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The title compounds, 2-(4-bromophenyl)-1,2-dihydropyrimido[1,2-
a]benzimidazol-4-(3
H)-one, C
16H
12BrN
3O, (IV
a), and 4-(4-methylphenyl)-3,4-dihydropyrimido[1,2-
a]benzimidazol-2-(1
H)-one, C
17H
15N
3O, (V
b), both form
R(8) centrosymmetric dimers
via N—H
N hydrogen bonds. The N
N distance is 2.943 (3) Å for (IV
a) and 2.8481 (16) Å for (V
b), with the corresponding N—H
N angles being 129 and 167°, respectively. However, in other respects, the supramolecular structures of the two compounds differ. Both compounds contain different C—H
π interactions, in which the C—H
π(centroid) distances are 2.59 and 2.47 Å for (IV
a) and (V
b), respectively (the latter being a short distance), with C—H
π(centroid) angles of 158 and 159°, respectively. The supramolecular structures also differ, with a short Br
O distance of 3.117 (2) Å in bromo derivative (IV
a), and a C—H
O interaction with a C
O distance of 3.2561 (19) Å and a C—H
O angle of 127° in tolyl system (V
b). The dihydropyrimido part of (V
b) is disordered, with a ratio of the major and minor components of 0.9:0.1. The disorder consists of two non-interchangeable envelope conformers, each with an equatorial tolyl group and an axial methine H atom.
Supporting information
CCDC references: 182046; 182047
A solution of 2-aminobenzimidazole, (1) (2.0 mmoles), and an equimolar amount of
4-bromobenzaldehyde, (2a), or 4-tolualdehyde, (2 b), and Meldrum's acid, (3),
in ethanol (20 ml) was refluxed for 1–2 h with thin-layer chromatography
control. The solvent was then removed and the resulting precipitate was
filtered, washed with ethanol, dried and purified by silica gel chromatography
with ethyl acetate as the eluent. The title compounds were eluted in the order
(4) then (5) from the column. Colourless crystals suitable for X-ray
diffraction were obtained directly from the chromatographic fractions. (I):
20% yield, m.p. 577 K; (II): 69% yield, m.p. 506 K.
All H atoms were treated as riding, with C—H = 0.95 Å (phenyl H) for (I) and
1.00 Å (methine H) for (II). A residual electron density peak of 0.75 e Å-3 was found in the final stages of refinement for (II) at 1.2 Å from
C4A, 1.45 Å from C3 and 1.63 Å from N5. This suggested that two envelope
forms were present for the dihydropyrimido part of the molecule and it was
found that this was the case. Since the next difference map peaks were less
than 0.3 e Å-3, the nature of the disorder was not immediately obvious.
When atom C4B was put at the position of the difference map peak and atom C4A
and the attached tolyl group were refined with a free variable, such that the
combined site occupancy factors added up to 1.0, then a minor component
consisting of C4B and a staggered tolyl group overlapping the major component
tolyl group was found from the resulting difference map (Fig. 6). The minor
component was modelled using appropriate DFIX constraints to optimize
the position of C4B with respect to C4A, C3, N5 and C41B. ISOR and DELU
constraints were applied to the phenyl ring atoms of the minor component
(SHELXL97; Sheldrick, 1997). The ratio of major to minor components is
ca 0.9:0.1 and consists of two non-interchangeable conformers, each
with an axial tolyl group.
For both compounds, data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976) and PLATON (Spek, 2001); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
(IVa) 2-(4-Bromophenyl)-1,2-dihydropyrimido[1,2-
a]benzimidazol-4(3
H)-one
top
Crystal data top
C16H12BrN3O | F(000) = 688 |
Mr = 342.20 | Dx = 1.638 Mg m−3 |
Monoclinic, P21/c | Melting point: 577 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 6.8807 (2) Å | Cell parameters from 3046 reflections |
b = 16.2254 (6) Å | θ = 3.0–27.4° |
c = 13.3379 (5) Å | µ = 2.96 mm−1 |
β = 111.280 (2)° | T = 120 K |
V = 1387.54 (8) Å3 | Lath, colourless |
Z = 4 | 0.20 × 0.06 × 0.02 mm |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3046 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 2401 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.078 |
ϕ scans, and ω scans with κ offsets | θmax = 27.4°, θmin = 3.0° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −8→8 |
Tmin = 0.589, Tmax = 0.943 | k = −21→21 |
8697 measured reflections | l = −17→13 |
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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0658P)2] where P = (Fo2 + 2Fc2)/3 |
3046 reflections | (Δ/σ)max = 0.001 |
190 parameters | Δρmax = 0.71 e Å−3 |
0 restraints | Δρmin = −1.55 e Å−3 |
Crystal data top
C16H12BrN3O | V = 1387.54 (8) Å3 |
Mr = 342.20 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 6.8807 (2) Å | µ = 2.96 mm−1 |
b = 16.2254 (6) Å | T = 120 K |
c = 13.3379 (5) Å | 0.20 × 0.06 × 0.02 mm |
β = 111.280 (2)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3046 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 2401 reflections with I > 2σ(I) |
Tmin = 0.589, Tmax = 0.943 | Rint = 0.078 |
8697 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.71 e Å−3 |
3046 reflections | Δρmin = −1.55 e Å−3 |
190 parameters | |
Special details top
Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm
(Fox & Holmes, 1966) which effectively corrects for absorption effects.
