6-Amino-2-methyl-8-phenyl-1,2,3,4-tetra­hydro­iso­quinoline-5,7-dicarbo­nitrile

Wang, D.-C.; Song, H.; Yao, S.

doi:10.1107/S1600536813013342

organic compounds

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ISSN: 2056-9890

Volume 69| Part 6| June 2013| Page o929

doi:10.1107/S1600536813013342

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6-Amino-2-methyl-8-phenyl-1,2,3,4-tetrahydroisoquinoline-5,7-dicarbonitrile

Dao-Cai Wang,^a Hang Song ^a and Shun Yao ^a ^*

^aDepartment of Pharmaceutical and Biological Engineering, College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China
^*Correspondence e-mail: cusack@scu.edu.cn

(Received 19 April 2013; accepted 15 May 2013; online 22 May 2013)

In the title compound, C₁₈H₁₆N₄, the dihedral angle between the benzene and phenyl rings is 61.40 (4)°. In the crystal, molecules are linked by N—H⋯N(nitrile) hydrogen bonds, forming inversion dimers. The dimers are further linked by N—H⋯N(amine) hydrogen bonds, and both units are arranged almost perpendicular to each other [angle between dimer mean planes = 84.43 (12)°]. This arrangement is extended to form a ladder-like structure parallel to the c axis.

Related literature

For background to natural products containing an isoquinoline backbone, see: Marchand et al. (2006 ); Cho et al. (2007 ); Van Quaquebeke et al. (2007 ). For related structures, see: Rong et al. (2010 ); Balamurugan et al. (2011 ).

Experimental

Crystal data

C₁₈H₁₆N₄
M_r = 288.35
Monoclinic, P 2₁ /c
a = 17.5630 (5) Å
b = 6.25208 (19) Å
c = 13.7963 (4) Å
β = 93.209 (3)°
V = 1512.53 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 143 K
0.38 × 0.35 × 0.25 mm

Data collection

Agilent Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction, Yarnton, England.]$ ) T_min = 0.960, T_max = 1.000
6799 measured reflections
3089 independent reflections
2414 reflections with I > 2σ(I)
R_int = 0.034

Refinement

R[F² > 2σ(F²)] = 0.045
wR(F²) = 0.112
S = 1.05
3089 reflections
206 parameters
4 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4A⋯N2ⁱ	0.89 (1)	2.21 (1)	3.052 (2)	157 (2)
N4—H4B⋯N1ⁱⁱ	0.87 (1)	2.21 (1)	3.0261 (19)	155 (2)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction, Yarnton, England.]$ ); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009 ) and Mercury (Macrae et al., 2008 ); software used to prepare material for publication: OLEX2.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536813013342/bh2477sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813013342/bh2477Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813013342/bh2477Isup3.cml

checkCIF report

Comment top

Various natural products containing an isoquinoline backbone have received considerable attention over the past years, because of their different kinds of bioactivities (Marchand et al., 2006; Cho et al., 2007; Van Quaquebeke et al., 2007). The development of efficient synthetic methods for isoquinoline and related derivatives is continuously attracting the attention of many chemists (Rong et al., 2010; Balamurugan et al., 2011). As a part of our current studies on the development of new routes in organic synthesis and the screen of anticancer drugs, in this article, we report the crystal structure of the title compound (Fig. 1).

The dihedral angle between the benzene and the phenyl rings is 61.40 (4)°. In the crystal (Fig. 2), two kinds of hydrogen bonds are formed, i.e., N—H···N(nitrile group) and N—H···N(amine) hydrogen bonds, connecting molecules in different directions. The N—H···N(nitrile group) hydrogen bonds are involved in the formation of centrosymmetric dimers, and this basic unit is linked by N—H···N(amine) hydrogen bonds to four other symmetry-related units, which are parallel to each other. Non-parallel units are arranged almost perpendicular to each other [angle between unit mean planes: 84.43 (12)°] forming a ladder structure, that can extend into infinite sheets through the vertical direction of the step cross section. On the step cross section, the distance between the centers of two units is 6.252 (13) Å.

Related literature top

For background to natural products containing an isoquinoline backbone, see: Marchand et al. (2006); Cho et al. (2007); Van Quaquebeke et al. (2007). For related structures, see: Rong et al. (2010); Balamurugan et al. (2011).

