Ethyl 2,4-dimethyl-pyrido[1,2-a]benz-imidazole-3-carboxyl-ate.

The title compound, C(16)H(16)N(2)O(2), was synthesized using a novel tandem annulation reaction between 1-(1H-benzo[d]imidazol-2-yl)ethanone and ethyl (E)-4-bromo-but-2-enoate under mild conditions. The dihedral angles formed by the mean plane of the five-membered imidazole ring with the dihydro-pyridin and benzene rings are 1.54 (9) and 1.85 (9)°, respectively.

Related literature

For the synthesis and characterization of pyrido[1,2-a]benz­imidazole derivatives, see: Ge et al. (2009 ▶, 2011 ▶). For pharmaceutical applications of nitro­gen-containing heterocyclic compounds, see: Badawey & Kappe (1999 ▶).

Experimental

Crystal data

C16H16N2O2

M = 268.31

Monoclinic,

a = 7.671 (4) Å

b = 13.174 (7) Å

c = 13.807 (7) Å

β = 102.680 (7)°

V = 1361.3 (12) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 273 K

0.32 × 0.28 × 0.26 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.973, T max = 0.978

6894 measured reflections

2389 independent reflections

2056 reflections with I > 2σ(I)

R int = 0.086

Refinement

R[F 2 > 2σ(F 2)] = 0.047

wR(F 2) = 0.134

S = 1.05

2389 reflections

184 parameters

H-atom parameters constrained

Δρmax = 0.23 e Å−3

Δρmin = −0.26 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812040299/rz5006sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812040299/rz5006Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812040299/rz5006Isup3.cml

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

C16H16N2O2	F(000) = 568
Mr = 268.31	Dx = 1.309 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4261 reflections
a = 7.671 (4) Å	θ = 3.0–28.2°
b = 13.174 (7) Å	µ = 0.09 mm−1
c = 13.807 (7) Å	T = 273 K
β = 102.680 (7)°	Block, colourless
V = 1361.3 (12) Å3	0.32 × 0.28 × 0.26 mm
Z = 4

Bruker SMART APEXII CCD area-detector diffractometer	2389 independent reflections
Radiation source: fine-focus sealed tube	2056 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.086
phi and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −5→9
Tmin = 0.973, Tmax = 0.978	k = −15→14
6894 measured reflections	l = −16→16

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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.134	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.075P)2 + 0.2415P] where P = (Fo2 + 2Fc2)/3
2389 reflections	(Δ/σ)max = 0.052
184 parameters	Δρmax = 0.23 e Å−3
0 restraints	Δρmin = −0.26 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
N1	0.75792 (18)	−0.01609 (10)	0.27023 (9)	0.0440 (4)
N2	0.72152 (15)	−0.05514 (9)	0.10717 (9)	0.0351 (3)
O1	1.03253 (17)	0.23943 (10)	−0.01104 (10)	0.0594 (4)
O2	0.80757 (16)	0.30461 (8)	0.04828 (9)	0.0487 (3)
C1	0.7586 (4)	0.47805 (16)	0.07813 (19)	0.0802 (7)
H1A	0.6335	0.4681	0.0505	0.120*
H1B	0.7907	0.5467	0.0664	0.120*
H1C	0.7830	0.4654	0.1483	0.120*
C2	0.8641 (3)	0.40713 (12)	0.03063 (14)	0.0531 (5)
H2A	0.8429	0.4204	−0.0401	0.064*
H2B	0.9906	0.4155	0.0590	0.064*
C3	0.9069 (2)	0.22855 (11)	0.02743 (11)	0.0400 (4)
C4	0.84263 (19)	0.12847 (11)	0.05743 (10)	0.0365 (4)
C5	0.78468 (19)	0.05213 (11)	−0.01807 (10)	0.0360 (4)
C6	0.72718 (19)	−0.03754 (12)	0.00956 (10)	0.0373 (4)
H6	0.6910	−0.0881	−0.0376	0.045*
C7	0.77753 (19)	0.01635 (11)	0.18186 (10)	0.0358 (3)
C8	0.84377 (19)	0.11132 (11)	0.15597 (11)	0.0376 (4)
C9	0.9153 (2)	0.18433 (13)	0.23890 (12)	0.0505 (4)
H9A	1.0014	0.2284	0.2196	0.076*
H9B	0.9714	0.1471	0.2972	0.076*
H9C	0.8189	0.2241	0.2529	0.076*
C10	0.7900 (2)	0.07044 (13)	−0.12539 (11)	0.0460 (4)
H10A	0.7427	0.0123	−0.1643	0.069*
H10B	0.9113	0.0816	−0.1306	0.069*
H10C	0.7194	0.1291	−0.1495	0.069*
C11	0.66408 (19)	−0.13957 (11)	0.15187 (11)	0.0377 (4)
C12	0.6866 (2)	−0.11231 (12)	0.25233 (11)	0.0410 (4)
C13	0.6335 (2)	−0.18090 (14)	0.31784 (13)	0.0527 (5)
H13	0.6463	−0.1652	0.3847	0.063*
C14	0.5616 (2)	−0.27222 (14)	0.28027 (14)	0.0566 (5)
H14	0.5252	−0.3183	0.3229	0.068*
C15	0.5415 (2)	−0.29809 (13)	0.17999 (14)	0.0551 (5)
H15	0.4928	−0.3607	0.1577	0.066*
C16	0.5929 (2)	−0.23193 (12)	0.11366 (13)	0.0473 (4)
H16	0.5805	−0.2484	0.0470	0.057*