High-redundancy data were used in the scaling program, hence the `multi-scan'
code-word was used. No transmission coefficients are available from the
program (only scale factors for each frame). The scale factors in the
experimental table are calculated from the SIZE command in the SHELXL97
input file. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
N1 | 0.8909 (4) | 0.40997 (15) | 0.06599 (19) | 0.0202 (5) | |
C2 | 0.8971 (5) | 0.36859 (17) | 0.1653 (2) | 0.0202 (6) | |
C21 | 0.7504 (5) | 0.41219 (17) | 0.2108 (2) | 0.0203 (6) | |
C22 | 0.5453 (5) | 0.43433 (17) | 0.1448 (3) | 0.0234 (7) | |
C23 | 0.4160 (5) | 0.47768 (19) | 0.1863 (2) | 0.0227 (6) | |
C24 | 0.4927 (4) | 0.49813 (17) | 0.2952 (2) | 0.0200 (6) | |
Br24 | 0.31283 (5) | 0.557959 (18) | 0.34998 (2) | 0.02561 (14) | |
C25 | 0.6932 (5) | 0.47610 (18) | 0.3619 (2) | 0.0226 (6) | |
C26 | 0.8204 (5) | 0.43347 (17) | 0.3187 (3) | 0.0232 (7) | |
C3 | 0.8401 (5) | 0.27790 (18) | 0.1389 (2) | 0.0227 (6) | |
C4 | 0.9671 (4) | 0.23567 (17) | 0.0811 (2) | 0.0206 (6) | |
O4 | 0.9921 (4) | 0.16254 (12) | 0.07701 (17) | 0.0271 (5) | |
N5 | 1.0538 (4) | 0.29104 (14) | 0.02729 (18) | 0.0174 (5) | |
C5A | 1.1695 (5) | 0.27315 (18) | −0.0394 (2) | 0.0196 (6) | |
C6 | 1.2800 (5) | 0.20374 (17) | −0.0502 (2) | 0.0224 (6) | |
C7 | 1.3886 (5) | 0.21007 (19) | −0.1201 (3) | 0.0256 (7) | |
C8 | 1.3865 (5) | 0.2825 (2) | −0.1770 (3) | 0.0276 (7) | |
C9 | 1.2770 (5) | 0.35229 (19) | −0.1643 (2) | 0.0239 (7) | |
C9A | 1.1727 (4) | 0.34733 (17) | −0.0929 (2) | 0.0197 (6) | |
N10 | 1.0655 (4) | 0.40985 (15) | −0.05954 (19) | 0.0190 (5) | |
C10A | 0.9990 (5) | 0.37510 (17) | 0.0111 (2) | 0.0181 (6) | |
H1 | 0.8194 | 0.4557 | 0.0435 | 0.024* | |
H2 | 1.0425 | 0.3718 | 0.2195 | 0.024* | |
H22 | 0.4943 | 0.4195 | 0.0709 | 0.028* | |
H23 | 0.2787 | 0.4929 | 0.1413 | 0.027* | |
H25 | 0.7430 | 0.4900 | 0.4361 | 0.027* | |
H26 | 0.9578 | 0.4187 | 0.3641 | 0.028* | |
H3A | 0.8608 | 0.2479 | 0.2067 | 0.027* | |
H3B | 0.6904 | 0.2742 | 0.0933 | 0.027* | |
H6 | 1.2812 | 0.1544 | −0.0117 | 0.027* | |
H7 | 1.4658 | 0.1640 | −0.1293 | 0.031* | |
H8 | 1.4601 | 0.2845 | −0.2250 | 0.033* | |
H9 | 1.2744 | 0.4014 | −0.2035 | 0.029* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0244 (14) | 0.0171 (12) | 0.0212 (13) | 0.0060 (11) | 0.0107 (11) | −0.0011 (10) |
C2 | 0.0209 (15) | 0.0196 (14) | 0.0209 (15) | −0.0006 (12) | 0.0082 (12) | 0.0019 (12) |
C21 | 0.0211 (16) | 0.0143 (13) | 0.0278 (16) | −0.0008 (12) | 0.0116 (13) | 0.0019 (12) |
C22 | 0.0274 (17) | 0.0238 (16) | 0.0206 (15) | −0.0036 (13) | 0.0105 (13) | −0.0053 (12) |
C23 | 0.0203 (15) | 0.0230 (15) | 0.0238 (15) | −0.0003 (13) | 0.0070 (12) | −0.0019 (13) |
C24 | 0.0235 (15) | 0.0162 (13) | 0.0244 (15) | −0.0013 (12) | 0.0135 (12) | −0.0012 (12) |
Br24 | 0.0305 (2) | 0.0222 (2) | 0.0303 (2) | 0.00089 (12) | 0.01833 (16) | −0.00318 (12) |
C25 | 0.0265 (16) | 0.0233 (15) | 0.0189 (14) | −0.0017 (14) | 0.0095 (12) | 0.0022 (12) |
C26 | 0.0237 (17) | 0.0204 (15) | 0.0260 (16) | 0.0013 (12) | 0.0096 (13) | 0.0052 (12) |
C3 | 0.0267 (16) | 0.0170 (14) | 0.0271 (16) | −0.0035 (13) | 0.0132 (13) | −0.0002 (13) |
C4 | 0.0235 (16) | 0.0162 (14) | 0.0212 (15) | 0.0006 (12) | 0.0072 (12) | 0.0002 (11) |
O4 | 0.0394 (13) | 0.0145 (10) | 0.0329 (12) | 0.0012 (9) | 0.0197 (10) | 0.0022 (9) |
N5 | 0.0200 (13) | 0.0127 (11) | 0.0203 (12) | 0.0014 (10) | 0.0084 (10) | 0.0013 (10) |
C5A | 0.0224 (15) | 0.0192 (14) | 0.0177 (14) | −0.0013 (12) | 0.0080 (12) | −0.0012 (12) |
C6 | 0.0234 (16) | 0.0146 (13) | 0.0263 (15) | −0.0015 (12) | 0.0056 (13) | −0.0039 (12) |
C7 | 0.0239 (16) | 0.0213 (15) | 0.0338 (17) | 0.0026 (14) | 0.0128 (14) | −0.0088 (14) |
C8 | 0.0307 (18) | 0.0271 (16) | 0.0294 (17) | −0.0038 (14) | 0.0164 (14) | −0.0084 (14) |
C9 | 0.0327 (17) | 0.0187 (15) | 0.0240 (16) | −0.0036 (13) | 0.0149 (13) | −0.0012 (12) |
C9A | 0.0217 (15) | 0.0169 (14) | 0.0197 (14) | 0.0005 (12) | 0.0065 (12) | −0.0040 (11) |
N10 | 0.0246 (13) | 0.0144 (11) | 0.0209 (12) | 0.0021 (10) | 0.0120 (11) | −0.0003 (10) |
C10A | 0.0200 (14) | 0.0148 (13) | 0.0192 (14) | 0.0004 (12) | 0.0066 (11) | 0.0023 (11) |
Geometric parameters (Å, º) top
N1—C10A | 1.343 (4) | C3—H3A | 0.9900 |
N1—C2 | 1.472 (4) | C3—H3B | 0.9900 |
N1—H1 | 0.8800 | C4—O4 | 1.203 (3) |
C2—C21 | 1.527 (4) | C4—N5 | 1.411 (4) |
C2—C3 | 1.531 (4) | N5—C10A | 1.411 (3) |
C2—H2 | 1.0000 | N5—C5A | 1.422 (4) |
C21—C26 | 1.385 (4) | C5A—C6 | 1.395 (4) |
C21—C22 | 1.412 (4) | C5A—C9A | 1.404 (4) |
C22—C23 | 1.396 (4) | C6—C7 | 1.394 (4) |
C22—H22 | 0.9500 | C6—H6 | 0.9500 |
C23—C24 | 1.393 (4) | C7—C8 | 1.395 (5) |
C23—H23 | 0.9500 | C7—H7 | 0.9500 |
C24—C25 | 1.389 (4) | C8—C9 | 1.404 (4) |
C24—Br24 | 1.914 (3) | C8—H8 | 0.9500 |
C25—C26 | 1.394 (4) | C9—C9A | 1.388 (4) |
C25—H25 | 0.9500 | C9—H9 | 0.9500 |
C26—H26 | 0.9500 | C9A—N10 | 1.417 (4) |
C3—C4 | 1.522 (4) | N10—C10A | 1.314 (4) |
| | | |
C10A—N1—C2 | 117.2 (2) | C2—C3—H3B | 108.8 |
C10A—N1—H1 | 121.4 | H3A—C3—H3B | 107.7 |