Experimental top

Benzaldehyde (1 mmol) was added to a stirred solution of 1-methyl-4-piperidone (1 mmol) and tetrahydro pyrrole (1.2 mmol) in dichloromethane. The resulting mixture was refluxed for 4 h to obtain a α,β-unsaturated ketone as an intermediate. Subsequently, this α,β-unsaturated ketone (1 mmol) was reacted with malononitrile (2 mmol) under strong basic conditions (Rong et al., 2009), monitoring the reaction progress by TLC. After the completion of the reaction, the solvent was evaporated under reduce pressure and the crude product was purified by silica gel column chromatography. Crystals suitable for X-ray analysis were obtained by slow evaporation of a solution in methanol and dichloromethane (4:1).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 30% probability level.
	Fig. 2. The crystal packing of the title compound. H atoms not involved in hydrogen bonding are omitted for clarity.

6-Amino-2-methyl-8-phenyl-1,2,3,4-tetrahydroisoquinoline-5,7-dicarbonitrile top

Crystal data top

C₁₈H₁₆N₄	F(000) = 608
M_r = 288.35	D_x = 1.266 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.7107 Å
a = 17.5630 (5) Å	Cell parameters from 2345 reflections
b = 6.25208 (19) Å	θ = 3.0–29.0°
c = 13.7963 (4) Å	µ = 0.08 mm⁻¹
β = 93.209 (3)°	T = 143 K
V = 1512.53 (8) Å³	Block, colourless
Z = 4	0.38 × 0.35 × 0.25 mm

Data collection top

Agilent Xcalibur Eos diffractometer	3089 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2414 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.034
Detector resolution: 16.0874 pixels mm^-1	θ_max = 26.4°, θ_min = 3.0°
ω scans	h = −21→21
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −7→7
T_min = 0.960, T_max = 1.000	l = −16→17
6799 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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.112	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ²(F_o²) + (0.0403P)² + 0.3434P] where P = (F_o² + 2F_c²)/3
3089 reflections	(Δ/σ)_max < 0.001
206 parameters	Δρ_max = 0.19 e Å⁻³
4 restraints	Δρ_min = −0.22 e Å⁻³
0 constraints

Crystal data top

C₁₈H₁₆N₄	V = 1512.53 (8) Å³
M_r = 288.35	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 17.5630 (5) Å	µ = 0.08 mm⁻¹
b = 6.25208 (19) Å	T = 143 K
c = 13.7963 (4) Å	0.38 × 0.35 × 0.25 mm
β = 93.209 (3)°

Data collection top

Agilent Xcalibur Eos diffractometer	3089 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	2414 reflections with I > 2σ(I)
T_min = 0.960, T_max = 1.000	R_int = 0.034
6799 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	4 restraints
wR(F²) = 0.112	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.19 e Å⁻³
3089 reflections	Δρ_min = −0.22 e Å⁻³
206 parameters

