4-(4-Bromo­phenyl)-3,7,7-tri­methyl-4,7,8,9-tetra­hydro-2H-pyrazolo­[3,4-b]quinolin-5(6H)-one

Cannon, D.; Quesada, A.; Quiroga, J.; Mejía, D.; Insuasty, B.; Abonia, R.; Cobo, J.; Nogueras, M.; Sánchez, A.; Low, J.N.

doi:10.1107/S1600536801001453

4-(4-Bromophenyl)-3,7,7-trimethyl-4,7,8,9-tetrahydro-2H-pyrazolo[3,4-b]quinolin-5(6H)-one

D. Cannon, A. Quesada, J. Quiroga, D. Mejía, B. Insuasty, R. Abonia, J. Cobo, M. Nogueras, A. Sánchez and J. N. Low

The title compound, C₁₉H₂₀BrN₃O, has a supramolecular structure of hydrogen bonding comprising N—H

O bonds which form a series of anti-parallel C(8) chains linked together by N—H

N R²₂(8) base-paired motifs which together form corrugated sheets containing R⁶₆(34) rings. This is one of a series of four substituted 3,7,7-trimethyl-4,7,8,9-tetrahydro-2H-pyrazolo[3,4-b]quinolin-5(6H)-one compounds which all have identical supramolecular structures.

Read article Similar articles

Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801001453/na6036sup1.cif Contains datablocks global, 1
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536801001453/na6036Isup2.hkl Contains datablock I

CCDC reference: 159750

checkCIF report

Key indicators

Single-crystal X-ray study
T = 150 K
Mean (C-C) = 0.004 Å
R factor = 0.035
wR factor = 0.096
Data-to-parameter ratio = 13.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

Comment top

Pyrazolo[3,4-b]quinolines are of interest as possible antiviral agents (Crenshaw et al., 1976, 1978; Smirnoff and Crenshaw, 1977). Some of their derivatives exhibit parasiticidic properties (Bristol-Meyers Co, 1973), and have been studied as potential anti-malarial agents (Stein et al., 1970). Some pyrazolo([3,4-b]quinolines have shown bactericidal activity (Farghaly et al., 1989), have also been used as vasodilators (Bell & Ackerman, 1990) and evaluated for enzymatic inhibitory activity (Gatta et al., 1991).

In previous reports, (Quiroga, Hormaza et al., 1998; Quiroga, Insuasty et al., 1998), we have reported an efficient and versatile synthesis of novel 4,7,8,9-tetrahydro-pyrimido-and 4,7,8,9-tetrahydropyrazolo[3,4-b] quinolin-5-ones from suitable pyrimidine and pyrazole amines to which dimedone and substituted benzaldehyde afford the ring annelation to quinoline.

Selected bond lengths and angles are given in Table 1 while a view of the molecule is given in Figure 1. The hydrogen bonding pattern comprises anti-parallel C(8), [N2–H2···O51ⁱ], chains linked together by R²₂(8), [N9–H9···N1ⁱⁱ], base-paired motifs (Bernstein et al., 1995). This combination forms a corrugated sheet which contains R⁶₆(34) rings. This structure is shown in Fig. 2. The details of the hydrogen bonds are given in Table 2.

Examination of the structure with PLATON (Spek, 2000) showed that there were no solvent accessible voids in the crystal lattice.

Experimental top

A solution of 5-aminopyrazole (1 mmol), dimedone (1 mmol) and 4-bromobenzaldehyde (1 mmol) in 15 ml of absolute ethanol were heated to reflux for 20–50 min (thin-layer chromatography control). The reaction mixture was cooled and the solid corresponding to the title compound was filtered off, washed with ethanol, dried and recrystallized from ethanol to afford crystals suitable for diffraction analysis (70% yield, m.p. 587–588 K).

Computing details top

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, 2000); software used to prepare material for publication: SHELXL97 and WORDPERFECT macro PRPKAPPA (Ferguson, 1999).

Figures top

	Fig. 1. A view of the molecule with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. View of the hydrogen-bonded sheets lying parallel to [010] showing the C(8) chains, the R²₂(8) rings and the R⁸₈(34) rings. Atom O51ⁱ is at (0.5 - x, -0.5 + y, 1.5 - z) and atom N1ⁱⁱ is at (-x, 1 - y, 1 - z).

