3-[(1-Isobutyl-1H-imidazo[4,5-c]quinolin-4-yl)amino]-benzoic acid.

In the title compound, C(21)H(20)N(4)O(2), the statistically planar 1H-limidazole ring [maximum deviation = 0.003 (1) Å] makes dihedral angles of 1.33 (9) and 8.23 (7)°, respectively, with the essentially planar fused pyridine ring [maximum devation = 0.018 (1) Å] and the pendant benzene ring, which is attached to the pyridine ring by an -NH- group. An intra-molecular C-H⋯N inter-action, which generates an S(6) ring, helps to estalish the mol-ecular conformation. In the crystal, the mol-ecules are linked by N-H⋯O, C-H⋯O and O-H-N hydrogen bonds, which generate bifurcated R(1) (2)(6) and R(2) (2)(9) ring motifs, resulting in supra-molecular [001] chains. The crystal structure also features weak π-π stacking [centroid-centroid distance = 3.5943 (9) Å] and C-H⋯π inter-actions.

Related literature

For our previous study of a related structure and background references, see: Loh et al. (2011 ▶). For a further related structure, see: Rasmussen et al. (2009 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For reference bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C21H20N4O2

M = 360.41

Monoclinic,

a = 9.6440 (1) Å

b = 15.1496 (2) Å

c = 14.5286 (2) Å

β = 123.927 (1)°

V = 1761.28 (4) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 296 K

0.41 × 0.26 × 0.22 mm

Data collection

Bruker APEXII DUO CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T min = 0.964, T max = 0.980

23777 measured reflections

5859 independent reflections

4504 reflections with I > 2σ(I)

R int = 0.035

Refinement

R[F 2 > 2σ(F 2)] = 0.051

wR(F 2) = 0.140

S = 1.04

5859 reflections

254 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.51 e Å−3

Δρmin = −0.22 e Å−3

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) ▶.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811028765/hb5954sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811028765/hb5954Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811028765/hb5954Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C21H20N4O2	F(000) = 760
Mr = 360.41	Dx = 1.359 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5489 reflections
a = 9.6440 (1) Å	θ = 2.2–32.1°
b = 15.1496 (2) Å	µ = 0.09 mm−1
c = 14.5286 (2) Å	T = 296 K
β = 123.927 (1)°	Block, colourless
V = 1761.28 (4) Å3	0.41 × 0.26 × 0.22 mm
Z = 4

Bruker APEXII DUO CCD diffractometer	5859 independent reflections
Radiation source: fine-focus sealed tube	4504 reflections with I > 2σ(I)
graphite	Rint = 0.035
φ and ω scans	θmax = 31.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −13→14
Tmin = 0.964, Tmax = 0.980	k = −20→22
23777 measured reflections	l = −21→18

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.140	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ2(Fo2) + (0.0764P)2 + 0.3392P] where P = (Fo2 + 2Fc2)/3
5859 reflections	(Δ/σ)max < 0.001
254 parameters	Δρmax = 0.51 e Å−3
0 restraints	Δρmin = −0.22 e Å−3

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.