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

	x	y	z	U_iso*/U_eq
N1	0.29081 (7)	−0.2394 (2)	0.20203 (9)	0.0244 (3)
N2	0.50947 (9)	0.2855 (3)	0.43619 (13)	0.0498 (5)
N3	0.14961 (8)	0.4536 (2)	0.57681 (10)	0.0308 (3)
N4	0.34160 (8)	0.4642 (2)	0.53715 (11)	0.0323 (4)
H4A	0.3908 (8)	0.501 (3)	0.5410 (12)	0.039*
H4B	0.3136 (9)	0.524 (3)	0.5798 (11)	0.039*
C1	0.36603 (8)	0.1934 (2)	0.41825 (11)	0.0234 (3)
C2	0.31623 (9)	0.3112 (2)	0.47415 (11)	0.0223 (3)
C3	0.23791 (8)	0.2589 (2)	0.46164 (10)	0.0201 (3)
C4	0.21118 (8)	0.0990 (2)	0.39679 (10)	0.0199 (3)
C5	0.26291 (8)	−0.0177 (2)	0.34345 (10)	0.0207 (3)
C6	0.34051 (8)	0.0294 (2)	0.35473 (10)	0.0221 (3)
C7	0.39820 (9)	−0.0919 (3)	0.29916 (12)	0.0288 (4)
H7A	0.4417	−0.1330	0.3440	0.035*
H7B	0.4179	0.0024	0.2486	0.035*
C8	0.36428 (9)	−0.2911 (3)	0.25165 (12)	0.0274 (4)
H8A	0.3994	−0.3483	0.2043	0.033*
H8B	0.3572	−0.4021	0.3015	0.033*
C9	0.23529 (9)	−0.1913 (2)	0.27405 (11)	0.0238 (4)
H9A	0.2251	−0.3227	0.3113	0.029*
H9B	0.1868	−0.1457	0.2403	0.029*
C10	0.12744 (8)	0.0567 (2)	0.38652 (10)	0.0205 (3)
C11	0.07739 (9)	0.2175 (3)	0.35361 (11)	0.0251 (4)
H11	0.0967	0.3541	0.3374	0.030*
C12	−0.00049 (9)	0.1790 (3)	0.34448 (11)	0.0300 (4)
H12	−0.0343	0.2889	0.3217	0.036*
C13	−0.02895 (9)	−0.0187 (3)	0.36837 (11)	0.0306 (4)
H13	−0.0823	−0.0446	0.3623	0.037*
C14	0.02015 (9)	−0.1791 (3)	0.40108 (11)	0.0292 (4)
H14	0.0005	−0.3152	0.4174	0.035*
C15	0.09809 (9)	−0.1418 (2)	0.41021 (11)	0.0243 (4)
H15	0.1316	−0.2526	0.4328	0.029*
C16	0.44596 (9)	0.2426 (3)	0.42808 (12)	0.0311 (4)
C17	0.18663 (8)	0.3655 (2)	0.52358 (11)	0.0221 (3)
C18	0.26348 (10)	−0.4182 (3)	0.14143 (12)	0.0344 (4)
H18A	0.2595	−0.5464	0.1817	0.052*
H18B	0.2993	−0.4447	0.0909	0.052*
H18C	0.2132	−0.3833	0.1111	0.052*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0234 (7)	0.0257 (7)	0.0243 (7)	−0.0017 (6)	0.0042 (5)	−0.0057 (5)
N2	0.0229 (8)	0.0629 (11)	0.0644 (11)	−0.0121 (8)	0.0114 (7)	−0.0318 (9)
N3	0.0234 (7)	0.0328 (8)	0.0363 (8)	−0.0017 (6)	0.0042 (6)	−0.0068 (6)
N4	0.0208 (7)	0.0385 (8)	0.0383 (8)	−0.0093 (7)	0.0084 (6)	−0.0166 (7)
C1	0.0173 (8)	0.0276 (8)	0.0255 (8)	−0.0043 (6)	0.0033 (6)	−0.0005 (7)
C2	0.0215 (8)	0.0235 (8)	0.0222 (8)	−0.0039 (6)	0.0021 (6)	0.0006 (6)
C3	0.0191 (8)	0.0206 (8)	0.0207 (7)	−0.0003 (6)	0.0029 (6)	0.0023 (6)
C4	0.0185 (7)	0.0207 (8)	0.0204 (7)	−0.0016 (6)	0.0008 (6)	0.0056 (6)
C5	0.0198 (8)	0.0219 (8)	0.0205 (7)	−0.0014 (6)	0.0018 (6)	0.0025 (6)
C6	0.0202 (8)	0.0246 (8)	0.0217 (7)	−0.0009 (6)	0.0033 (6)	0.0008 (6)
C7	0.0206 (8)	0.0365 (9)	0.0298 (9)	−0.0008 (7)	0.0044 (6)	−0.0061 (7)
C8	0.0242 (9)	0.0277 (9)	0.0306 (9)	0.0022 (7)	0.0046 (7)	−0.0037 (7)
C9	0.0214 (8)	0.0255 (8)	0.0248 (8)	−0.0027 (6)	0.0034 (6)	−0.0015 (6)
C10	0.0186 (8)	0.0250 (8)	0.0180 (7)	−0.0007 (6)	0.0021 (6)	−0.0029 (6)
C11	0.0228 (8)	0.0285 (9)	0.0239 (8)	−0.0003 (7)	0.0009 (6)	0.0007 (7)
C12	0.0203 (8)	0.0426 (10)	0.0271 (9)	0.0060 (7)	−0.0002 (6)	−0.0023 (7)
C13	0.0160 (8)	0.0494 (11)	0.0265 (8)	−0.0053 (7)	0.0036 (6)	−0.0102 (8)
C14	0.0267 (9)	0.0336 (9)	0.0281 (9)	−0.0095 (7)	0.0080 (7)	−0.0065 (7)
C15	0.0228 (8)	0.0256 (8)	0.0246 (8)	−0.0022 (7)	0.0039 (6)	−0.0009 (7)
C16	0.0234 (9)	0.0353 (9)	0.0353 (9)	−0.0050 (7)	0.0071 (7)	−0.0142 (8)
C17	0.0189 (8)	0.0210 (8)	0.0260 (8)	−0.0042 (6)	−0.0011 (6)	0.0005 (7)
C18	0.0331 (10)	0.0334 (10)	0.0369 (10)	−0.0041 (8)	0.0037 (7)	−0.0119 (8)

