4-(2-Fur­yl)-1-(4-methoxy­benz­yl)-1H-pyrazolo[3,4-d]pyrimidine

The title compound, C₁₇H₁₄N₄O₂, is a close analog of potent anti­mycobacterial purines. Mol­ecules are linked by C—H...N hydrogen bonds, forming infinite chains along [010]. The secondary structure is further stabilized by weak intermol­ecular contacts of types C—H...N and C—H...O.

Key indicators

• Single-crystal X-ray study
• T = 112 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.046
• wR factor = 0.135
• Data-to-parameter ratio = 15.2

checkCIF/PLATON results

No syntax errors found



Alert level B
ABSTM02_ALERT_3_B  The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
            Tmin and Tmax reported:      0.661     0.986
            Tmin(prime) and Tmax expected:      0.980     0.986
            RR(prime) =      0.674
            Please check that your absorption correction is appropriate.
PLAT031_ALERT_4_B Refined Extinction Parameter within Range ......       1.80 Sigma
PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large .............       0.67

Alert level C
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        300 Deg.

   0 ALERT level A = In general: serious problem
   3 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

We have discovered that certain 6-aryl-9-benzylpurines are potent antimycobacterials in vitro and may have a potential as antitubercular drugs (Bakkestuen et al., 2000; Gundersen et al., 2002; Bakkestuen et al., 2005; Braendvang & Gundersen, 2005). Compound I was synthesized as a non-purine analog of the previously reported antimycobacterial purines (Braendvang & Gundersen, 2007b).

The molecular geometries are illustrated in Fig. 1 and the bond lengths and angles are listed in Table 1. The angle between the mean plane of the pyrazolo-pyrimidine ring system and the furyl ring are 0.66 (8)°. This coplanarity has also been reported for 6-arylpurines, except that the furyl ring in compound I is rotated approximately 180° compared to previously reported purine structure (Braendvang & Gundersen, 2007a). The orientation of the furyl group is stabilized by intramolecular C3–H3···O18 hydrogen bonding (Table 2). The benzene ring plane is inclined at an angle of 72.83 (7)° to the pyrazolo-pyrimidine ring system, and is very similar as in case of purine ring system previously reported (Braendvang & Gundersen, 2007a).

Fig. 2. shows the molecules in the unit cell. The molecular packing is similar to previous reported purine analog (Braendvang & Gundersen, 2007a), except that the infinite chain along [010] is linked together by hydrogen bonding C21–H21···N2ⁱ [Table 2 and Fig. 2; symmetry code: (i) x, y - 1, z] while in the previous reported structure the hydrogen bonding is between the oxygen in the furyl ring and the H8 in the purine ring.

Related literature

Most bond lengths and angles are in good agreement with those found for 6-furyl- and 6-thienyl-9-benzylpurines (Braendvang & Gundersen, 2007a; Mazumdar et al., 2001), except that the furyl ring in the title compound is rotated by approximately 180°. This orientation of the furyl ring is stabilized by C3—H3···O18 hydrogen bonding.

For related literature, see: Bakkestuen et al. (2000, 2005); Braendvang & Gundersen (2005, 2007b); Gundersen et al. (2002).

S2. Experimental

The title compound was synthesized as described by Brændvang & Gundersen (2007b). Crystals suitable for X-ray diffraction studies were obtained by slow evaporation at room temperature from a mixture of acetone and hexane (1:2).

S3. Refinement

H atoms were positioned geometrically and allowed to ride and rotate (for the CH₃ group) on their carrier atoms, with C—H bond lengths of 0.95 (aromatic C—H), 0.99 (CH₂) or 0.98 Å (CH₃) and with U_iso(H) = 1.2U_eq(C) for methylene and aromatic C—H or 1.5U_eq(C) for CH₃.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and POV-RAY for Windows (Persistence of Vision Pty. Ltd, 2004); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 1999).

Figures

	Fig. 1. The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids for non-H atoms.
	Fig. 2. The packing of (I), viewed down the b axis, showing the infinite chains of (I) along b axis. H atoms have been omitted for clarity.