C2—N1—H1 | 121.4 | O4—C4—N5 | 120.7 (3) |
N1—C2—C21 | 109.8 (2) | O4—C4—C3 | 125.8 (3) |
N1—C2—C3 | 108.1 (2) | N5—C4—C3 | 113.4 (2) |
C21—C2—C3 | 112.7 (2) | C4—N5—C10A | 123.7 (2) |
N1—C2—H2 | 108.7 | C4—N5—C5A | 128.6 (2) |
C21—C2—H2 | 108.7 | C10A—N5—C5A | 106.3 (2) |
C3—C2—H2 | 108.7 | C6—C5A—C9A | 122.0 (3) |
C26—C21—C22 | 118.4 (3) | C6—C5A—N5 | 132.8 (3) |
C26—C21—C2 | 119.8 (3) | C9A—C5A—N5 | 105.0 (2) |
C22—C21—C2 | 121.7 (3) | C7—C6—C5A | 117.0 (3) |
C23—C22—C21 | 121.1 (3) | C7—C6—H6 | 121.5 |
C23—C22—H22 | 119.4 | C5A—C6—H6 | 121.5 |
C21—C22—H22 | 119.4 | C6—C7—C8 | 121.5 (3) |
C24—C23—C22 | 118.6 (3) | C6—C7—H7 | 119.2 |
C24—C23—H23 | 120.7 | C8—C7—H7 | 119.2 |
C22—C23—H23 | 120.7 | C7—C8—C9 | 120.9 (3) |
C25—C24—C23 | 121.2 (3) | C7—C8—H8 | 119.5 |
C25—C24—Br24 | 121.0 (2) | C9—C8—H8 | 119.5 |
C23—C24—Br24 | 117.8 (2) | C9A—C9—C8 | 118.0 (3) |
C24—C25—C26 | 119.3 (3) | C9A—C9—H9 | 121.0 |
C24—C25—H25 | 120.3 | C8—C9—H9 | 121.0 |
C26—C25—H25 | 120.3 | C9—C9A—C5A | 120.4 (3) |
C21—C26—C25 | 121.3 (3) | C9—C9A—N10 | 129.2 (3) |
C21—C26—H26 | 119.4 | C5A—C9A—N10 | 110.4 (3) |
C25—C26—H26 | 119.4 | C10A—N10—C9A | 105.9 (2) |
C4—C3—C2 | 113.8 (2) | N10—C10A—N1 | 128.0 (3) |
C4—C3—H3A | 108.8 | N10—C10A—N5 | 112.4 (2) |
C2—C3—H3A | 108.8 | N1—C10A—N5 | 119.6 (3) |
C4—C3—H3B | 108.8 | | |
| | | |
C10A—N1—C2—C21 | −174.8 (2) | C10A—N5—C5A—C6 | 173.0 (3) |
C10A—N1—C2—C3 | −51.5 (3) | C4—N5—C5A—C9A | 165.7 (3) |
N1—C2—C21—C26 | −131.3 (3) | C10A—N5—C5A—C9A | −1.2 (3) |
C3—C2—C21—C26 | 108.2 (3) | C9A—C5A—C6—C7 | −2.3 (4) |
N1—C2—C21—C22 | 46.5 (4) | N5—C5A—C6—C7 | −175.7 (3) |
C3—C2—C21—C22 | −74.0 (3) | C5A—C6—C7—C8 | −0.2 (4) |
C26—C21—C22—C23 | 0.9 (4) | C6—C7—C8—C9 | 1.1 (5) |
C2—C21—C22—C23 | −176.9 (3) | C7—C8—C9—C9A | 0.6 (5) |
C21—C22—C23—C24 | −0.7 (4) | C8—C9—C9A—C5A | −3.0 (4) |
C22—C23—C24—C25 | −0.1 (4) | C8—C9—C9A—N10 | 174.7 (3) |
C22—C23—C24—Br24 | 179.7 (2) | C6—C5A—C9A—C9 | 4.0 (4) |
C23—C24—C25—C26 | 0.6 (4) | N5—C5A—C9A—C9 | 179.0 (3) |
Br24—C24—C25—C26 | −179.2 (2) | C6—C5A—C9A—N10 | −174.1 (3) |
C22—C21—C26—C25 | −0.3 (4) | N5—C5A—C9A—N10 | 0.9 (3) |
C2—C21—C26—C25 | 177.5 (3) | C9—C9A—N10—C10A | −178.2 (3) |
C24—C25—C26—C21 | −0.4 (4) | C5A—C9A—N10—C10A | −0.2 (3) |
N1—C2—C3—C4 | 51.5 (3) | C9A—N10—C10A—N1 | 179.3 (3) |
C21—C2—C3—C4 | 173.0 (2) | C9A—N10—C10A—N5 | −0.6 (3) |
C2—C3—C4—O4 | 159.2 (3) | C2—N1—C10A—N10 | −159.2 (3) |
C2—C3—C4—N5 | −22.4 (4) | C2—N1—C10A—N5 | 20.6 (4) |
O4—C4—N5—C10A | 167.4 (3) | C4—N5—C10A—N10 | −166.6 (2) |
C3—C4—N5—C10A | −11.1 (4) | C5A—N5—C10A—N10 | 1.1 (3) |
O4—C4—N5—C5A | 2.5 (5) | C4—N5—C10A—N1 | 13.6 (4) |
C3—C4—N5—C5A | −175.9 (3) | C5A—N5—C10A—N1 | −178.7 (2) |
C4—N5—C5A—C6 | −20.1 (5) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···N10i | 0.88 | 2.30 | 2.943 (3) | 129 |
C9—H9···CgXi | 0.95 | 2.59 | 3.501 (3) | 158 |
Symmetry code: (i) −x+2, −y+1, −z. |
(Vb) 4-(4-Methylphenyl)-3,4-dihydropyrimido[1,2-
a]benzimidazol-2(1
H)-one
top
Crystal data top
C17H15N3O | Z = 2 |
Mr = 277.32 | F(000) = 292 |
Triclinic, P1 | Dx = 1.299 Mg m−3 |
Hall symbol: p-1 | Melting point: 506 K |
a = 8.1360 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.8647 (4) Å | Cell parameters from 3170 reflections |
c = 10.0975 (5) Å | θ = 3.0–27.5° |
α = 114.8796 (13)° | µ = 0.08 mm−1 |
β = 94.9156 (15)° | T = 120 K |
γ = 100.966 (3)° | Block, colourless |
V = 709.18 (5) Å3 | 0.1 × 0.1 × 0.1 mm |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3170 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 2247 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.056 |
ϕ scans, and ω scans with κ offsets | θmax = 27.5°, θmin = 3.0° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −10→10 |
Tmin = 0.992, Tmax = 0.992 | k = −12→12 |
10703 measured reflections | l = −13→13 |
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)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.120 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0664P)2 + 0.0023P] where P = (Fo2 + 2Fc2)/3 |
3170 reflections | (Δ/σ)max < 0.001 |
264 parameters | Δρmax = 0.21 e Å−3 |
52 restraints | Δρmin = −0.21 e Å−3 |
Crystal data top
C17H15N3O | γ = 100.966 (3)° |
Mr = 277.32 | V = 709.18 (5) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.1360 (3) Å | Mo Kα radiation |
b = 9.8647 (4) Å | µ = 0.08 mm−1 |
c = 10.0975 (5) Å | T = 120 K |
α = 114.8796 (13)° | 0.1 × 0.1 × 0.1 mm |
β = 94.9156 (15)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3170 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 2247 reflections with I > 2σ(I) |
Tmin = 0.992, Tmax = 0.992 | Rint = 0.056 |
10703 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.046 | 52 restraints |
wR(F2) = 0.120 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.21 e Å−3 |
3170 reflections | Δρmin = −0.21 e Å−3 |
264 parameters | |
Special details top
Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm
(Fox & Holmes, 1966) which effectively corrects for absorption effects.