	x	y	z	Uiso*/Ueq
O1	0.14729 (12)	−0.33971 (6)	0.12947 (8)	0.0215 (2)
O2	0.15417 (11)	−0.47845 (6)	0.18402 (7)	0.01792 (19)
N1	0.16268 (13)	−0.15414 (6)	0.43284 (9)	0.0156 (2)
N2	0.24570 (13)	−0.09564 (6)	0.32204 (8)	0.0155 (2)
N3	0.33813 (12)	0.13649 (6)	0.49615 (8)	0.0148 (2)
N4	0.22805 (13)	0.02550 (7)	0.53736 (8)	0.0153 (2)
C1	0.07884 (15)	−0.42262 (8)	0.33507 (10)	0.0170 (2)
H1A	0.0624	−0.4821	0.3160	0.020*
C2	0.05934 (17)	−0.39045 (8)	0.41686 (11)	0.0206 (3)
H2A	0.0269	−0.4287	0.4516	0.025*
C3	0.08756 (16)	−0.30209 (8)	0.44747 (10)	0.0188 (2)
H3A	0.0752	−0.2822	0.5030	0.023*
C4	0.13454 (14)	−0.24239 (7)	0.39563 (10)	0.0142 (2)
C5	0.15066 (14)	−0.27426 (8)	0.31152 (9)	0.0142 (2)
H5A	0.1794	−0.2358	0.2748	0.017*
C6	0.12366 (14)	−0.36354 (7)	0.28254 (9)	0.0136 (2)
C7	0.14233 (14)	−0.39209 (8)	0.19153 (9)	0.0144 (2)
C8	0.21835 (14)	−0.08493 (7)	0.40042 (9)	0.0141 (2)
C9	0.30995 (14)	−0.02752 (8)	0.29402 (10)	0.0149 (2)
C10	0.33503 (16)	−0.04493 (8)	0.20876 (10)	0.0190 (2)
H10A	0.3056	−0.0997	0.1740	0.023*
C11	0.40222 (16)	0.01784 (8)	0.17665 (11)	0.0207 (3)
H11A	0.4170	0.0056	0.1199	0.025*
C12	0.44865 (16)	0.10040 (8)	0.22899 (11)	0.0198 (2)
H12A	0.4963	0.1422	0.2078	0.024*
C13	0.42430 (15)	0.12010 (8)	0.31138 (10)	0.0173 (2)
H13A	0.4547	0.1753	0.3451	0.021*
C14	0.35331 (14)	0.05705 (8)	0.34531 (9)	0.0143 (2)
C15	0.31713 (14)	0.06692 (7)	0.42760 (9)	0.0135 (2)
C16	0.24962 (14)	−0.00111 (8)	0.45501 (9)	0.0139 (2)
C17	0.28305 (15)	0.10753 (8)	0.55894 (10)	0.0163 (2)
H17A	0.2841	0.1423	0.6121	0.020*
C18	0.41403 (15)	0.22270 (8)	0.50622 (10)	0.0168 (2)
H18A	0.5132	0.2142	0.5056	0.020*
H18B	0.4490	0.2484	0.5772	0.020*
C19	0.29783 (15)	0.28790 (8)	0.41406 (10)	0.0175 (2)
H19A	0.2461	0.2576	0.3425	0.021*
C20	0.40172 (18)	0.36485 (9)	0.41590 (13)	0.0277 (3)
H20A	0.4829	0.3431	0.4029	0.041*
H20B	0.4579	0.3934	0.4869	0.041*
H20C	0.3297	0.4064	0.3590	0.041*
C21	0.15965 (15)	0.31946 (8)	0.42709 (11)	0.0211 (3)
H21A	0.0850	0.3575	0.3663	0.032*
H21B	0.2080	0.3513	0.4956	0.032*
H21C	0.0989	0.2695	0.4276	0.032*
H1N1	0.1529 (19)	−0.1435 (11)	0.4871 (14)	0.021 (4)*
H1O2	0.171 (3)	−0.4938 (15)	0.1246 (18)	0.052 (6)*

