3,7,7-Tri­methyl-4-phenyl-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/S1600536801001477

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3,7,7-Trimethyl-4-phenyl-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, C₁₉H₂₁N₃O, 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.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801001477/na6038sup1.cif Contains datablocks global, 1
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536801001477/na6038Isup2.hkl Contains datablock I

CCDC reference: 159752

checkCIF report

Key indicators

Single-crystal X-ray study
T = 150 K
Mean (C-C) = 0.003 Å
R factor = 0.056
wR factor = 0.148
Data-to-parameter ratio = 17.4

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 antimalarial 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 for the title compound, (I), are given in Table 1 and a view of the molecule is shown in Fig. 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 an corrugated sheet which contains R⁶₆(34) rings This 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 benzaldehyde (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 suitable crystals for diffraction (60% yield, m.p. 502 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).

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

Crystal data top

C₁₉H₂₁N₃O	D_x = 1.281 Mg m⁻³
M_r = 307.39	Melting point: 502 K
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.0870 (5) Å	Cell parameters from 6601 reflections
b = 14.1978 (5) Å	θ = 2.9–27.5°
c = 11.1928 (8) Å	µ = 0.08 mm⁻¹
β = 96.0340 (14)°	T = 150 K
V = 1594.08 (15) Å³	Prism, colourless
Z = 4	0.16 × 0.14 × 0.08 mm
F(000) = 656

Data collection top

Kappa-CCD diffractometer	3681 independent reflections
Radiation source: fine-focus sealed X-ray tube	1960 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.047
ϕ and ω scans with κ offsets	θ_max = 27.6°, θ_min = 3.0°
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	h = −13→13
T_min = 0.987, T_max = 0.994	k = −18→18
23946 measured reflections	l = −14→14

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)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.148	H-atom parameters constrained
S = 0.94	w = 1/[σ²(F_o²) + (0.0733P)²] where P = (F_o² + 2F_c²)/3
3681 reflections	(Δ/σ)_max < 0.001
211 parameters	Δρ_max = 0.26 e Å⁻³
0 restraints	Δρ_min = −0.36 e Å⁻³

Crystal data top

C₁₉H₂₁N₃O	V = 1594.08 (15) Å³
M_r = 307.39	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 10.0870 (5) Å	µ = 0.08 mm⁻¹
b = 14.1978 (5) Å	T = 150 K
c = 11.1928 (8) Å	0.16 × 0.14 × 0.08 mm
β = 96.0340 (14)°