4-(2-Furyl)-1-(4-methoxybenzyl)-1H-pyrazolo[3,4,d]pyrimidine

Crystal data

C17H14N4O2	Z = 2
Mr = 306.32	F(000) = 320
Triclinic, P1	Dx = 1.424 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.2163 (15) Å	Cell parameters from 2969 reflections
b = 8.4765 (15) Å	θ = 2.8–28.3°
c = 12.437 (2) Å	µ = 0.10 mm^−1
α = 72.485 (3)°	T = 112 K
β = 74.209 (3)°	Block, yellow
γ = 61.065 (3)°	0.20 × 0.20 × 0.15 mm
V = 714.6 (2) Å^3

Data collection

Siemens SMART CCD diffractometer	2422 reflections with I > 2σ(I)
ω scans	Rint = 0.025
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	θmax = 28.8°, θmin = 1.7°
Tmin = 0.661, Tmax = 0.986	h = −10→9
5825 measured reflections	k = −10→11
3187 independent reflections	l = −15→16

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0927P)^2] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.046	(Δ/σ)max < 0.001
wR(F^2) = 0.135	Δρmax = 0.29 e Å^−3
S = 1.03	Δρmin = −0.30 e Å^−3
3187 reflections	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
210 parameters	Extinction coefficient: 0.009 (5)
0 restraints

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C16	0.0212 (2)	1.2299 (2)	1.00299 (13)	0.0310 (4)
H16B	−0.0885	1.2588	1.0631	0.046*
H16A	−0.0199	1.2561	0.93	0.046*
H16C	0.0847	1.3052	0.9974	0.046*
C12	0.3085 (2)	0.9750 (2)	0.95405 (12)	0.0219 (3)
C13	0.3569 (2)	1.0823 (2)	0.85326 (12)	0.0246 (3)
H13	0.2734	1.2083	0.8316	0.03*
C14	0.5284 (2)	1.0031 (2)	0.78483 (12)	0.0243 (3)
H14	0.5622	1.0772	0.7172	0.029*
C9	0.6511 (2)	0.8187 (2)	0.81324 (12)	0.0227 (3)
C10	0.5980 (2)	0.7109 (2)	0.91305 (12)	0.0249 (3)
H10	0.6788	0.5835	0.933	0.03*
C11	0.4287 (2)	0.7889 (2)	0.98257 (12)	0.0254 (3)
H11	0.3944	0.7149	1.0501	0.03*
C8	0.8340 (2)	0.7353 (2)	0.73554 (13)	0.0277 (4)
H8B	0.8838	0.8279	0.7005	0.033*
H8A	0.9272	0.6296	0.7814	0.033*
C3	0.7299 (2)	0.7047 (2)	0.48624 (12)	0.0238 (3)
H3	0.6905	0.7563	0.4133	0.029*
C3A	0.7731 (2)	0.5197 (2)	0.54462 (11)	0.0199 (3)
C4	0.7772 (2)	0.3590 (2)	0.53073 (11)	0.0201 (3)
C6	0.8695 (2)	0.2165 (2)	0.70764 (12)	0.0277 (4)
H6	0.9036	0.1068	0.7644	0.033*
C7A	0.8228 (2)	0.5069 (2)	0.64762 (12)	0.0212 (3)
C17	0.7315 (2)	0.3450 (2)	0.43035 (11)	0.0209 (3)
C19	0.6430 (2)	0.4520 (2)	0.26199 (13)	0.0283 (4)