Geometric parameters (Å, º) top

N1—C8	1.463 (2)	C7—H7B	0.9900
N1—C9	1.4618 (19)	C7—C8	1.514 (2)
N1—C18	1.4607 (19)	C8—H8A	0.9900
N2—C16	1.147 (2)	C8—H8B	0.9900
N3—C17	1.1483 (19)	C9—H9A	0.9900
N4—H4A	0.893 (12)	C9—H9B	0.9900
N4—H4B	0.874 (12)	C10—C11	1.394 (2)
N4—C2	1.3510 (19)	C10—C15	1.390 (2)
C1—C2	1.406 (2)	C11—H11	0.9500
C1—C6	1.406 (2)	C11—C12	1.388 (2)
C1—C16	1.436 (2)	C12—H12	0.9500
C2—C3	1.415 (2)	C12—C13	1.380 (2)
C3—C4	1.405 (2)	C13—H13	0.9500
C3—C17	1.439 (2)	C13—C14	1.381 (2)
C4—C5	1.405 (2)	C14—H14	0.9500
C4—C10	1.4931 (19)	C14—C15	1.387 (2)
C5—C6	1.394 (2)	C15—H15	0.9500
C5—C9	1.510 (2)	C18—H18A	0.9800
C6—C7	1.509 (2)	C18—H18B	0.9800
C7—H7A	0.9900	C18—H18C	0.9800

C9—N1—C8	109.38 (12)	C7—C8—H8B	109.7
C18—N1—C8	110.60 (12)	H8A—C8—H8B	108.2
C18—N1—C9	109.63 (12)	N1—C9—C5	112.08 (12)
H4A—N4—H4B	115.4 (16)	N1—C9—H9A	109.2
C2—N4—H4A	120.3 (11)	N1—C9—H9B	109.2
C2—N4—H4B	124.1 (11)	C5—C9—H9A	109.2
C2—C1—C16	118.09 (14)	C5—C9—H9B	109.2
C6—C1—C2	122.51 (14)	H9A—C9—H9B	107.9
C6—C1—C16	119.40 (14)	C11—C10—C4	120.20 (13)
N4—C2—C1	122.05 (14)	C15—C10—C4	120.79 (13)
N4—C2—C3	121.70 (14)	C15—C10—C11	119.01 (14)
C1—C2—C3	116.25 (13)	C10—C11—H11	119.9
C2—C3—C17	117.18 (13)	C12—C11—C10	120.30 (15)
C4—C3—C2	122.01 (13)	C12—C11—H11	119.9
C4—C3—C17	120.65 (13)	C11—C12—H12	119.9
C3—C4—C5	120.01 (13)	C13—C12—C11	120.15 (15)
C3—C4—C10	118.59 (13)	C13—C12—H12	119.9
C5—C4—C10	121.39 (13)	C12—C13—H13	120.0
C4—C5—C9	120.75 (13)	C12—C13—C14	120.00 (15)
C6—C5—C4	119.25 (13)	C14—C13—H13	120.0
C6—C5—C9	120.00 (13)	C13—C14—H14	119.9
C1—C6—C7	118.93 (13)	C13—C14—C15	120.17 (15)
C5—C6—C1	119.93 (13)	C15—C14—H14	119.9
C5—C6—C7	121.13 (13)	C10—C15—H15	119.8
C6—C7—H7A	109.2	C14—C15—C10	120.37 (15)
C6—C7—H7B	109.2	C14—C15—H15	119.8
C6—C7—C8	111.98 (13)	N2—C16—C1	178.82 (19)
H7A—C7—H7B	107.9	N3—C17—C3	175.71 (15)
C8—C7—H7A	109.2	N1—C18—H18A	109.5
C8—C7—H7B	109.2	N1—C18—H18B	109.5
N1—C8—C7	109.66 (13)	N1—C18—H18C	109.5
N1—C8—H8A	109.7	H18A—C18—H18B	109.5
N1—C8—H8B	109.7	H18A—C18—H18C	109.5
C7—C8—H8A	109.7	H18B—C18—H18C	109.5