Data collection top

Kappa-CCD diffractometer	3681 independent reflections
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	1960 reflections with I > 2σ(I)
T_min = 0.987, T_max = 0.994	R_int = 0.047
23946 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.056	0 restraints
wR(F²) = 0.148	H-atom parameters constrained
S = 0.94	Δρ_max = 0.26 e Å⁻³
3681 reflections	Δρ_min = −0.36 e Å⁻³
211 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	Occ. (<1)
N1	0.03979 (17)	0.48816 (12)	0.66069 (15)	0.0288 (4)
N2	0.08492 (17)	0.49441 (12)	0.77984 (15)	0.0301 (4)
C3	0.1736 (2)	0.42667 (14)	0.81730 (18)	0.0272 (5)
C3A	0.18685 (19)	0.37042 (14)	0.71874 (17)	0.0248 (5)
C31	0.2363 (2)	0.42237 (16)	0.94324 (18)	0.0372 (6)
C4	0.26485 (19)	0.28267 (13)	0.69798 (17)	0.0253 (5)
C41	0.1994 (2)	0.19599 (14)	0.74721 (17)	0.0253 (5)
C42	0.0970 (2)	0.14951 (14)	0.6799 (2)	0.0309 (5)
C43	0.0345 (2)	0.07262 (15)	0.7259 (2)	0.0365 (6)
C44	0.0739 (2)	0.04152 (16)	0.8410 (2)	0.0405 (6)
C45	0.1757 (2)	0.08656 (15)	0.9089 (2)	0.0388 (6)
C46	0.2388 (2)	0.16331 (14)	0.86258 (19)	0.0319 (5)
C4A	0.27697 (19)	0.27521 (14)	0.56348 (18)	0.0248 (5)
C5	0.37729 (19)	0.21344 (14)	0.52547 (18)	0.0249 (5)
O51	0.45326 (13)	0.16825 (10)	0.59917 (12)	0.0309 (4)
C6	0.39161 (19)	0.20477 (15)	0.39318 (18)	0.0294 (5)
C7	0.2616 (2)	0.21729 (14)	0.31167 (17)	0.0264 (5)
C71	0.2881 (2)	0.22044 (16)	0.17987 (18)	0.0353 (6)
C72	0.1679 (2)	0.13499 (15)	0.3284 (2)	0.0352 (6)
C8A	0.19262 (19)	0.32104 (13)	0.47854 (18)	0.0245 (5)
C8	0.1995 (2)	0.31012 (14)	0.34582 (17)	0.0291 (5)
N9	0.09775 (16)	0.38222 (12)	0.50788 (14)	0.0286 (4)
C9A	0.10411 (19)	0.41232 (14)	0.62706 (18)	0.0260 (5)
H2	0.0587	0.5384	0.8276	0.036*
H31A	0.2159	0.4802	0.9854	0.056*	0.50
H31B	0.3330	0.4160	0.9437	0.056*	0.50
H31C	0.2012	0.3680	0.9838	0.056*	0.50
H31D	0.2842	0.3626	0.9565	0.056*	0.50
H31E	0.1671	0.4268	0.9982	0.056*	0.50
H31F	0.2989	0.4748	0.9581	0.056*	0.50
H4	0.3564	0.2895	0.7410	0.030*
H42	0.0689	0.1706	0.6008	0.037*
H43	−0.0355	0.0413	0.6781	0.044*
H44	0.0306	−0.0108	0.8730	0.049*
H45	0.2034	0.0652	0.9880	0.047*
H46	0.3096	0.1938	0.9103	0.038*
H6A	0.4289	0.1419	0.3779	0.035*
H6B	0.4563	0.2526	0.3713	0.035*
H71A	0.3314	0.1618	0.1590	0.053*
H71B	0.3464	0.2739	0.1670	0.053*
H71C	0.2035	0.2276	0.1291	0.053*
H72A	0.2097	0.0761	0.3060	0.053*
H72B	0.0840	0.1443	0.2772	0.053*
H72C	0.1500	0.1317	0.4127	0.053*
H8A	0.2522	0.3628	0.3173	0.035*
H8B	0.1082	0.3146	0.3040	0.035*
H9	0.0345	0.4022	0.4537	0.034*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0358 (10)	0.0259 (10)	0.0242 (10)	0.0021 (8)	0.0004 (8)	−0.0023 (8)
N2	0.0394 (11)	0.0260 (10)	0.0252 (10)	−0.0006 (8)	0.0045 (8)	−0.0040 (8)
C3	0.0309 (11)	0.0244 (11)	0.0259 (12)	−0.0041 (10)	0.0009 (9)	0.0015 (9)
C3A	0.0258 (11)	0.0243 (11)	0.0239 (11)	−0.0021 (9)	0.0011 (9)	0.0013 (9)
C31	0.0477 (14)	0.0353 (13)	0.0277 (13)	−0.0035 (11)	−0.0004 (11)	−0.0030 (10)
C4	0.0257 (11)	0.0263 (11)	0.0229 (11)	−0.0002 (9)	−0.0019 (9)	0.0014 (9)
C41	0.0290 (11)	0.0239 (11)	0.0240 (12)	0.0061 (9)	0.0067 (9)	−0.0003 (9)
C42	0.0332 (12)	0.0329 (13)	0.0265 (12)	−0.0004 (10)	0.0033 (10)	0.0005 (10)
C43	0.0416 (13)	0.0312 (13)	0.0372 (14)	−0.0090 (11)	0.0067 (11)	−0.0029 (11)
C44	0.0548 (16)	0.0268 (12)	0.0421 (15)	−0.0016 (11)	0.0151 (13)	0.0025 (11)
C45	0.0560 (15)	0.0317 (13)	0.0297 (13)	0.0076 (12)	0.0092 (12)	0.0060 (11)
C46	0.0386 (13)	0.0291 (12)	0.0278 (12)	0.0026 (10)	0.0028 (10)	0.0014 (10)
C4A	0.0250 (11)	0.0250 (11)	0.0244 (11)	−0.0014 (9)	0.0024 (9)	0.0010 (9)
C5	0.0226 (10)	0.0236 (11)	0.0283 (12)	−0.0036 (9)	0.0008 (9)	0.0020 (9)
O51	0.0306 (8)	0.0309 (9)	0.0304 (9)	0.0041 (7)	−0.0001 (7)	0.0058 (7)
C6	0.0270 (11)	0.0337 (12)	0.0280 (12)	0.0025 (10)	0.0045 (9)	0.0015 (10)
C7	0.0287 (11)	0.0270 (11)	0.0232 (12)	0.0009 (9)	0.0009 (9)	−0.0014 (9)
C71	0.0364 (12)	0.0415 (14)	0.0275 (12)	0.0024 (11)	0.0013 (10)	−0.0027 (10)
C72	0.0366 (13)	0.0312 (13)	0.0373 (14)	−0.0014 (10)	0.0009 (10)	−0.0030 (10)
C8A	0.0257 (11)	0.0203 (11)	0.0272 (12)	−0.0006 (9)	0.0018 (9)	−0.0013 (9)
C8	0.0336 (12)	0.0293 (12)	0.0240 (12)	0.0018 (10)	0.0008 (9)	0.0021 (9)
N9	0.0295 (10)	0.0314 (10)	0.0233 (10)	0.0057 (8)	−0.0048 (8)	−0.0036 (8)
C9A	0.0285 (11)	0.0225 (11)	0.0267 (12)	−0.0023 (9)	0.0023 (9)	−0.0021 (9)