	U11	U22	U33	U12	U13	U23
O1	0.0341 (5)	0.0166 (4)	0.0218 (5)	0.0039 (4)	0.0207 (4)	0.0028 (3)
O2	0.0250 (4)	0.0134 (4)	0.0200 (4)	0.0004 (3)	0.0155 (4)	−0.0017 (3)
N1	0.0232 (5)	0.0119 (4)	0.0170 (5)	−0.0023 (4)	0.0145 (4)	−0.0020 (3)
N2	0.0192 (5)	0.0131 (5)	0.0163 (5)	0.0004 (4)	0.0112 (4)	0.0007 (3)
N3	0.0184 (5)	0.0110 (4)	0.0150 (5)	−0.0013 (3)	0.0094 (4)	−0.0002 (3)
N4	0.0184 (5)	0.0141 (5)	0.0147 (4)	−0.0001 (3)	0.0100 (4)	0.0003 (3)
C1	0.0215 (5)	0.0135 (5)	0.0182 (5)	−0.0030 (4)	0.0125 (5)	−0.0018 (4)
C2	0.0298 (6)	0.0166 (6)	0.0220 (6)	−0.0062 (5)	0.0186 (5)	−0.0018 (4)
C3	0.0265 (6)	0.0170 (6)	0.0200 (6)	−0.0043 (4)	0.0174 (5)	−0.0031 (4)
C4	0.0149 (5)	0.0123 (5)	0.0148 (5)	−0.0012 (4)	0.0079 (4)	−0.0009 (4)
C5	0.0162 (5)	0.0125 (5)	0.0151 (5)	−0.0001 (4)	0.0094 (4)	0.0002 (4)
C6	0.0145 (5)	0.0135 (5)	0.0130 (5)	0.0005 (4)	0.0077 (4)	−0.0002 (4)
C7	0.0136 (5)	0.0143 (5)	0.0146 (5)	0.0008 (4)	0.0074 (4)	−0.0017 (4)
C8	0.0153 (5)	0.0119 (5)	0.0144 (5)	−0.0002 (4)	0.0078 (4)	0.0006 (4)
C9	0.0160 (5)	0.0141 (5)	0.0149 (5)	0.0015 (4)	0.0087 (4)	0.0020 (4)
C10	0.0236 (6)	0.0170 (6)	0.0196 (6)	0.0031 (4)	0.0141 (5)	0.0015 (4)
C11	0.0257 (6)	0.0214 (6)	0.0198 (6)	0.0050 (5)	0.0158 (5)	0.0049 (5)
C12	0.0207 (6)	0.0195 (6)	0.0226 (6)	0.0030 (4)	0.0143 (5)	0.0073 (5)
C13	0.0177 (5)	0.0153 (5)	0.0192 (6)	0.0008 (4)	0.0106 (5)	0.0033 (4)
C14	0.0140 (5)	0.0142 (5)	0.0142 (5)	0.0014 (4)	0.0077 (4)	0.0023 (4)
C15	0.0145 (5)	0.0112 (5)	0.0140 (5)	0.0004 (4)	0.0075 (4)	0.0003 (4)
C16	0.0155 (5)	0.0131 (5)	0.0134 (5)	0.0008 (4)	0.0082 (4)	0.0006 (4)
C17	0.0209 (5)	0.0138 (5)	0.0155 (5)	−0.0009 (4)	0.0111 (5)	−0.0005 (4)
C18	0.0182 (5)	0.0119 (5)	0.0189 (6)	−0.0029 (4)	0.0094 (5)	−0.0003 (4)
C19	0.0194 (5)	0.0134 (5)	0.0197 (6)	0.0002 (4)	0.0109 (5)	0.0022 (4)
C20	0.0284 (7)	0.0178 (6)	0.0411 (8)	0.0009 (5)	0.0220 (6)	0.0083 (5)
C21	0.0194 (6)	0.0175 (6)	0.0245 (6)	−0.0001 (4)	0.0111 (5)	−0.0006 (5)