High-redundancy data were used in the scaling program, hence the `multi-scan'
code-word was used. No transmission coefficients are available from the
program (only scale factors for each frame). The scale factors in the
experimental table are calculated from the SIZE command in the SHELXL97
input file. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
N1 | 0.91899 (12) | 0.67969 (12) | 0.51394 (12) | 0.0258 (3) | |
C2 | 0.90560 (16) | 0.82721 (16) | 0.55341 (15) | 0.0266 (3) | |
O2 | 1.01688 (11) | 0.93793 (11) | 0.64295 (11) | 0.0350 (3) | |
C3 | 0.75014 (16) | 0.84074 (15) | 0.47112 (16) | 0.0292 (3) | |
C4A | 0.58901 (17) | 0.71272 (16) | 0.43032 (16) | 0.0217 (4) | 0.907 (4) |
C41A | 0.4544 (3) | 0.71274 (19) | 0.3174 (3) | 0.0205 (4) | 0.907 (4) |
C42A | 0.4750 (2) | 0.6777 (2) | 0.1723 (3) | 0.0272 (5) | 0.907 (4) |
C43A | 0.3473 (4) | 0.6760 (2) | 0.0706 (2) | 0.0293 (6) | 0.907 (4) |
C44A | 0.1950 (4) | 0.7105 (4) | 0.1112 (3) | 0.0263 (7) | 0.907 (4) |
C45A | 0.1757 (3) | 0.7467 (3) | 0.2567 (3) | 0.0273 (6) | 0.907 (4) |
C46A | 0.3029 (3) | 0.7475 (2) | 0.35847 (19) | 0.0229 (5) | 0.907 (4) |
C47A | 0.0573 (3) | 0.7103 (2) | 0.0022 (3) | 0.0411 (5) | 0.907 (4) |
N5 | 0.63728 (12) | 0.56436 (12) | 0.37319 (12) | 0.0222 (3) | |
C5A | 0.53518 (16) | 0.41306 (15) | 0.29563 (14) | 0.0229 (3) | |
C6 | 0.36396 (16) | 0.35199 (16) | 0.23039 (15) | 0.0305 (4) | |
C7 | 0.30616 (18) | 0.19275 (16) | 0.16268 (17) | 0.0339 (4) | |
C8 | 0.41401 (17) | 0.09745 (16) | 0.15937 (15) | 0.0309 (4) | |
C9 | 0.58416 (17) | 0.15874 (16) | 0.22647 (14) | 0.0263 (3) | |
C9A | 0.64417 (15) | 0.31836 (15) | 0.29690 (14) | 0.0217 (3) | |
N10 | 0.80576 (13) | 0.40885 (13) | 0.37738 (12) | 0.0251 (3) | |
C10A | 0.79250 (15) | 0.55081 (15) | 0.42150 (14) | 0.0217 (3) | |
C4B | 0.6609 (15) | 0.7020 (14) | 0.3331 (15) | 0.025 (4) | 0.093 (4) |
C41B | 0.492 (2) | 0.710 (2) | 0.259 (3) | 0.019 (4) | 0.093 (4) |
C42B | 0.377 (4) | 0.735 (2) | 0.346 (2) | 0.017 (4) | 0.093 (4) |
C43B | 0.215 (3) | 0.742 (3) | 0.292 (3) | 0.020 (4) | 0.093 (4) |
C44B | 0.172 (3) | 0.712 (4) | 0.149 (4) | 0.013 (4) | 0.093 (4) |
C45B | 0.280 (4) | 0.680 (3) | 0.070 (3) | 0.019 (4) | 0.093 (4) |
C46B | 0.442 (3) | 0.684 (2) | 0.113 (3) | 0.022 (4) | 0.093 (4) |
C47B | −0.001 (3) | 0.714 (3) | 0.066 (3) | 0.058 (7) | 0.093 (4) |
H1 | 1.0140 | 0.6666 | 0.5498 | 0.031* | |
H3A | 0.7780 | 0.8435 | 0.3786 | 0.035* | |
H3B | 0.7254 | 0.9406 | 0.5331 | 0.035* | |
H4A | 0.5416 | 0.7282 | 0.5223 | 0.026* | 0.907 (4) |
H42A | 0.5779 | 0.6547 | 0.1422 | 0.033* | 0.907 (4) |
H43A | 0.3638 | 0.6509 | −0.0282 | 0.035* | 0.907 (4) |
H45A | 0.0736 | 0.7714 | 0.2873 | 0.033* | 0.907 (4) |
H46A | 0.2862 | 0.7720 | 0.4571 | 0.028* | 0.907 (4) |
H47A | 0.1064 | 0.7223 | −0.0787 | 0.062* | 0.4535 (18) |
H47B | 0.0056 | 0.7960 | 0.0526 | 0.062* | 0.4535 (18) |
H47C | −0.0300 | 0.6125 | −0.0384 | 0.062* | 0.4535 (18) |
H47D | −0.0517 | 0.6982 | 0.0357 | 0.062* | 0.4535 (18) |
H47E | 0.0490 | 0.6245 | −0.0956 | 0.062* | 0.4535 (18) |
H47F | 0.0847 | 0.8080 | −0.0046 | 0.062* | 0.4535 (18) |
H6 | 0.2901 | 0.4163 | 0.2321 | 0.037* | |
H7 | 0.1896 | 0.1470 | 0.1171 | 0.041* | |
H8 | 0.3699 | −0.0114 | 0.1102 | 0.037* | |
H9 | 0.6574 | 0.0938 | 0.2244 | 0.032* | |
H4B | 0.7392 | 0.6852 | 0.2597 | 0.030* | 0.093 (4) |
H42B | 0.4037 | 0.7477 | 0.4448 | 0.021* | 0.093 (4) |
H43B | 0.1355 | 0.7676 | 0.3571 | 0.024* | 0.093 (4) |
H45B | 0.2448 | 0.6496 | −0.0327 | 0.023* | 0.093 (4) |
H46B | 0.5199 | 0.6689 | 0.0467 | 0.026* | 0.093 (4) |
H47G | −0.0869 | 0.6187 | 0.0421 | 0.087* | 0.0465 (18) |
H47H | 0.0177 | 0.7210 | −0.0255 | 0.087* | 0.0465 (18) |
H47I | −0.0397 | 0.8030 | 0.1309 | 0.087* | 0.0465 (18) |
H47J | 0.0143 | 0.8098 | 0.0562 | 0.087* | 0.0465 (18) |
H47K | −0.0903 | 0.7074 | 0.1238 | 0.087* | 0.0465 (18) |