N4—C2—C3—C4	−179.53 (14)	C6—C1—C2—C3	−1.3 (2)
N4—C2—C3—C17	−4.0 (2)	C6—C1—C16—N2	147 (9)
C1—C2—C3—C4	−0.3 (2)	C6—C5—C9—N1	−20.08 (19)
C1—C2—C3—C17	175.24 (13)	C6—C7—C8—N1	46.68 (18)
C1—C6—C7—C8	167.68 (14)	C8—N1—C9—C5	54.58 (16)
C2—C1—C6—C5	1.8 (2)	C9—N1—C8—C7	−69.32 (16)
C2—C1—C6—C7	−178.69 (14)	C9—C5—C6—C1	179.00 (13)
C2—C1—C16—N2	−34 (9)	C9—C5—C6—C7	−0.5 (2)
C2—C3—C4—C5	1.3 (2)	C10—C4—C5—C6	179.26 (13)
C2—C3—C4—C10	−178.81 (13)	C10—C4—C5—C9	−0.3 (2)
C2—C3—C17—N3	−19 (2)	C10—C11—C12—C13	0.3 (2)
C3—C4—C5—C6	−0.9 (2)	C11—C10—C15—C14	0.1 (2)
C3—C4—C5—C9	179.50 (13)	C11—C12—C13—C14	−0.3 (2)
C3—C4—C10—C11	61.30 (18)	C12—C13—C14—C15	0.1 (2)
C3—C4—C10—C15	−118.16 (16)	C13—C14—C15—C10	0.0 (2)
C4—C3—C17—N3	157 (2)	C15—C10—C11—C12	−0.2 (2)
C4—C5—C6—C1	−0.6 (2)	C16—C1—C2—N4	−1.3 (2)
C4—C5—C6—C7	179.86 (13)	C16—C1—C2—C3	179.48 (14)
C4—C5—C9—N1	159.53 (13)	C16—C1—C6—C5	−179.03 (14)
C4—C10—C11—C12	−179.67 (14)	C16—C1—C6—C7	0.5 (2)
C4—C10—C15—C14	179.53 (13)	C17—C3—C4—C5	−173.99 (13)
C5—C4—C10—C11	−118.85 (16)	C17—C3—C4—C10	5.9 (2)
C5—C4—C10—C15	61.68 (19)	C18—N1—C8—C7	169.84 (13)
C5—C6—C7—C8	−12.8 (2)	C18—N1—C9—C5	176.02 (13)
C6—C1—C2—N4	177.97 (15)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4A···N2ⁱ	0.89 (1)	2.21 (1)	3.052 (2)	157 (2)
N4—H4B···N1ⁱⁱ	0.87 (1)	2.21 (1)	3.0261 (19)	155 (2)

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

Experimental details

Crystal data
Chemical formula	C₁₈H₁₆N₄
M_r	288.35
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	143
a, b, c (Å)	17.5630 (5), 6.25208 (19), 13.7963 (4)
β (°)	93.209 (3)
V (Å³)	1512.53 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.38 × 0.35 × 0.25

Data collection
Diffractometer	Agilent Xcalibur Eos diffractometer
Absorption correction	Multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)
T_min, T_max	0.960, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	6799, 3089, 2414
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.112, 1.05
No. of reflections	3089
No. of parameters	206
No. of restraints	4
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.22

Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008), OLEX2 (Dolomanov et al., 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4A···N2ⁱ	0.893 (12)	2.210 (13)	3.052 (2)	157.1 (15)
N4—H4B···N1ⁱⁱ	0.874 (12)	2.210 (13)	3.0261 (19)	155.3 (15)

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

Acknowledgements

We thank the Analytical and Testing Center of Sichuan University for the X-ray measurements.

References

Balamurugan, K., Jeyachandran, V., Perumal, S. & Menéndez, J. C. (2011). Tetrahedron, 67, 1432–1437. Web of Science CSD CrossRef CAS Google Scholar
Cho, W.-J., Le, Q. M., Van, H. T. M., Lee, K. Y., Kang, B. Y., Lee, E.-S., Lee, S. K. & Kwon, Y. (2007). Bioorg. Med. Chem. Lett. 17, 3531–3534. Web of Science CrossRef PubMed CAS Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CrossRef CAS IUCr Journals Google Scholar
Marchand, C., Antony, S., Kohn, K. W., Cushman, M., Ioanoviciu, A., Staker, B. L., Burgin, A. B., Stewart, L. & Pommier, Y. (2006). Mol. Cancer Ther. 5, 287–295. Web of Science CrossRef PubMed CAS Google Scholar
Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction, Yarnton, England. Google Scholar
Rong, L. C., Gao, L. J., Han, H. X., Jiang, H., Dai, Y. S. & Tu, S. J. (2010). Synth. Commun. 40, 289–294. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Van Quaquebeke, E., Mahieu, T., Dumont, P., Dewelle, J., Ribaucour, F., Simon, G., Sauvage, S., Gaussin, J.-F., Tuti, J., El Yazidi, M., Van Vynckt, F., Mijatovic, T., Lefranc, F., Darro, F. & Kiss, R. (2007). J. Med. Chem. 50, 4122–4134. Web of Science CrossRef PubMed CAS Google Scholar