	U11	U22	U33	U12	U13	U23
N1	0.0471 (8)	0.0517 (8)	0.0327 (7)	−0.0038 (6)	0.0078 (5)	0.0015 (6)
N2	0.0331 (6)	0.0393 (7)	0.0329 (6)	0.0012 (5)	0.0070 (5)	−0.0004 (5)
O1	0.0582 (8)	0.0569 (7)	0.0723 (9)	−0.0017 (6)	0.0340 (7)	0.0058 (6)
O2	0.0493 (7)	0.0397 (6)	0.0601 (7)	0.0010 (5)	0.0186 (5)	0.0031 (5)
C1	0.0948 (17)	0.0504 (11)	0.1022 (18)	0.0057 (11)	0.0363 (14)	−0.0058 (11)
C2	0.0638 (11)	0.0409 (9)	0.0546 (10)	−0.0031 (8)	0.0126 (8)	0.0046 (8)
C3	0.0396 (8)	0.0440 (9)	0.0363 (8)	0.0011 (7)	0.0080 (6)	0.0016 (6)
C4	0.0319 (7)	0.0413 (8)	0.0366 (8)	0.0036 (6)	0.0085 (6)	0.0005 (6)
C5	0.0321 (7)	0.0438 (8)	0.0324 (7)	0.0057 (6)	0.0074 (6)	0.0000 (6)
C6	0.0366 (8)	0.0432 (8)	0.0314 (7)	0.0027 (6)	0.0055 (6)	−0.0043 (6)
C7	0.0333 (7)	0.0421 (8)	0.0318 (7)	0.0019 (6)	0.0064 (6)	−0.0017 (6)
C8	0.0355 (8)	0.0409 (8)	0.0360 (8)	0.0017 (6)	0.0069 (6)	−0.0024 (6)
C9	0.0584 (10)	0.0523 (10)	0.0397 (9)	−0.0096 (8)	0.0084 (7)	−0.0069 (7)
C10	0.0473 (9)	0.0566 (10)	0.0345 (8)	0.0042 (7)	0.0097 (7)	0.0030 (7)
C11	0.0311 (7)	0.0401 (8)	0.0419 (8)	0.0032 (6)	0.0081 (6)	0.0046 (6)
C12	0.0352 (8)	0.0488 (9)	0.0380 (8)	0.0030 (6)	0.0057 (6)	0.0067 (6)
C13	0.0480 (10)	0.0654 (11)	0.0432 (9)	−0.0023 (8)	0.0067 (7)	0.0143 (8)
C14	0.0476 (10)	0.0582 (11)	0.0622 (11)	−0.0028 (8)	0.0085 (8)	0.0237 (9)
C15	0.0480 (10)	0.0450 (9)	0.0711 (12)	−0.0029 (7)	0.0105 (8)	0.0066 (8)
C16	0.0449 (9)	0.0444 (9)	0.0534 (10)	−0.0003 (7)	0.0124 (7)	−0.0015 (7)