H47L | −0.0329 | 0.6255 | −0.0326 | 0.087* | 0.0465 (18) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0172 (6) | 0.0244 (6) | 0.0357 (7) | 0.0054 (5) | 0.0014 (5) | 0.0140 (5) |
C2 | 0.0216 (7) | 0.0258 (8) | 0.0345 (8) | 0.0060 (6) | 0.0059 (6) | 0.0151 (7) |
O2 | 0.0270 (6) | 0.0259 (6) | 0.0458 (7) | 0.0012 (4) | −0.0021 (5) | 0.0140 (5) |
C3 | 0.0257 (7) | 0.0226 (7) | 0.0391 (9) | 0.0068 (6) | 0.0015 (6) | 0.0141 (7) |
C4A | 0.0221 (8) | 0.0201 (8) | 0.0248 (9) | 0.0073 (6) | 0.0050 (6) | 0.0107 (6) |
C41A | 0.0221 (10) | 0.0175 (8) | 0.0245 (10) | 0.0078 (7) | 0.0057 (8) | 0.0105 (8) |
C42A | 0.0298 (10) | 0.0318 (10) | 0.0274 (13) | 0.0160 (8) | 0.0094 (9) | 0.0160 (10) |
C43A | 0.0322 (15) | 0.0361 (11) | 0.0264 (10) | 0.0148 (11) | 0.0094 (11) | 0.0169 (8) |
C44A | 0.0315 (14) | 0.0232 (10) | 0.0266 (16) | 0.0081 (9) | 0.0027 (11) | 0.0131 (12) |
C45A | 0.0187 (11) | 0.0329 (10) | 0.0310 (16) | 0.0087 (8) | 0.0020 (8) | 0.0145 (10) |
C46A | 0.0207 (11) | 0.0252 (9) | 0.0232 (9) | 0.0072 (8) | 0.0042 (8) | 0.0104 (7) |
C47A | 0.0374 (12) | 0.0423 (11) | 0.0421 (13) | 0.0085 (9) | −0.0089 (9) | 0.0210 (10) |
N5 | 0.0191 (6) | 0.0210 (6) | 0.0285 (6) | 0.0069 (4) | 0.0021 (4) | 0.0125 (5) |
C5A | 0.0248 (7) | 0.0213 (7) | 0.0245 (7) | 0.0069 (5) | 0.0044 (5) | 0.0116 (6) |
C6 | 0.0255 (8) | 0.0278 (8) | 0.0366 (8) | 0.0066 (6) | −0.0026 (6) | 0.0144 (7) |
C7 | 0.0285 (8) | 0.0280 (8) | 0.0385 (9) | 0.0025 (6) | −0.0057 (6) | 0.0128 (7) |
C8 | 0.0371 (8) | 0.0227 (7) | 0.0282 (8) | 0.0044 (6) | 0.0015 (6) | 0.0090 (6) |
C9 | 0.0322 (8) | 0.0245 (7) | 0.0245 (7) | 0.0117 (6) | 0.0056 (6) | 0.0112 (6) |
C9A | 0.0239 (7) | 0.0238 (7) | 0.0206 (7) | 0.0083 (5) | 0.0047 (5) | 0.0117 (6) |
N10 | 0.0224 (6) | 0.0241 (6) | 0.0286 (6) | 0.0078 (5) | 0.0026 (5) | 0.0113 (5) |
C10A | 0.0191 (7) | 0.0247 (7) | 0.0251 (7) | 0.0074 (5) | 0.0058 (5) | 0.0134 (6) |
C4B | 0.022 (8) | 0.023 (8) | 0.040 (10) | 0.006 (6) | 0.013 (6) | 0.022 (7) |
C41B | 0.016 (5) | 0.022 (6) | 0.019 (5) | 0.006 (4) | 0.003 (3) | 0.010 (4) |
C42B | 0.018 (5) | 0.023 (6) | 0.016 (5) | 0.007 (4) | 0.002 (3) | 0.012 (4) |
C43B | 0.018 (5) | 0.029 (6) | 0.016 (5) | 0.010 (4) | 0.005 (4) | 0.009 (4) |
C44B | 0.014 (5) | 0.012 (6) | 0.014 (5) | 0.006 (4) | −0.001 (4) | 0.006 (4) |
C45B | 0.020 (5) | 0.023 (6) | 0.016 (5) | 0.006 (5) | 0.003 (3) | 0.009 (4) |
C46B | 0.020 (5) | 0.029 (6) | 0.018 (5) | 0.007 (4) | 0.005 (4) | 0.009 (4) |
C47B | 0.036 (12) | 0.076 (16) | 0.051 (15) | 0.022 (10) | 0.021 (10) | 0.013 (12) |
Geometric parameters (Å, º) top
N1—C2 | 1.3668 (17) | C5A—C6 | 1.3882 (18) |
N1—C10A | 1.3732 (16) | C5A—C9A | 1.4080 (18) |
N1—H1 | 0.8800 | C6—C7 | 1.384 (2) |
C2—O2 | 1.2176 (16) | C6—H6 | 0.9500 |
C2—C3 | 1.5118 (17) | C7—C8 | 1.395 (2) |
C3—C4B | 1.478 (13) | C7—H7 | 0.9500 |
C3—C4A | 1.5242 (18) | C8—C9 | 1.3846 (19) |
C3—H3A | 0.9900 | C8—H8 | 0.9500 |
C3—H3B | 0.9900 | C9—C9A | 1.3889 (19) |
C4A—N5 | 1.4752 (17) | C9—H9 | 0.9500 |
C4A—C41A | 1.512 (2) | C9A—N10 | 1.3948 (16) |
C4A—H4A | 1.0000 | N10—C10A | 1.3084 (17) |
C41A—C42A | 1.390 (3) | C4B—C41B | 1.541 (18) |
C41A—C46A | 1.391 (3) | C4B—H4B | 1.0000 |
C42A—C43A | 1.389 (3) | C41B—C42B | 1.32 (3) |
C42A—H42A | 0.9500 | C41B—C46B | 1.39 (3) |
C43A—C44A | 1.396 (3) | C42B—C43B | 1.41 (3) |
C43A—H43A | 0.9500 | C42B—H42B | 0.9500 |
C44A—C45A | 1.389 (3) | C43B—C44B | 1.35 (3) |
C44A—C47A | 1.501 (3) | C43B—H43B | 0.9500 |
C45A—C46A | 1.391 (2) | C44B—C45B | 1.23 (3) |
C45A—H45A | 0.9500 | C44B—C47B | 1.58 (4) |
C46A—H46A | 0.9500 | C45B—C46B | 1.34 (3) |
C47A—H47A | 0.9800 | C45B—H45B | 0.9500 |
C47A—H47B | 0.9800 | C46B—H46B | 0.9500 |
C47A—H47C | 0.9800 | C47B—H47G | 0.9800 |
C47A—H47D | 0.9800 | C47B—H47H | 0.9800 |
C47A—H47E | 0.9800 | C47B—H47I | 0.9800 |
C47A—H47F | 0.9800 | C47B—H47J | 0.9800 |
N5—C10A | 1.3653 (15) | C47B—H47K | 0.9800 |
N5—C5A | 1.4016 (17) | C47B—H47L | 0.9800 |
N5—C4B | 1.555 (12) | | |
| | | |
