92869 (6)	0.0432 (3)
C12	0.3182 (3)	0.8827 (3)	0.95860 (10)	0.0782 (6)
H12A	0.3519	0.9801	0.9441	0.117*
H12B	0.4015	0.8094	0.9507	0.117*
H12C	0.3087	0.8848	1.0084	0.117*
C13	−0.02495 (18)	0.68793 (17)	0.68624 (7)	0.0455 (3)
C14	0.0372 (3)	0.8942 (2)	0.61686 (9)	0.0639 (4)
H14A	0.0545	1.0009	0.6209	0.096*
H14B	−0.0598	0.8739	0.5813	0.096*
H14C	0.1355	0.8477	0.6032	0.096*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0643 (7)	0.0639 (7)	0.0556 (6)	−0.0034 (5)	−0.0082 (5)	0.0187 (5)
O2	0.0860 (9)	0.0569 (7)	0.0495 (6)	−0.0208 (6)	−0.0163 (6)	0.0115 (5)
O3	0.1070 (10)	0.0603 (7)	0.0347 (5)	0.0046 (7)	−0.0018 (6)	−0.0064 (5)
O4	0.0706 (7)	0.0516 (6)	0.0369 (5)	−0.0038 (5)	0.0014 (4)	0.0041 (4)
N1	0.0563 (7)	0.0561 (7)	0.0457 (6)	−0.0088 (6)	0.0077 (5)	0.0054 (5)
C1	0.0484 (7)	0.0491 (7)	0.0360 (6)	0.0029 (6)	0.0048 (5)	0.0012 (5)
C2	0.0518 (7)	0.0421 (6)	0.0356 (6)	0.0049 (5)	−0.0014 (5)	0.0021 (5)
C3	0.0438 (6)	0.0423 (6)	0.0340 (5)	0.0002 (5)	−0.0033 (5)	0.0004 (5)
C4	0.0449 (6)	0.0411 (6)	0.0415 (6)	−0.0011 (5)	−0.0056 (5)	−0.0011 (5)
C5	0.0600 (9)	0.0502 (8)	0.0507 (8)	0.0060 (7)	−0.0046 (6)	−0.0072 (6)
C6	0.0735 (11)	0.0476 (8)	0.0732 (11)	0.0094 (8)	−0.0133 (9)	−0.0119 (8)
C7	0.0816 (12)	0.0385 (8)	0.0861 (13)	−0.0058 (8)	−0.0198 (10)	0.0041 (8)
C8	0.0688 (10)	0.0475 (8)	0.0666 (10)	−0.0150 (7)	−0.0081 (8)	0.0117 (7)
C9	0.0450 (7)	0.0444 (7)	0.0470 (7)	−0.0092 (5)	−0.0054 (5)	0.0037 (5)
C10	0.0674 (10)	0.0854 (13)	0.0559 (9)	0.0197 (9)	0.0157 (8)	−0.0024 (9)
C11	0.0522 (7)	0.0478 (7)	0.0296 (5)	−0.0014 (5)	0.0063 (5)	0.0015 (5)
C12	0.0917 (13)	0.0891 (14)	0.0472 (9)	−0.0413 (12)	−0.0086 (8)	0.0045 (9)
C13	0.0498 (7)	0.0487 (7)	0.0343 (6)	0.0046 (6)	−0.0042 (5)	−0.0008 (5)
C14	0.0774 (11)	0.0698 (11)	0.0430 (8)	−0.0016 (8)	0.0053 (7)	0.0141 (7)

Geometric parameters (Å, º) top

O1—C11	1.2001 (17)	C5—C6	1.382 (2)
O2—C11	1.3249 (18)	C5—H5	0.9300
O2—C12	1.443 (2)	C6—C7	1.376 (3)
O3—C13	1.2055 (17)	C6—H6	0.9300
O4—C13	1.3319 (19)	C7—C8	1.377 (3)
O4—C14	1.4410 (18)	C7—H7	0.9300
N1—C1	1.447 (2)	C8—C9	1.397 (2)
N1—C9	1.386 (2)	C8—H8	0.9300
N1—H1	0.91 (2)	C10—H10A	0.9600
C1—C2	1.5070 (18)	C10—H10B	0.9600
C1—C10	1.530 (2)	C10—H10C	0.9600
C1—C11	1.5432 (19)	C12—H12A	0.9600
C2—C3	1.3344 (19)	C12—H12B	0.9600
C2—H2	0.9300	C12—H12C	0.9600
C3—C4	1.4720 (19)	C14—H14A	0.9600
C3—C13	1.4944 (18)	C14—H14B	0.9600
C4—C5	1.395 (2)	C14—H14C	0.9600
C4—C9	1.412 (2)