N1—C7	1.332 (2)	C6—H6	0.9300
N1—C12	1.381 (2)	C7—C8	1.425 (2)
N2—C6	1.3775 (19)	C8—C9	1.504 (2)
N2—C11	1.3899 (19)	C9—H9A	0.9600
N2—C7	1.393 (2)	C9—H9B	0.9600
O1—C3	1.2065 (19)	C9—H9C	0.9600
O2—C3	1.3283 (19)	C10—H10A	0.9600
O2—C2	1.455 (2)	C10—H10B	0.9600
C1—C2	1.480 (3)	C10—H10C	0.9600
C1—H1A	0.9600	C11—C16	1.389 (2)
C1—H1B	0.9600	C11—C12	1.406 (2)
C1—H1C	0.9600	C12—C13	1.401 (2)
C2—H2A	0.9700	C13—C14	1.377 (3)
C2—H2B	0.9700	C13—H13	0.9300
C3—C4	1.498 (2)	C14—C15	1.401 (3)
C4—C8	1.377 (2)	C14—H14	0.9300
C4—C5	1.446 (2)	C15—C16	1.383 (2)
C5—C6	1.345 (2)	C15—H15	0.9300
C5—C10	1.511 (2)	C16—H16	0.9300
C7—N1—C12	104.51 (12)	C4—C8—C9	124.71 (14)
C6—N2—C11	130.57 (13)	C7—C8—C9	117.46 (13)
C6—N2—C7	122.66 (13)	C8—C9—H9A	109.5
C11—N2—C7	106.78 (12)	C8—C9—H9B	109.5
C3—O2—C2	117.24 (13)	H9A—C9—H9B	109.5
C2—C1—H1A	109.5	C8—C9—H9C	109.5
C2—C1—H1B	109.5	H9A—C9—H9C	109.5
H1A—C1—H1B	109.5	H9B—C9—H9C	109.5
C2—C1—H1C	109.5	C5—C10—H10A	109.5
H1A—C1—H1C	109.5	C5—C10—H10B	109.5
H1B—C1—H1C	109.5	H10A—C10—H10B	109.5
O2—C2—C1	107.44 (15)	C5—C10—H10C	109.5
O2—C2—H2A	110.2	H10A—C10—H10C	109.5
C1—C2—H2A	110.2	H10B—C10—H10C	109.5
O2—C2—H2B	110.2	C16—C11—N2	131.97 (15)
C1—C2—H2B	110.2	C16—C11—C12	123.44 (14)
H2A—C2—H2B	108.5	N2—C11—C12	104.56 (13)
O1—C3—O2	123.88 (14)	N1—C12—C13	129.53 (15)
O1—C3—C4	124.72 (14)	N1—C12—C11	111.65 (13)
O2—C3—C4	111.39 (13)	C13—C12—C11	118.81 (15)
C8—C4—C5	122.15 (14)	C14—C13—C12	118.01 (17)
C8—C4—C3	119.11 (13)	C14—C13—H13	121.0
C5—C4—C3	118.72 (13)	C12—C13—H13	121.0
C6—C5—C4	118.31 (14)	C13—C14—C15	122.22 (16)
C6—C5—C10	119.97 (14)	C13—C14—H14	118.9
C4—C5—C10	121.71 (14)	C15—C14—H14	118.9
C5—C6—N2	120.53 (13)	C16—C15—C14	121.04 (17)
C5—C6—H6	119.7	C16—C15—H15	119.5
N2—C6—H6	119.7	C14—C15—H15	119.5
N1—C7—N2	112.50 (13)	C15—C16—C11	116.48 (16)
N1—C7—C8	129.02 (14)	C15—C16—H16	121.8
N2—C7—C8	118.48 (13)	C11—C16—H16	121.8
C4—C8—C7	117.80 (13)