C2—N1—C10A | 123.66 (11) | C7—C8—H8 | 119.4 |
C2—N1—H1 | 118.2 | C8—C9—C9A | 117.79 (13) |
C10A—N1—H1 | 118.2 | C8—C9—H9 | 121.1 |
O2—C2—N1 | 121.28 (12) | C9A—C9—H9 | 121.1 |
O2—C2—C3 | 123.55 (12) | C9—C9A—N10 | 129.38 (12) |
N1—C2—C3 | 115.07 (11) | C9—C9A—C5A | 120.45 (12) |
C4B—C3—C2 | 116.0 (5) | N10—C9A—C5A | 110.15 (11) |
C4B—C3—C4A | 45.5 (5) | C10A—N10—C9A | 104.27 (10) |
C2—C3—C4A | 115.86 (11) | N10—C10A—N5 | 114.87 (11) |
C4B—C3—H3A | 65.4 | N10—C10A—N1 | 124.52 (11) |
C2—C3—H3A | 108.3 | N5—C10A—N1 | 120.56 (11) |
C4A—C3—H3A | 108.3 | C3—C4B—C41B | 115.7 (12) |
C4B—C3—H3B | 135.2 | C3—C4B—N5 | 106.1 (8) |
C2—C3—H3B | 108.3 | C41B—C4B—N5 | 112.0 (11) |
C4A—C3—H3B | 108.3 | C3—C4B—H4B | 107.6 |
H3A—C3—H3B | 107.4 | C41B—C4B—H4B | 107.6 |
N5—C4A—C41A | 110.90 (12) | N5—C4B—H4B | 107.6 |
N5—C4A—C3 | 107.85 (10) | C42B—C41B—C46B | 117.3 (16) |
C41A—C4A—C3 | 112.18 (13) | C42B—C41B—C4B | 114 (2) |
N5—C4A—H4A | 108.6 | C46B—C41B—C4B | 129 (2) |
C41A—C4A—H4A | 108.6 | C41B—C42B—C43B | 120.2 (17) |
C3—C4A—H4A | 108.6 | C41B—C42B—H42B | 119.9 |
C42A—C41A—C46A | 118.19 (15) | C43B—C42B—H42B | 119.9 |
C42A—C41A—C4A | 122.4 (2) | C44B—C43B—C42B | 120 (2) |
C46A—C41A—C4A | 119.4 (2) | C44B—C43B—H43B | 120.1 |
C43A—C42A—C41A | 120.92 (17) | C42B—C43B—H43B | 120.1 |
C43A—C42A—H42A | 119.5 | C45B—C44B—C43B | 118 (3) |
C41A—C42A—H42A | 119.5 | C45B—C44B—C47B | 114 (3) |
C42A—C43A—C44A | 121.10 (19) | C43B—C44B—C47B | 128 (3) |
C42A—C43A—H43A | 119.4 | C44B—C45B—C46B | 127 (2) |
C44A—C43A—H43A | 119.4 | C44B—C45B—H45B | 116.5 |
C45A—C44A—C43A | 117.7 (2) | C46B—C45B—H45B | 116.5 |
C45A—C44A—C47A | 121.0 (3) | C45B—C46B—C41B | 118 (2) |
C43A—C44A—C47A | 121.3 (2) | C45B—C46B—H46B | 121.2 |
C44A—C45A—C46A | 121.3 (2) | C41B—C46B—H46B | 121.2 |
C44A—C45A—H45A | 119.4 | C44B—C47B—H47G | 109.5 |
C46A—C45A—H45A | 119.4 | C44B—C47B—H47H | 109.5 |
C45A—C46A—C41A | 120.78 (17) | H47G—C47B—H47H | 109.5 |
C45A—C46A—H46A | 119.6 | C44B—C47B—H47I | 109.5 |
C41A—C46A—H46A | 119.6 | H47G—C47B—H47I | 109.5 |
C10A—N5—C5A | 105.53 (10) | H47H—C47B—H47I | 109.5 |
C10A—N5—C4A | 122.62 (10) | C44B—C47B—H47J | 109.5 |
C5A—N5—C4A | 130.07 (10) | H47G—C47B—H47J | 141.1 |
C10A—N5—C4B | 109.9 (5) | H47H—C47B—H47J | 56.3 |
C5A—N5—C4B | 130.7 (5) | H47I—C47B—H47J | 56.3 |
C4A—N5—C4B | 45.0 (5) | C44B—C47B—H47K | 109.5 |
C6—C5A—N5 | 133.08 (12) | H47G—C47B—H47K | 56.3 |
C6—C5A—C9A | 121.84 (12) | H47H—C47B—H47K | 141.1 |
N5—C5A—C9A | 105.05 (10) | H47I—C47B—H47K | 56.3 |
C7—C6—C5A | 116.74 (13) | H47J—C47B—H47K | 109.5 |
C7—C6—H6 | 121.6 | C44B—C47B—H47L | 109.5 |
C5A—C6—H6 | 121.6 | H47G—C47B—H47L | 56.3 |
C6—C7—C8 | 121.96 (13) | H47H—C47B—H47L | 56.3 |
C6—C7—H7 | 119.0 | H47I—C47B—H47L | 141.1 |
C8—C7—H7 | 119.0 | H47J—C47B—H47L | 109.5 |
C9—C8—C7 | 121.16 (13) | H47K—C47B—H47L | 109.5 |
C9—C8—H8 | 119.4 | | |
| | | |
C10A—N1—C2—O2 | 175.39 (12) | C8—C9—C9A—C5A | −1.7 (2) |
C10A—N1—C2—C3 | −8.25 (19) | C6—C5A—C9A—C9 | 2.8 (2) |
O2—C2—C3—C4B | 159.6 (6) | N5—C5A—C9A—C9 | −178.90 (11) |
N1—C2—C3—C4B | −16.6 (6) | C6—C5A—C9A—N10 | −176.15 (12) |
O2—C2—C3—C4A | −149.42 (14) | N5—C5A—C9A—N10 | 2.18 (14) |
N1—C2—C3—C4A | 34.31 (17) | C9—C9A—N10—C10A | −178.84 (14) |
C4B—C3—C4A—N5 | 58.4 (7) | C5A—C9A—N10—C10A | −0.05 (14) |
C2—C3—C4A—N5 | −43.44 (16) | C9A—N10—C10A—N5 | −2.30 (15) |
C4B—C3—C4A—C41A | −64.0 (7) | C9A—N10—C10A—N1 | 175.22 (12) |
C2—C3—C4A—C41A | −165.86 (15) | C5A—N5—C10A—N10 | 3.71 (15) |
N5—C4A—C41A—C42A | −53.9 (2) | C4A—N5—C10A—N10 | 169.91 (12) |
C3—C4A—C41A—C42A | 66.80 (19) | C4B—N5—C10A—N10 | −141.5 (5) |
N5—C4A—C41A—C46A | 125.51 (16) | C5A—N5—C10A—N1 | −173.92 (11) |
C3—C4A—C41A—C46A | −113.82 (17) | C4A—N5—C10A—N1 | −7.72 (19) |
C46A—C41A—C42A—C43A | −0.6 (3) | C4B—N5—C10A—N1 | 40.9 (6) |
C4A—C41A—C42A—C43A | 178.77 (16) | C2—N1—C10A—N10 | 176.90 (13) |
C41A—C42A—C43A—C44A | 0.5 (3) | C2—N1—C10A—N5 | −5.7 (2) |
C42A—C43A—C44A—C45A | 0.1 (4) | C2—C3—C4B—C41B | 173.3 (12) |