H19	0.6031	0.5326	0.1925	0.034*
C20	0.6719 (2)	0.2745 (2)	0.29123 (12)	0.0279 (4)
H20	0.6569	0.2094	0.2473	0.033*
C21	0.7291 (2)	0.2044 (2)	0.40082 (12)	0.0249 (3)
H21	0.7595	0.0833	0.4447	0.03*
N1	0.81128 (18)	0.67308 (17)	0.64542 (10)	0.0239 (3)
N2	0.75177 (19)	0.79507 (17)	0.54690 (10)	0.0260 (3)
N5	0.82546 (19)	0.20712 (17)	0.61400 (10)	0.0251 (3)
N7	0.87220 (19)	0.35803 (18)	0.73238 (10)	0.0256 (3)
O15	0.14786 (15)	1.04026 (15)	1.02991 (8)	0.0279 (3)
O18	0.67872 (15)	0.50055 (14)	0.34530 (8)	0.0254 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C16	0.0294 (9)	0.0345 (9)	0.0258 (8)	−0.0120 (8)	−0.0011 (7)	−0.0081 (7)
C12	0.0244 (8)	0.0289 (8)	0.0170 (6)	−0.0158 (7)	−0.0021 (6)	−0.0044 (6)
C13	0.0308 (9)	0.0220 (8)	0.0221 (7)	−0.0144 (7)	−0.0035 (6)	−0.0012 (6)
C14	0.0331 (9)	0.0273 (8)	0.0190 (7)	−0.0208 (7)	−0.0018 (6)	−0.0018 (6)
C9	0.0267 (8)	0.0288 (8)	0.0210 (7)	−0.0172 (7)	−0.0035 (6)	−0.0075 (6)
C10	0.0295 (8)	0.0226 (8)	0.0240 (7)	−0.0118 (7)	−0.0087 (6)	−0.0015 (6)
C11	0.0316 (9)	0.0293 (8)	0.0175 (6)	−0.0183 (7)	−0.0061 (6)	0.0030 (6)
C8	0.0272 (8)	0.0357 (9)	0.0288 (8)	−0.0184 (7)	−0.0011 (6)	−0.0128 (7)
C3	0.0287 (8)	0.0240 (8)	0.0193 (7)	−0.0152 (7)	−0.0024 (6)	0.0000 (6)
C3A	0.0218 (7)	0.0218 (7)	0.0161 (6)	−0.0121 (6)	−0.0004 (5)	−0.0017 (5)
C4	0.0224 (7)	0.0216 (7)	0.0168 (6)	−0.0130 (6)	0.0002 (5)	−0.0012 (5)
C6	0.0370 (9)	0.0261 (8)	0.0181 (7)	−0.0160 (7)	−0.0045 (6)	0.0023 (6)
C7A	0.0225 (8)	0.0243 (8)	0.0183 (7)	−0.0133 (6)	0.0010 (6)	−0.0044 (6)
C17	0.0225 (8)	0.0230 (8)	0.0172 (6)	−0.0135 (6)	−0.0009 (6)	0.0000 (6)
C19	0.0331 (9)	0.0377 (9)	0.0190 (7)	−0.0202 (8)	−0.0055 (6)	−0.0028 (6)
C20	0.0329 (9)	0.0377 (9)	0.0223 (7)	−0.0229 (8)	−0.0005 (6)	−0.0088 (7)
C21	0.0300 (8)	0.0260 (8)	0.0220 (7)	−0.0169 (7)	−0.0008 (6)	−0.0037 (6)
N1	0.0294 (7)	0.0250 (7)	0.0210 (6)	−0.0157 (6)	−0.0024 (5)	−0.0044 (5)
N2	0.0321 (7)	0.0233 (7)	0.0239 (6)	−0.0159 (6)	−0.0029 (5)	−0.0012 (5)
N5	0.0339 (7)	0.0239 (7)	0.0184 (6)	−0.0166 (6)	−0.0032 (5)	0.0009 (5)
N7	0.0327 (7)	0.0269 (7)	0.0176 (6)	−0.0151 (6)	−0.0046 (5)	−0.0007 (5)
O15	0.0262 (6)	0.0327 (6)	0.0193 (5)	−0.0124 (5)	−0.0004 (4)	−0.0016 (4)
O18	0.0357 (6)	0.0242 (6)	0.0185 (5)	−0.0168 (5)	−0.0071 (4)	0.0019 (4)