4-(4-bromophenyl)-3,7,7-trimethyl-4,7,8,9-tetrahydro-2H-pyrazolo[3,4-b] quinolin-5(6H)-one top

Crystal data top

C₁₉H₂₀BrN₃O	D_x = 1.466 Mg m⁻³
M_r = 386.29	Melting point: 587 K
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 8.6673 (2) Å	Cell parameters from 4653 reflections
b = 14.6092 (3) Å	θ = 1.0–30.5°
c = 14.4783 (5) Å	µ = 2.36 mm⁻¹
β = 107.287 (1)°	T = 150 K
V = 1750.46 (8) Å³	Block, colourless
Z = 4	0.22 × 0.20 × 0.13 mm
F(000) = 792

Data collection top

KappaCCD diffractometer	2971 independent reflections
Radiation source: fine-focus sealed X-ray tube	2457 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.041
ϕ and ω scans with κ offsets	θ_max = 25.0°, θ_min = 2.0°
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	h = −10→9
T_min = 0.620, T_max = 0.757	k = −15→17
10467 measured reflections	l = −14→17

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.096	H-atom parameters constrained
S = 0.98	w = 1/[σ²(F_o²) + (0.0565P)² + 1.064P] where P = (F_o² + 2F_c²)/3
2971 reflections	(Δ/σ)_max < 0.001
220 parameters	Δρ_max = 0.34 e Å⁻³
0 restraints	Δρ_min = −0.69 e Å⁻³

Crystal data top

C₁₉H₂₀BrN₃O	V = 1750.46 (8) Å³
M_r = 386.29	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 8.6673 (2) Å	µ = 2.36 mm⁻¹
b = 14.6092 (3) Å	T = 150 K
c = 14.4783 (5) Å	0.22 × 0.20 × 0.13 mm
β = 107.287 (1)°

