The title compound, C
19H
20BrN
3O, 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-2
H-pyrazolo[3,4-
b]quinolin-5(6
H)-one compounds which all have identical supramolecular structures.
Supporting information
CCDC reference: 159750
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
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).
H atoms were treated as riding atoms, with C—H = 0.95–1.00 Å and N—H =
0.88 Å.
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).
4-(4-bromophenyl)-3,7,7-trimethyl-4,7,8,9-tetrahydro-2
H-pyrazolo[3,4-
b] quinolin-5(6
H)-one
top
Crystal data top
C19H20BrN3O | Dx = 1.466 Mg m−3 |
Mr = 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 | Rint = 0.041 |
ϕ and ω scans with κ offsets | θmax = 25.0°, θmin = 2.0° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −10→9 |
Tmin = 0.620, Tmax = 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(Fo2) + (0.0565P)2 + 1.064P] where P = (Fo2 + 2Fc2)/3 |
2971 reflections | (Δ/σ)max < 0.001 |
220 parameters | Δρmax = 0.34 e Å−3 |
0 restraints | Δρmin = −0.69 e Å−3 |
Crystal data top
C19H20BrN3O | V = 1750.46 (8) Å3 |
Mr = 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) |
Tmin = 0.620, Tmax = 0.757 | Rint = 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 | Δρmax = 0.34 e Å−3 |
2971 reflections | Δρmin = −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 | Uiso*/Ueq | |
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 |
Mr | 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) |
Tmin, Tmax | 0.620, 0.757 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10467, 2971, 2457 |
Rint | 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 |
Δρmax, Δρmin (e Å−3) | 0.34, −0.69 |
Selected geometric parameters (Å, º) topBr1—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) | | |
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. |
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.