C42A—C43A—C44A—C47A | 179.4 (2) | C4A—C3—C4B—C41B | 71.7 (13) |
C43A—C44A—C45A—C46A | −0.5 (4) | C2—C3—C4B—N5 | 48.4 (8) |
C47A—C44A—C45A—C46A | −179.8 (2) | C4A—C3—C4B—N5 | −53.2 (5) |
C44A—C45A—C46A—C41A | 0.4 (3) | C10A—N5—C4B—C3 | −60.1 (8) |
C42A—C41A—C46A—C45A | 0.2 (3) | C5A—N5—C4B—C3 | 166.5 (3) |
C4A—C41A—C46A—C45A | −179.24 (16) | C4A—N5—C4B—C3 | 56.6 (6) |
C41A—C4A—N5—C10A | 154.46 (15) | C10A—N5—C4B—C41B | 172.7 (12) |
C3—C4A—N5—C10A | 31.26 (17) | C5A—N5—C4B—C41B | 39.3 (15) |
C41A—C4A—N5—C5A | −43.0 (2) | C4A—N5—C4B—C41B | −70.6 (13) |
C3—C4A—N5—C5A | −166.21 (12) | C3—C4B—C41B—C42B | −59 (2) |
C41A—C4A—N5—C4B | 68.4 (7) | N5—C4B—C41B—C42B | 63.2 (19) |
C3—C4A—N5—C4B | −54.8 (7) | C3—C4B—C41B—C46B | 126.4 (19) |
C10A—N5—C5A—C6 | 174.71 (15) | N5—C4B—C41B—C46B | −112 (2) |
C4A—N5—C5A—C6 | 9.9 (2) | C46B—C41B—C42B—C43B | −3 (3) |
C4B—N5—C5A—C6 | −50.4 (7) | C4B—C41B—C42B—C43B | −178.8 (18) |
C10A—N5—C5A—C9A | −3.35 (13) | C41B—C42B—C43B—C44B | 5 (4) |
C4A—N5—C5A—C9A | −168.14 (12) | C42B—C43B—C44B—C45B | −1 (4) |
C4B—N5—C5A—C9A | 131.5 (6) | C42B—C43B—C44B—C47B | −180 (2) |
N5—C5A—C6—C7 | −179.56 (14) | C43B—C44B—C45B—C46B | −6 (5) |
C9A—C5A—C6—C7 | −1.8 (2) | C47B—C44B—C45B—C46B | 173 (2) |
C5A—C6—C7—C8 | −0.2 (2) | C44B—C45B—C46B—C41B | 7 (4) |
C6—C7—C8—C9 | 1.1 (2) | C42B—C41B—C46B—C45B | −2 (3) |
C7—C8—C9—C9A | −0.2 (2) | C4B—C41B—C46B—C45B | 172.5 (19) |
C8—C9—C9A—N10 | 176.98 (12) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···N10i | 0.88 | 1.98 | 2.8481 (16) | 167 |
C3—H3A···O2ii | 0.99 | 2.56 | 3.2561 (19) | 127 |
C4A—H4A···CgYiii | 1.00 | 2.43 | 3.419 (16) | 159 |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+2, −y+2, −z+1; (iii) −x+1, −y+1, −z+1. |
Experimental details
| (IVa) | (Vb) |
Crystal data |
Chemical formula | C16H12BrN3O | C17H15N3O |
Mr | 342.20 | 277.32 |
Crystal system, space group | Monoclinic, P21/c | Triclinic, P1 |
Temperature (K) | 120 | 120 |
a, b, c (Å) | 6.8807 (2), 16.2254 (6), 13.3379 (5) | 8.1360 (3), 9.8647 (4), 10.0975 (5) |
α, β, γ (°) | 90, 111.280 (2), 90 | 114.8796 (13), 94.9156 (15), 100.966 (3) |
V (Å3) | 1387.54 (8) | 709.18 (5) |
Z | 4 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 2.96 | 0.08 |
Crystal size (mm) | 0.20 × 0.06 × 0.02 | 0.1 × 0.1 × 0.1 |
|
Data collection |
Diffractometer | Nonius KappaCCD area-detector diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.589, 0.943 | 0.992, 0.992 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8697, 3046, 2401 | 10703, 3170, 2247 |
Rint | 0.078 | 0.056 |
(sin θ/λ)max (Å−1) | 0.648 | 0.650 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.114, 1.01 | 0.046, 0.120, 1.05 |
No. of reflections | 3046 | 3170 |
No. of parameters | 190 | 264 |
No. of restraints | 0 | 52 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.71, −1.55 | 0.21, −0.21 |
Hydrogen-bond geometry (Å, º) for (IVa) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···N10i | 0.88 | 2.30 | 2.943 (3) | 129 |
C9—H9···CgXi | 0.95 | 2.59 | 3.501 (3) | 158 |
Symmetry code: (i) −x+2, −y+1, −z. |
Hydrogen-bond geometry (Å, º) for (Vb) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···N10i | 0.88 | 1.98 | 2.8481 (16) | 167 |
C3—H3A···O2ii | 0.99 | 2.56 | 3.2561 (19) | 127 |
C4A—H4A···CgYiii | 1.00 | 2.43 | 3.419 (16) | 159 |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+2, −y+2, −z+1; (iii) −x+1, −y+1, −z+1. |
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Benzimidazoles are associated with antiparasitic (Loewe et al., 1978), central nervous system depressant and anti-inflammatory (Yale & Bristol, 1977; Denzel & Hoehn, 1978a,b) and other pharmacological activities (Berg & Parnell, 1961; Mendzneritskaya et al., 1978; Paget et al., 1969, 1980). Hence, it may be expected that pyrimidobenzimidazoles such as the title compounds, (I) and (II), might display potent biological activity.