Data collection top

KappaCCD diffractometer	2971 independent reflections
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	2457 reflections with I > 2σ(I)
T_min = 0.620, T_max = 0.757	R_int = 0.041
10467 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.096	H-atom parameters constrained
S = 0.98	Δρ_max = 0.34 e Å⁻³
2971 reflections	Δρ_min = −0.69 e Å⁻³
220 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	U_iso*/U_eq
Br1	−0.09022 (4)	1.01949 (2)	0.84992 (2)	0.04207 (15)
N1	0.0258 (3)	0.50866 (14)	0.62544 (15)	0.0199 (5)
N2	0.0657 (3)	0.49693 (14)	0.72350 (15)	0.0195 (5)
C3	0.1663 (3)	0.56229 (17)	0.77329 (17)	0.0169 (5)
C31	0.2301 (3)	0.55976 (19)	0.88096 (18)	0.0239 (6)
C3A	0.1942 (3)	0.62174 (17)	0.70591 (18)	0.0174 (5)
C4	0.2828 (3)	0.71108 (16)	0.71244 (17)	0.0162 (5)
C41	0.1923 (3)	0.78752 (16)	0.74617 (17)	0.0173 (5)
C42	0.0503 (3)	0.82395 (18)	0.68373 (18)	0.0236 (6)
C43	−0.0344 (4)	0.89235 (19)	0.7149 (2)	0.0282 (6)
C44	0.0238 (3)	0.92447 (18)	0.8085 (2)	0.0270 (6)
C45	0.1620 (3)	0.88979 (19)	0.8717 (2)	0.0265 (6)
C46	0.2455 (3)	0.82105 (18)	0.84023 (18)	0.0219 (6)
C4A	0.3055 (3)	0.73065 (16)	0.61405 (17)	0.0152 (5)
C5	0.4245 (3)	0.79835 (16)	0.61028 (18)	0.0164 (5)
O51	0.5056 (2)	0.83908 (12)	0.68440 (12)	0.0204 (4)
C6	0.4554 (3)	0.81778 (18)	0.51496 (17)	0.0199 (5)
C71	0.3517 (3)	0.81299 (19)	0.33254 (18)	0.0243 (6)
C72	0.1785 (3)	0.87697 (18)	0.42704 (18)	0.0217 (6)
C7	0.3065 (3)	0.80477 (17)	0.42642 (17)	0.0175 (5)
C8	0.2430 (3)	0.70802 (17)	0.43343 (17)	0.0177 (5)
C8A	0.2205 (3)	0.68698 (16)	0.53010 (17)	0.0159 (5)
N9	0.1125 (2)	0.61950 (14)	0.52916 (15)	0.0195 (5)
C9A	0.1066 (3)	0.58405 (16)	0.61735 (17)	0.0169 (5)
H2	0.0295	0.4515	0.7512	0.023*
H31A	0.1566	0.5241	0.9070	0.036*
H31B	0.2383	0.6223	0.9064	0.036*
H31C	0.3372	0.5312	0.9002	0.036*
H4	0.3918	0.7043	0.7608	0.019*
H42	0.0112	0.8018	0.6193	0.028*
H43	−0.1312	0.9166	0.6722	0.034*
H45	0.2002	0.9123	0.9361	0.032*
H46	0.3409	0.7965	0.8839	0.026*
H6A	0.5426	0.7768	0.5084	0.024*
H6B	0.4941	0.8816	0.5155	0.024*
H71A	0.4421	0.7718	0.3350	0.037*
H71B	0.3835	0.8762	0.3247	0.037*
H71C	0.2585	0.7963	0.2777	0.037*
H72A	0.0872	0.8711	0.3681	0.033*
H72B	0.2258	0.9382	0.4296	0.033*
H72C	0.1408	0.8678	0.4838	0.033*
H8A	0.1382	0.7004	0.3827	0.021*
H8B	0.3197	0.6632	0.4204	0.021*
H9	0.0478	0.5987	0.4742	0.023*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0643 (3)	0.0205 (2)	0.0551 (2)	0.01212 (14)	0.03881 (18)	0.00133 (14)
N1	0.0265 (12)	0.0141 (11)	0.0202 (11)	−0.0007 (9)	0.0088 (9)	0.0009 (9)
N2	0.0274 (12)	0.0137 (10)	0.0197 (11)	−0.0013 (8)	0.0105 (9)	0.0038 (9)
C3	0.0200 (13)	0.0133 (13)	0.0193 (12)	0.0041 (10)	0.0088 (10)	0.0016 (10)
C31	0.0314 (15)	0.0206 (14)	0.0204 (13)	0.0005 (11)	0.0090 (11)	0.0028 (11)
C3A	0.0173 (13)	0.0126 (12)	0.0220 (13)	0.0020 (9)	0.0054 (10)	0.0002 (10)
C4	0.0198 (13)	0.0135 (12)	0.0150 (12)	0.0009 (10)	0.0045 (9)	0.0001 (10)
C41	0.0236 (13)	0.0105 (12)	0.0206 (12)	−0.0037 (10)	0.0108 (10)	0.0005 (10)
C42	0.0332 (15)	0.0187 (14)	0.0198 (13)	0.0031 (11)	0.0092 (11)	0.0020 (11)
C43	0.0359 (16)	0.0198 (15)	0.0319 (15)	0.0080 (12)	0.0146 (12)	0.0086 (12)
C44	0.0377 (16)	0.0153 (14)	0.0360 (16)	0.0002 (11)	0.0234 (12)	0.0015 (12)
C45	0.0343 (16)	0.0232 (15)	0.0283 (15)	−0.0089 (12)	0.0191 (12)	−0.0089 (12)
C46	0.0232 (14)	0.0220 (14)	0.0219 (13)	−0.0051 (11)	0.0087 (10)	−0.0040 (11)
C4A	0.0197 (12)	0.0093 (12)	0.0174 (12)	0.0023 (9)	0.0068 (9)	0.0002 (9)
C5	0.0156 (12)	0.0113 (12)	0.0221 (13)	0.0058 (9)	0.0051 (10)	0.0018 (10)
O51	0.0209 (9)	0.0179 (9)	0.0213 (9)	−0.0021 (7)	0.0046 (7)	−0.0051 (8)
C6	0.0194 (13)	0.0188 (13)	0.0224 (13)	−0.0034 (10)	0.0075 (10)	−0.0010 (10)
C71	0.0303 (14)	0.0233 (15)	0.0226 (14)	−0.0020 (11)	0.0125 (11)	0.0012 (11)
C72	0.0261 (14)	0.0160 (13)	0.0233 (14)	0.0030 (10)	0.0078 (10)	−0.0003 (11)
C7	0.0207 (13)	0.0131 (12)	0.0199 (13)	−0.0014 (10)	0.0075 (10)	0.0016 (10)
C8	0.0234 (13)	0.0126 (13)	0.0181 (12)	−0.0003 (10)	0.0078 (10)	−0.0005 (10)
C8A	0.0167 (12)	0.0115 (12)	0.0200 (13)	0.0020 (9)	0.0060 (9)	0.0029 (10)
N9	0.0231 (11)	0.0159 (11)	0.0168 (10)	−0.0050 (9)	0.0020 (8)	−0.0002 (9)
C9A	0.0214 (13)	0.0118 (13)	0.0191 (12)	0.0023 (10)	0.0081 (10)	0.0035 (10)