C11—O2—C12	116.97 (13)	C7—C8—H8	119.8
C13—O4—C14	116.33 (13)	C9—C8—H8	119.8
C1—N1—H1	112.9 (15)	N1—C9—C4	119.52 (13)
C9—N1—C1	119.30 (12)	N1—C9—C8	121.05 (15)
C9—N1—H1	114.2 (14)	C8—C9—C4	119.37 (15)
N1—C1—C2	108.63 (12)	C1—C10—H10A	109.5
N1—C1—C10	109.48 (14)	C1—C10—H10B	109.5
N1—C1—C11	110.51 (12)	C1—C10—H10C	109.5
C2—C1—C10	111.66 (13)	H10A—C10—H10B	109.5
C2—C1—C11	108.97 (11)	H10A—C10—H10C	109.5
C10—C1—C11	107.59 (13)	H10B—C10—H10C	109.5
C1—C2—H2	119.4	O1—C11—O2	123.62 (14)
C3—C2—C1	121.23 (12)	O1—C11—C1	124.78 (13)
C3—C2—H2	119.4	O2—C11—C1	111.59 (12)
C2—C3—C4	120.53 (12)	O2—C12—H12A	109.5
C2—C3—C13	119.55 (12)	O2—C12—H12B	109.5
C4—C3—C13	119.90 (12)	O2—C12—H12C	109.5
C5—C4—C3	124.94 (13)	H12A—C12—H12B	109.5
C5—C4—C9	118.56 (14)	H12A—C12—H12C	109.5
C9—C4—C3	116.50 (13)	H12B—C12—H12C	109.5
C4—C5—H5	119.4	O3—C13—O4	123.36 (14)
C6—C5—C4	121.12 (17)	O3—C13—C3	124.65 (14)
C6—C5—H5	119.4	O4—C13—C3	111.99 (11)
C5—C6—H6	120.1	O4—C14—H14A	109.5
C7—C6—C5	119.82 (18)	O4—C14—H14B	109.5
C7—C6—H6	120.1	O4—C14—H14C	109.5
C6—C7—C8	120.64 (16)	H14A—C14—H14B	109.5
C6—C7—H7	119.7	H14A—C14—H14C	109.5
C8—C7—H7	119.7	H14B—C14—H14C	109.5
C7—C8—C9	120.43 (18)

C12—O2—C11—O1	−1.7 (2)	C2—C3—C4—C5	−167.06 (14)
C12—O2—C11—C1	177.32 (15)	C2—C3—C4—C9	13.20 (19)
C14—O4—C13—O3	−5.3 (2)	C13—C3—C4—C5	14.8 (2)
C14—O4—C13—C3	174.17 (13)	C13—C3—C4—C9	−164.94 (12)
C9—N1—C1—C2	44.10 (17)	C2—C3—C13—O3	−154.18 (16)
C9—N1—C1—C10	166.27 (14)	C2—C3—C13—O4	26.33 (18)
C9—N1—C1—C11	−75.40 (16)	C4—C3—C13—O3	24.0 (2)
C1—N1—C9—C4	−30.23 (19)	C4—C3—C13—O4	−155.51 (12)
C1—N1—C9—C8	152.77 (14)	C3—C4—C5—C6	−177.69 (14)
N1—C1—C2—C3	−31.14 (18)	C9—C4—C5—C6	2.0 (2)
C10—C1—C2—C3	−151.98 (15)	C3—C4—C9—N1	−0.52 (18)
C11—C1—C2—C3	89.32 (16)	C3—C4—C9—C8	176.53 (13)
N1—C1—C11—O1	−14.36 (19)	C5—C4—C9—N1	179.73 (13)
N1—C1—C11—O2	166.68 (12)	C5—C4—C9—C8	−3.2 (2)
C2—C1—C11—O1	−133.65 (15)	C4—C5—C6—C7	0.4 (3)
C2—C1—C11—O2	47.38 (16)	C5—C6—C7—C8	−1.6 (3)
C10—C1—C11—O1	105.13 (18)	C6—C7—C8—C9	0.4 (3)
C10—C1—C11—O2	−73.84 (16)	C7—C8—C9—N1	179.06 (15)
C1—C2—C3—C4	4.2 (2)	C7—C8—C9—C4	2.1 (2)
C1—C2—C3—C13	−177.68 (12)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.91 (2)	2.22 (2)	3.1241 (18)	174 (2)
C12—H12A···O3ⁱⁱ	0.96	2.57	3.377 (3)	142
C12—H12C···O3ⁱⁱⁱ	0.96	2.49	3.336 (2)	148

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

Experimental details

Crystal data
Chemical formula	C₁₄H₁₅NO₄
M_r	261.27
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	294
a, b, c (Å)	7.9917 (12), 8.8886 (11), 18.9855 (18)
β (°)	99.194 (9)
V (Å³)	1331.3 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.6 × 0.6 × 0.5