In previous research (Quiroga et al., 1999 and references therein) we have shown that the reaction between heterocyclic amines and benzylidene derivatives of compounds with an active methylene group, such Meldrum's acid, dimedone, malonodinitrile or ethyl cyanoacetate, is a good synthetic procedure to produce fused pyridinic and pyrimidinic systems. Here, we describe two regioisomer compounds obtained from the reaction of 2-aminobenzimidazole, (1), the benzaldehydes (2a) and (2 b) and Meldrum's acid, (3). The isomerism in the reaction is due to the two non-equivalent nucleophilic centres in (1), the NH2 group and the endo N. The formation of both products was observed in the two reactions. Related processes with Meldrum's acids are well known (McNab, 1978; Brown et al., 1974). Herein we describe the X-ray crystal structures for the crystalline derivatives with R = Br, (4a), hereinafter (I), and R = CH3, (5 b), hereinafter (II). \sch
Compound (I) (Fig. 1) crystallizes in the monoclinic spacegroup P21/c and (II) (Fig. 2) in the triclinic spacegroup P1. In (II), there is disorder involving the envelope dihydropyrimido part of the molecule, such that the C atom of the envelope lies below and above the mean plane of the other five ring atoms, for the major and minor components, respectively, which are in the ratio 0.9:0.1. This disorder consists of two non-interchangeable conformers, each with an equatorial tolyl group and an axial methine H atom. Thus, two enantiomers are present, since a straightforward `flip' of the envelope would give an axial tolyl and an equatorial H. A view of the two components of the disorder is shown in Fig. 3.
In both compounds, an R22(8) centrosymmetric base-paired dimer (Bernstein et al., 1995) is formed, via the N1—H1···N10(2 - x, 1 - y, -z) hydrogen bond in (I) (Fig. 4) and the corresponding N1—H1···N10(2 - x, 1 - y, 1 - z) hydrogen bond in (II). There is a short Br24.. O4(1 - x, 1/2 + y, 1/2 - z) contact of 3.117 (2) Å in (I). In the case of (II), there is a weak C3—H3A···O2(2 - x, 1 - y, 1 - z)hydrogen bond, with a C···O distance of 3.2561 (19) Å and a C3—H3A···O2 angle of 127 Å. This latter interaction forms an R22(8) ring. These two ring structures link the molecules into a continuous ribbon which runs parallel to the b axis. Alternatively, this ribbon can be regarded as being formed by two antiparallel C22(10) centrosymmetrically related chains (Fig. 5).
The supramolecular structures of the two compounds differ in other respects as well. Both compounds contain different C—H···π(arene) interactions. In (I), there is a C9—H9···CgX(2 - x, 1 - y, -z) contact of 2.59 Å, where CgX is the centroid of ring X, and X is the ring C21—C26. The perpendicular distance C9···CgX is 2.58 Å and the angle at H9 is 158°. This interaction reinforces the strong N—H···O bond described above, since it involves the same two molecules which are thus linked head-to-tail. This interaction can be seen in Figs. 4 and 6. Thus in (I), the main supramolecular structure is the dimer.
In (II), there is a C4A—H4A···CgY(1 - x, 1 - y, 1 - z) contact of 2.47 Å (Y is the ring C5a—C9a). The perpendicular distance C4A···CgY (Please check C4A is correct - C9 given in original CIF) is 2.43 Å and the angle at H4A is 159°. This H···π distance is rather short at ca 2.40 Å, if C—H is given the neutron value of 1.083 Å. This means that it lies within 0.10–0.15 Å of the values found in some alkynyltetraborate structures (Lindeman et al., 1998). Fig. 7 shows that the molecules are linked head-to-tail by this interaction. The minor component of (II) is not involved in any such interaction. Details of all hydrogen bonding are given in Tables 1 and 2.
Only one similar compound which includes H atoms in the analysis was found in the Cambridge Structural Database (CSD, Release?; Allen & Kennard, 1993), namely 2,2-dimethyl-1,2,3,4-tetrahydrobenzimidazo[3,2-a]pyrimid-4-one (VOBLAZ; Bird et al., 1991). In this structure, an identical dimer to that found for (I) and (II) is formed, with an N···N distance of 3.037 (3) Å and an angle at H of 175°. There are C—H···O contacts, but these are too long to be classed as weak hydrogen bonds. In addition, there is a C—H···π(arene) contact involving a methyl H atom of 2.79 Å (perpendicular distance 2.78 Å), with an angle at H of 176°. One noticeable feature of this compound which differs markedly from (I) and (II) is the difference in the angles at the H atoms, which suggests that the interplay between the C—H···π hydrogen bonds, which are very much shorter in (I) and (II) than in VOBLAZ, may have sufficient strength to distort the N—H···N hydrogen bonds in (I) and (II).