Geometric parameters (Å, º) top

N1—C9A	1.332 (2)	C45—C46	1.389 (3)
N1—N2	1.366 (2)	C45—H45	0.9500
N2—C3	1.350 (3)	C46—H46	0.9500
N2—H2	0.8800	C4A—C8A	1.371 (3)
C3—C3A	1.380 (3)	C4A—C5	1.437 (3)
C3—C31	1.484 (3)	C5—O51	1.244 (2)
C3A—C9A	1.387 (3)	C5—C6	1.508 (3)
C3A—C4	1.505 (3)	C6—C7	1.527 (3)
C31—H31A	0.9800	C6—H6A	0.9900
C31—H31B	0.9800	C6—H6B	0.9900
C31—H31C	0.9800	C7—C8	1.525 (3)
C31—H31D	0.9800	C7—C72	1.526 (3)
C31—H31E	0.9800	C7—C71	1.527 (3)
C31—H31F	0.9800	C71—H71A	0.9800
C4—C41	1.526 (3)	C71—H71B	0.9800
C4—C4A	1.527 (3)	C71—H71C	0.9800
C4—H4	1.0000	C72—H72A	0.9800
C41—C42	1.381 (3)	C72—H72B	0.9800
C41—C46	1.390 (3)	C72—H72C	0.9800
C42—C43	1.386 (3)	C8A—N9	1.358 (2)
C42—H42	0.9500	C8A—C8	1.502 (3)
C43—C44	1.381 (3)	C8—H8A	0.9900
C43—H43	0.9500	C8—H8B	0.9900
C44—C45	1.370 (3)	N9—C9A	1.396 (2)
C44—H44	0.9500	N9—H9	0.8800