Geometric parameters (Å, º) top

Br1—C44	1.901 (3)	C46—H46	0.9500
N1—C9A	1.329 (3)	C4A—C8A	1.377 (3)
N1—N2	1.368 (3)	C4A—C5	1.442 (3)
N2—C3	1.348 (3)	C5—O51	1.246 (3)
N2—H2	0.8800	C5—C6	1.509 (4)
C3—C3A	1.380 (4)	C6—C7	1.537 (3)
C3—C31	1.492 (3)	C6—H6A	0.9900
C31—H31A	0.9800	C6—H6B	0.9900
C31—H31B	0.9800	C71—C7	1.527 (3)
C31—H31C	0.9800	C71—H71A	0.9800
C3A—C9A	1.395 (3)	C71—H71B	0.9800
C3A—C4	1.503 (3)	C71—H71C	0.9800
C4—C4A	1.522 (3)	C72—C7	1.533 (3)
C4—C41	1.526 (3)	C72—H72A	0.9800
C4—H4	1.0000	C72—H72B	0.9800
C41—C46	1.391 (4)	C72—H72C	0.9800
C41—C42	1.398 (4)	C7—C8	1.531 (3)
C42—C43	1.392 (4)	C8—C8A	1.501 (3)
C42—H42	0.9500	C8—H8A	0.9900
C43—C44	1.381 (4)	C8—H8B	0.9900
C43—H43	0.9500	C8A—N9	1.357 (3)
C44—C45	1.370 (4)	N9—C9A	1.393 (3)
C45—C46	1.391 (4)	N9—H9	0.8800
C45—H45	0.9500

C9A—N1—N2	102.6 (2)	O51—C5—C4A	121.5 (2)
C3—N2—N1	112.9 (2)	O51—C5—C6	119.3 (2)
C3—N2—H2	123.5	C4A—C5—C6	119.2 (2)
N1—N2—H2	123.5	C5—C6—C7	114.0 (2)
N2—C3—C3A	106.8 (2)	C5—C6—H6A	108.8
N2—C3—C31	121.4 (2)	C7—C6—H6A	108.8
C3A—C3—C31	131.8 (2)	C5—C6—H6B	108.8
C3—C31—H31A	109.5	C7—C6—H6B	108.8
C3—C31—H31B	109.5	H6A—C6—H6B	107.7
H31A—C31—H31B	109.5	C7—C71—H71A	109.5
C3—C31—H31C	109.5	C7—C71—H71B	109.5
H31A—C31—H31C	109.5	H71A—C71—H71B	109.5
H31B—C31—H31C	109.5	C7—C71—H71C	109.5
C3—C3A—C9A	103.9 (2)	H71A—C71—H71C	109.5
C3—C3A—C4	134.1 (2)	H71B—C71—H71C	109.5
C9A—C3A—C4	121.9 (2)	C7—C72—H72A	109.5
C3A—C4—C4A	108.1 (2)	C7—C72—H72B	109.5
C3A—C4—C41	110.7 (2)	H72A—C72—H72B	109.5
C4A—C4—C41	112.56 (19)	C7—C72—H72C	109.5
C3A—C4—H4	108.5	H72A—C72—H72C	109.5
C4A—C4—H4	108.5	H72B—C72—H72C	109.5
C41—C4—H4	108.5	C71—C7—C8	108.9 (2)
C46—C41—C42	118.1 (2)	C71—C7—C72	109.2 (2)
C46—C41—C4	121.2 (2)	C8—C7—C72	111.1 (2)
C42—C41—C4	120.6 (2)	C71—C7—C6	111.0 (2)
C43—C42—C41	120.8 (2)	C8—C7—C6	106.7 (2)
C43—C42—H42	119.6	C72—C7—C6	109.9 (2)
C41—C42—H42	119.6	C8A—C8—C7	113.6 (2)
C44—C43—C42	119.2 (3)	C8A—C8—H8A	108.9
C44—C43—H43	120.4	C7—C8—H8A	108.9
C42—C43—H43	120.4	C8A—C8—H8B	108.9
C45—C44—C43	121.5 (3)	C7—C8—H8B	108.9
C45—C44—Br1	119.5 (2)	H8A—C8—H8B	107.7
C43—C44—Br1	119.0 (2)	N9—C8A—C4A	122.2 (2)
C44—C45—C46	119.0 (3)	N9—C8A—C8	114.8 (2)
C44—C45—H45	120.5	C4A—C8A—C8	123.0 (2)
C46—C45—H45	120.5	C8A—N9—C9A	118.3 (2)
C41—C46—C45	121.5 (3)	C8A—N9—H9	120.9
C41—C46—H46	119.3	C9A—N9—H9	120.9
C45—C46—H46	119.3	N1—C9A—N9	123.6 (2)
C8A—C4A—C5	119.1 (2)	N1—C9A—C3A	113.8 (2)
C8A—C4A—C4	123.7 (2)	N9—C9A—C3A	122.5 (2)
C5—C4A—C4	117.2 (2)