O1—C7	1.2219 (15)	C9—C10	1.4131 (17)
O2—C7	1.3231 (14)	C9—C14	1.4225 (16)
O2—H1O2	0.99 (2)	C10—C11	1.3709 (18)
N1—C8	1.3755 (15)	C10—H10A	0.9300
N1—C4	1.4106 (15)	C11—C12	1.4012 (18)
N1—H1N1	0.860 (16)	C11—H11A	0.9300
N2—C8	1.3145 (15)	C12—C13	1.3750 (18)
N2—C9	1.3771 (15)	C12—H12A	0.9300
N3—C17	1.3592 (15)	C13—C14	1.4146 (16)
N3—C15	1.3852 (14)	C13—H13A	0.9300
N3—C18	1.4641 (15)	C14—C15	1.4280 (17)
N4—C17	1.3185 (15)	C15—C16	1.3907 (16)
N4—C16	1.3838 (15)	C17—H17A	0.9300
C1—C2	1.3908 (17)	C18—C19	1.5327 (16)
C1—C6	1.3923 (16)	C18—H18A	0.9700
C1—H1A	0.9300	C18—H18B	0.9700
C2—C3	1.3887 (17)	C19—C21	1.5238 (18)
C2—H2A	0.9300	C19—C20	1.5276 (18)
C3—C4	1.4041 (16)	C19—H19A	0.9800
C3—H3A	0.9300	C20—H20A	0.9600
C4—C5	1.4008 (16)	C20—H20B	0.9600
C5—C6	1.3973 (16)	C20—H20C	0.9600
C5—H5A	0.9300	C21—H21A	0.9600
C6—C7	1.4945 (16)	C21—H21B	0.9600
C8—C16	1.4371 (16)	C21—H21C	0.9600
C7—O2—H1O2	111.6 (13)	C13—C12—C11	120.54 (11)
C8—N1—C4	128.29 (10)	C13—C12—H12A	119.7
C8—N1—H1N1	115.8 (11)	C11—C12—H12A	119.7
C4—N1—H1N1	115.7 (11)	C12—C13—C14	120.52 (11)
C8—N2—C9	120.30 (10)	C12—C13—H13A	119.7
C17—N3—C15	106.38 (10)	C14—C13—H13A	119.7
C17—N3—C18	125.57 (10)	C13—C14—C9	118.92 (11)
C15—N3—C18	127.95 (10)	C13—C14—C15	127.81 (11)
C17—N4—C16	104.21 (10)	C9—C14—C15	113.27 (10)
C2—C1—C6	118.33 (11)	N3—C15—C16	105.18 (10)
C2—C1—H1A	120.8	N3—C15—C14	132.51 (11)
C6—C1—H1A	120.8	C16—C15—C14	122.30 (10)
C3—C2—C1	121.03 (11)	N4—C16—C15	110.61 (10)
C3—C2—H2A	119.5	N4—C16—C8	130.39 (11)
C1—C2—H2A	119.5	C15—C16—C8	118.97 (11)
C2—C3—C4	120.89 (11)	N4—C17—N3	113.62 (11)
C2—C3—H3A	119.6	N4—C17—H17A	123.2
C4—C3—H3A	119.6	N3—C17—H17A	123.2
C5—C4—C3	118.17 (11)	N3—C18—C19	113.99 (10)
C5—C4—N1	124.73 (10)	N3—C18—H18A	108.8
C3—C4—N1	117.10 (11)	C19—C18—H18A	108.8
C6—C5—C4	120.25 (11)	N3—C18—H18B	108.8
C6—C5—H5A	119.9	C19—C18—H18B	108.8
C4—C5—H5A	119.9	H18A—C18—H18B	107.6
C1—C6—C5	121.31 (11)	C21—C19—C20	111.64 (11)
C1—C6—C7	121.77 (10)	C21—C19—C18	110.94 (10)
C5—C6—C7	116.91 (10)	C20—C19—C18	108.90 (10)
O1—C7—O2	122.72 (11)	C21—C19—H19A	108.4
O1—C7—C6	122.59 (10)	C20—C19—H19A	108.4
O2—C7—C6	114.69 (10)	C18—C19—H19A	108.4
N2—C8—N1	120.53 (10)	C19—C20—H20A	109.5
N2—C8—C16	120.36 (10)	C19—C20—H20B	109.5
N1—C8—C16	119.10 (10)	H20A—C20—H20B	109.5
N2—C9—C10	116.40 (11)	C19—C20—H20C	109.5
N2—C9—C14	124.70 (11)	H20A—C20—H20C	109.5