C9A—N1—N2	101.9 (2)	C44—C45—H45	119.8
C3—N2—N1	113.5 (2)	C46—C45—H45	119.8
C3—N2—H2	123.2	C45—C46—C41	120.8 (2)
N1—N2—H2	123.2	C45—C46—H46	119.6
N2—C3—C3A	106.32 (18)	C41—C46—H46	119.6
N2—C3—C31	121.77 (18)	C8A—C4A—C5	119.29 (18)
C3A—C3—C31	131.91 (19)	C8A—C4A—C4	122.85 (17)
C3—C3A—C9A	103.99 (18)	C5—C4A—C4	117.78 (17)
C3—C3A—C4	134.35 (19)	O51—C5—C4A	121.50 (19)
C9A—C3A—C4	121.65 (18)	O51—C5—C6	119.57 (18)
C3—C31—H31A	109.5	C4A—C5—C6	118.93 (18)
C3—C31—H31B	109.5	C5—C6—C7	114.34 (16)
H31A—C31—H31B	109.5	C5—C6—H6A	108.7
C3—C31—H31C	109.5	C7—C6—H6A	108.7
H31A—C31—H31C	109.5	C5—C6—H6B	108.7
H31B—C31—H31C	109.5	C7—C6—H6B	108.7
C3—C31—H31D	109.5	H6A—C6—H6B	107.6
H31A—C31—H31D	141.1	C8—C7—C72	110.80 (16)
H31B—C31—H31D	56.3	C8—C7—C71	109.57 (17)
H31C—C31—H31D	56.3	C72—C7—C71	108.32 (17)
C3—C31—H31E	109.5	C8—C7—C6	107.48 (17)
H31A—C31—H31E	56.3	C72—C7—C6	109.96 (17)
H31B—C31—H31E	141.1	C71—C7—C6	110.71 (16)
H31C—C31—H31E	56.3	C7—C71—H71A	109.5
H31D—C31—H31E	109.5	C7—C71—H71B	109.5
C3—C31—H31F	109.5	H71A—C71—H71B	109.5
H31A—C31—H31F	56.3	C7—C71—H71C	109.5
H31B—C31—H31F	56.3	H71A—C71—H71C	109.5
H31C—C31—H31F	141.1	H71B—C71—H71C	109.5
H31D—C31—H31F	109.5	C7—C72—H72A	109.5
H31E—C31—H31F	109.5	C7—C72—H72B	109.5
C3A—C4—C41	111.04 (15)	H72A—C72—H72B	109.5
C3A—C4—C4A	107.88 (16)	C7—C72—H72C	109.5
C41—C4—C4A	112.48 (16)	H72A—C72—H72C	109.5
C3A—C4—H4	108.4	H72B—C72—H72C	109.5
C41—C4—H4	108.4	N9—C8A—C4A	122.51 (18)
C4A—C4—H4	108.4	N9—C8A—C8	114.33 (17)
C42—C41—C46	118.1 (2)	C4A—C8A—C8	123.14 (18)
C42—C41—C4	121.03 (18)	C8A—C8—C7	113.56 (17)
C46—C41—C4	120.82 (19)	C8A—C8—H8A	108.9
C41—C42—C43	121.2 (2)	C7—C8—H8A	108.9
C41—C42—H42	119.4	C8A—C8—H8B	108.9
C43—C42—H42	119.4	C7—C8—H8B	108.9
C44—C43—C42	120.0 (2)	H8A—C8—H8B	107.7
C44—C43—H43	120.0	C8A—N9—C9A	117.66 (17)
C42—C43—H43	120.0	C8A—N9—H9	121.2
C45—C44—C43	119.6 (2)	C9A—N9—H9	121.2
C45—C44—H44	120.2	N1—C9A—C3A	114.26 (18)
C43—C44—H44	120.2	N1—C9A—N9	122.9 (2)
C44—C45—C46	120.3 (2)	C3A—C9A—N9	122.65 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O51ⁱ	0.88	2.03	2.861 (2)	158
N9—H9···N1ⁱⁱ	0.88	2.10	2.885 (2)	148

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

Experimental details

Crystal data
Chemical formula	C₁₉H₂₁N₃O
M_r	307.39
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	150
a, b, c (Å)	10.0870 (5), 14.1978 (5), 11.1928 (8)
β (°)	96.0340 (14)
V (Å³)	1594.08 (15)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.16 × 0.14 × 0.08

Data collection
Diffractometer	Kappa-CCD diffractometer
Absorption correction	Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)
T_min, T_max	0.987, 0.994
No. of measured, independent and observed [I > 2σ(I)] reflections	23946, 3681, 1960
R_int	0.047
(sin θ/λ)_max (Å⁻¹)	0.653

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.056, 0.148, 0.94
No. of reflections	3681
No. of parameters	211
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.26, −0.36

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

N1—C9A	1.332 (2)	C8A—N9	1.358 (2)
N1—N2	1.366 (2)	N9—C9A	1.396 (2)
N2—C3	1.350 (3)

C9A—N1—N2	101.9 (2)	N1—C9A—N9	122.9 (2)
C3—N2—N1	113.5 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O51ⁱ	0.88	2.03	2.861 (2)	158
N9—H9···N1ⁱⁱ	0.88	2.10	2.885 (2)	148

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

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