C9A—N1—N2—C3	0.1 (3)	C8A—C4A—C5—O51	−179.3 (2)
N1—N2—C3—C3A	0.8 (3)	C4—C4A—C5—O51	0.1 (3)
N1—N2—C3—C31	−177.3 (2)	C8A—C4A—C5—C6	−1.5 (3)
N2—C3—C3A—C9A	−1.3 (3)	C4—C4A—C5—C6	177.9 (2)
C31—C3—C3A—C9A	176.6 (3)	O51—C5—C6—C7	−151.2 (2)
N2—C3—C3A—C4	174.6 (3)	C4A—C5—C6—C7	31.0 (3)
C31—C3—C3A—C4	−7.6 (5)	C5—C6—C7—C71	−172.4 (2)
C3—C3A—C4—C4A	166.0 (3)	C5—C6—C7—C8	−53.8 (3)
C9A—C3A—C4—C4A	−18.8 (3)	C5—C6—C7—C72	66.7 (3)
C3—C3A—C4—C41	−70.3 (3)	C71—C7—C8—C8A	170.5 (2)
C9A—C3A—C4—C41	104.9 (3)	C72—C7—C8—C8A	−69.2 (3)
C3A—C4—C41—C46	104.4 (3)	C6—C7—C8—C8A	50.6 (3)
C4A—C4—C41—C46	−134.5 (2)	C5—C4A—C8A—N9	176.7 (2)
C3A—C4—C41—C42	−73.7 (3)	C4—C4A—C8A—N9	−2.6 (4)
C4A—C4—C41—C42	47.3 (3)	C5—C4A—C8A—C8	−1.4 (4)
C46—C41—C42—C43	0.5 (4)	C4—C4A—C8A—C8	179.2 (2)
C4—C41—C42—C43	178.6 (2)	C7—C8—C8A—N9	156.5 (2)
C41—C42—C43—C44	0.3 (4)	C7—C8—C8A—C4A	−25.2 (3)
C42—C43—C44—C45	−0.8 (4)	C4A—C8A—N9—C9A	−10.2 (3)
C42—C43—C44—Br1	178.8 (2)	C8—C8A—N9—C9A	168.1 (2)
C43—C44—C45—C46	0.4 (4)	N2—N1—C9A—N9	175.2 (2)
Br1—C44—C45—C46	−179.2 (2)	N2—N1—C9A—C3A	−1.0 (3)
C42—C41—C46—C45	−0.9 (4)	C8A—N9—C9A—N1	−168.7 (2)
C4—C41—C46—C45	−179.0 (2)	C8A—N9—C9A—C3A	7.2 (3)
C44—C45—C46—C41	0.4 (4)	C3—C3A—C9A—N1	1.5 (3)
C3A—C4—C4A—C8A	16.1 (3)	C4—C3A—C9A—N1	−175.0 (2)
C41—C4—C4A—C8A	−106.5 (3)	C3—C3A—C9A—N9	−174.7 (2)
C3A—C4—C4A—C5	−163.2 (2)	C4—C3A—C9A—N9	8.8 (4)
C41—C4—C4A—C5	74.2 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O51ⁱ	0.88	1.96	2.824 (3)	168
N9—H9···N1ⁱⁱ	0.88	2.10	2.891 (3)	150

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

Experimental details

Crystal data
Chemical formula	C₁₉H₂₀BrN₃O
M_r	386.29
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	150
a, b, c (Å)	8.6673 (2), 14.6092 (3), 14.4783 (5)
β (°)	107.287 (1)
V (Å³)	1750.46 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	2.36
Crystal size (mm)	0.22 × 0.20 × 0.13

Data collection
Diffractometer	KappaCCD diffractometer
Absorption correction	Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)
T_min, T_max	0.620, 0.757
No. of measured, independent and observed [I > 2σ(I)] reflections	10467, 2971, 2457
R_int	0.041
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.096, 0.98
No. of reflections	2971
No. of parameters	220
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.34, −0.69

Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO-SMN (Otwinowski & Minor, 1997), DENZO-SMN, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976) and PLATON (Spek, 2000), SHELXL97 and WORDPERFECT macro PRPKAPPA (Ferguson, 1999).

Selected geometric parameters (Å, º) top

Br1—C44	1.901 (3)	N2—C3	1.348 (3)
N1—C9A	1.329 (3)	C8A—N9	1.357 (3)
N1—N2	1.368 (3)	N9—C9A	1.393 (3)

C9A—N1—N2	102.6 (2)	C8A—N9—C9A	118.3 (2)
C3—N2—N1	112.9 (2)