Data collection
Diffractometer	Nicolet P3 diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	4144, 3890, 3097
R_int	0.053
(sin θ/λ)_max (Å⁻¹)	0.703

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.159, 1.05
No. of reflections	3890
No. of parameters	180
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.18

Computer programs: XSCANS (Siemens, 1996), SHELXTL (Sheldrick, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.91 (2)	2.22 (2)	3.1241 (18)	174 (2)
C12—H12A···O3ⁱⁱ	0.96	2.57	3.377 (3)	142
C12—H12C···O3ⁱⁱⁱ	0.96	2.49	3.336 (2)	148

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

Acknowledgements

This research was carried out at RWTH Aachen University. The authors thank Professor Magnus Rueping of RWTH Aachen University, Germany, for helpful discussions.

References

Bernstein, J., Davies, R. E., Shimoni, L. & Chang, N. L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Dauphinee, G. A. & Forrest, T. P. (1978). Can. J. Chem. 56, 632–634. CrossRef CAS Web of Science Google Scholar
Dillard, R. D., Pavey, D. E. & Benslay, D. N. (1973). J. Med. Chem. 16, 251–253. CrossRef CAS PubMed Web of Science Google Scholar
Edwards, J. P., Ringgenberg, J. D. & Jones, T. K. (1998). Tetrahedron Lett. 39, 5139–5142. Web of Science CrossRef CAS Google Scholar
Elmore, S. W., Coghlan, M. J., Anderson, D. D., Pratt, J. K., Green, B. E., Wang, A. X., Stashko, M. A., Lin, C. W., Tyree, C. M., Miner, J. N., Jacobson, P. B., Wilcox, D. M. & Lane, B. C. (2001). J. Med. Chem. 44, 4481–4491. Web of Science CrossRef PubMed CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Gültekin, Z., Frey, W., Tercan, B. & Hökelek, T. (2010). Acta Cryst. E66, o2891–o2892. Web of Science CSD CrossRef IUCr Journals Google Scholar
Hamann, L. G., Higuchi, R. I., Zhi, L., Edwards, J. P., Wang, X. N., Marschke, K. B., Kong, J. W., Farmer, L. J. & Jones, T. K. (1998). J. Med. Chem. 41, 623–639. Web of Science CrossRef CAS PubMed Google Scholar
He, L., Chang, H. X., Chou, T. C., Savaraj, N. & Cheng, C. C. (2003). Eur. J. Med. Chem. 38, 101–107. Web of Science CrossRef PubMed CAS Google Scholar
Huang, H., Jiang, H., Chen, K. & Liu, H. (2009). J. Org. Chem. 74, 5476–5480. Web of Science CrossRef PubMed CAS Google Scholar
Johnson, J. V., Rauckman, B. S., Baccanari, D. P. & Roth, B. (1989). J. Med. Chem. 32, 1942–1949. CrossRef CAS PubMed Web of Science Google Scholar
Katritzky, A. R., Rachwal, S. & Rachwal, B. (1996). Tetrahedron. 52, 15031–15070. CrossRef CAS Web of Science Google Scholar
LaMontagne, M. P., Blumbergs, B. & Smith, D. C. (1989). J. Med. Chem. 32, 1728–1732. CrossRef CAS PubMed Web of Science Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CrossRef CAS IUCr Journals Google Scholar
Martinez, R., Ramon, D. J. & Yus, M. (2008). J. Org. Chem. 73, 9778–9780. Web of Science CrossRef PubMed CAS Google Scholar
Muren, J. F. & Weissman, A. (1971). J. Med. Chem. 14, 49–53. CAS PubMed Web of Science Google Scholar
Petasis, N. A. & Butkevich, A. N. (2009). J. Organomet. Chem. 694, 1747–1753. Web of Science CrossRef CAS PubMed Google Scholar
Rueping, M. & Gültekin, Z. (2009). Unpublished results. University of Aachen, Germany. Google Scholar
Sarma, R. & Prajapati, D. (2008). Synlett, pp. 3001–3005. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Siemens (1996). XSCANS. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar
Tokuyama, H., Sato, M., Ueda, T. & Fukuyama, T. (2001). Heterocycles, 54, 105–108. CAS Google Scholar
Tom, N. J. & Ruel, E. M. (2001). Synthesis, pp. 1351–1355. CrossRef Google Scholar
Waldmann, H., Karunakar, G. V. & Kumar, K. (2008). Org. Lett. 10, 2159–2162. Web of Science CrossRef PubMed CAS Google Scholar
Yan, M. C., Tu, Z. J., Lin, C. C., Ko, S. K., Hsu, J. M. & Yao, C. F. (2004). J. Org. Chem. 69, 1565–1570. Web of Science CSD CrossRef PubMed CAS Google Scholar