C10—C9—C14	118.89 (11)	H20B—C20—H20C	109.5
C11—C10—C9	120.90 (12)	C19—C21—H21A	109.5
C11—C10—H10A	119.6	C19—C21—H21B	109.5
C9—C10—H10A	119.6	H21A—C21—H21B	109.5
C10—C11—C12	120.20 (12)	C19—C21—H21C	109.5
C10—C11—H11A	119.9	H21A—C21—H21C	109.5
C12—C11—H11A	119.9	H21B—C21—H21C	109.5
C6—C1—C2—C3	−1.50 (19)	N2—C9—C14—C13	177.58 (11)
C1—C2—C3—C4	0.8 (2)	C10—C9—C14—C13	−1.70 (16)
C2—C3—C4—C5	0.58 (18)	N2—C9—C14—C15	−2.51 (16)
C2—C3—C4—N1	−179.23 (12)	C10—C9—C14—C15	178.21 (10)
C8—N1—C4—C5	−3.85 (19)	C17—N3—C15—C16	−0.25 (12)
C8—N1—C4—C3	175.94 (11)	C18—N3—C15—C16	176.10 (11)
C3—C4—C5—C6	−1.29 (17)	C17—N3—C15—C14	−179.22 (12)
N1—C4—C5—C6	178.50 (11)	C18—N3—C15—C14	−2.9 (2)
C2—C1—C6—C5	0.77 (18)	C13—C14—C15—N3	0.0 (2)
C2—C1—C6—C7	−178.19 (11)	C9—C14—C15—N3	−179.85 (11)
C4—C5—C6—C1	0.63 (17)	C13—C14—C15—C16	−178.78 (11)
C4—C5—C6—C7	179.64 (10)	C9—C14—C15—C16	1.32 (16)
C1—C6—C7—O1	164.52 (12)	C17—N4—C16—C15	−0.49 (13)
C5—C6—C7—O1	−14.48 (16)	C17—N4—C16—C8	177.45 (12)
C1—C6—C7—O2	−15.91 (16)	N3—C15—C16—N4	0.46 (13)
C5—C6—C7—O2	165.09 (10)	C14—C15—C16—N4	179.56 (10)
C9—N2—C8—N1	−176.50 (10)	N3—C15—C16—C8	−177.74 (10)
C9—N2—C8—C16	2.20 (16)	C14—C15—C16—C8	1.36 (17)
C4—N1—C8—N2	3.04 (18)	N2—C8—C16—N4	178.96 (11)
C4—N1—C8—C16	−175.68 (11)	N1—C8—C16—N4	−2.32 (18)
C8—N2—C9—C10	−179.91 (10)	N2—C8—C16—C15	−3.25 (16)
C8—N2—C9—C14	0.79 (17)	N1—C8—C16—C15	175.47 (10)
N2—C9—C10—C11	−178.40 (11)	C16—N4—C17—N3	0.33 (13)
C14—C9—C10—C11	0.94 (18)	C15—N3—C17—N4	−0.05 (13)
C9—C10—C11—C12	0.58 (19)	C18—N3—C17—N4	−176.51 (10)
C10—C11—C12—C13	−1.35 (19)	C17—N3—C18—C19	−104.71 (13)
C11—C12—C13—C14	0.55 (18)	C15—N3—C18—C19	79.60 (15)
C12—C13—C14—C9	0.97 (17)	N3—C18—C19—C21	71.13 (13)
C12—C13—C14—C15	−178.92 (11)	N3—C18—C19—C20	−165.62 (11)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O1i	0.860 (16)	2.114 (17)	2.9436 (14)	161.8 (15)
O2—H1O2···N4ii	0.99 (2)	1.71 (2)	2.6926 (13)	172 (2)
C3—H3A···O1i	0.93	2.42	3.1998 (15)	142
C5—H5A···N2	0.93	2.21	2.8337 (16)	123
C1—H1A···Cg2iii	0.93	2.94	3.3877 (14)	111

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N1⋯O1i	0.860 (16)	2.114 (17)	2.9436 (14)	161.8 (15)
O2—H1O2⋯N4ii	0.99 (2)	1.71 (2)	2.6926 (13)	172 (2)
C3—H3A⋯O1i	0.93	2.42	3.1998 (15)	142
C5—H5A⋯N2	0.93	2.21	2.8337 (16)	123
C1—H1A⋯Cg2iii	0.93	2.94	3.3877 (14)	111

Symmetry codes: (i) ; (ii) ; (iii) .