Geometric parameters (Å, º)

C16—O15	1.423 (2)	C3—N2	1.3199 (19)
C16—H16B	0.98	C3—C3A	1.425 (2)
C16—H16A	0.98	C3—H3	0.95
C16—H16C	0.98	C3A—C7A	1.4063 (19)
C12—O15	1.3669 (18)	C3A—C4	1.407 (2)
C12—C11	1.392 (2)	C4—N5	1.3470 (18)
C12—C13	1.396 (2)	C6—N7	1.336 (2)
C13—C14	1.392 (2)	C6—N5	1.344 (2)
C13—H13	0.95	C6—H6	0.95
C14—C9	1.386 (2)	C7A—N7	1.3437 (18)
C14—H14	0.95	C7A—N1	1.3574 (18)
C9—C10	1.405 (2)	C17—C21	1.358 (2)
N1—C8	1.4610 (18)	C17—O18	1.3793 (16)
C4—C17	1.4494 (19)	C19—C20	1.351 (2)
C8—C9	1.512 (2)	C19—O18	1.3667 (18)
C10—C11	1.385 (2)	C19—H19	0.95
C10—H10	0.95	C20—C21	1.422 (2)
C11—H11	0.95	C20—H20	0.95
C8—H8B	0.99	C21—H21	0.95
C8—H8A	0.99	N1—N2	1.3726 (17)
O15—C16—H16B	109.5	C7A—C3A—C4	115.70 (13)
O15—C16—H16A	109.5	C7A—C3A—C3	104.23 (12)
H16B—C16—H16A	109.5	C4—C3A—C3	140.06 (13)
O15—C16—H16C	109.5	N5—C4—C3A	119.68 (13)
H16B—C16—H16C	109.5	N5—C4—C17	116.53 (13)
H16A—C16—H16C	109.5	C3A—C4—C17	123.80 (13)
O15—C12—C11	115.94 (13)	N7—C6—N5	129.32 (14)
O15—C12—C13	124.37 (14)	N7—C6—H6	115.3
C11—C12—C13	119.68 (14)	N5—C6—H6	115.3
C14—C13—C12	119.47 (14)	N7—C7A—N1	126.44 (13)
C14—C13—H13	120.3	N7—C7A—C3A	126.35 (13)
C12—C13—H13	120.3	N1—C7A—C3A	107.22 (13)
C9—C14—C13	121.45 (14)	C21—C17—O18	110.44 (12)
C9—C14—H14	119.3	C21—C17—C4	132.49 (14)
C13—C14—H14	119.3	O18—C17—C4	117.07 (12)
C14—C9—C10	118.51 (14)	C20—C19—O18	111.19 (13)
C14—C9—C8	120.25 (14)	C20—C19—H19	124.4
C10—C9—C8	121.19 (14)	O18—C19—H19	124.4
C11—C10—C9	120.49 (15)	C19—C20—C21	106.41 (13)
C11—C10—H10	119.8	C19—C20—H20	126.8
C9—C10—H10	119.8	C21—C20—H20	126.8
C10—C11—C12	120.35 (14)	C17—C21—C20	106.38 (13)
C10—C11—H11	119.8	C17—C21—H21	126.8
C12—C11—H11	119.8	C20—C21—H21	126.8
N1—C8—C9	112.29 (12)	C7A—N1—N2	110.83 (12)
N1—C8—H8B	109.1	C7A—N1—C8	128.64 (13)
C9—C8—H8B	109.1	N2—N1—C8	120.17 (12)
N1—C8—H8A	109.1	C3—N2—N1	106.67 (12)
C9—C8—H8A	109.1	C6—N5—C4	117.58 (13)
H8B—C8—H8A	107.9	C6—N7—C7A	111.38 (12)
N2—C3—C3A	111.02 (13)	C12—O15—C16	117.41 (12)
N2—C3—H3	124.5	C19—O18—C17	105.58 (11)
C3A—C3—H3	124.5
O15—C12—C13—C14	177.07 (13)	C3A—C4—C17—O18	−1.0 (2)
C11—C12—C13—C14	−2.6 (2)	O18—C19—C20—C21	0.29 (18)
C12—C13—C14—C9	1.4 (2)	O18—C17—C21—C20	0.04 (17)
C13—C14—C9—C10	0.6 (2)	C4—C17—C21—C20	179.89 (15)
C13—C14—C9—C8	178.30 (13)	C19—C20—C21—C17	−0.20 (17)
C14—C9—C10—C11	−1.5 (2)	N7—C7A—N1—N2	−178.42 (13)
C8—C9—C10—C11	−179.15 (13)	C3A—C7A—N1—N2	1.53 (16)
C9—C10—C11—C12	0.3 (2)	N7—C7A—N1—C8	−5.4 (2)
O15—C12—C11—C10	−177.94 (12)	C3A—C7A—N1—C8	174.58 (14)
C13—C12—C11—C10	1.7 (2)	C9—C8—N1—C7A	−88.40 (19)
C14—C9—C8—N1	−85.88 (17)	C9—C8—N1—N2	84.09 (17)
C10—C9—C8—N1	91.74 (17)	C3A—C3—N2—N1	0.61 (17)
N2—C3—C3A—C7A	0.28 (17)	C7A—N1—N2—C3	−1.34 (16)
N2—C3—C3A—C4	179.00 (18)	C8—N1—N2—C3	−175.07 (13)
C7A—C3A—C4—N5	0.4 (2)	N7—C6—N5—C4	0.4 (3)
C3—C3A—C4—N5	−178.22 (17)	C3A—C4—N5—C6	−0.5 (2)
C7A—C3A—C4—C17	−179.69 (13)	C17—C4—N5—C6	179.62 (13)
C3—C3A—C4—C17	1.7 (3)	N5—C6—N7—C7A	−0.2 (2)
C4—C3A—C7A—N7	−0.2 (2)	N1—C7A—N7—C6	−179.97 (14)
C3—C3A—C7A—N7	178.87 (14)	C3A—C7A—N7—C6	0.1 (2)
C4—C3A—C7A—N1	179.84 (12)	C11—C12—O15—C16	−179.58 (13)
C3—C3A—C7A—N1	−1.08 (16)	C13—C12—O15—C16	0.8 (2)
N5—C4—C17—C21	−0.9 (2)	C20—C19—O18—C17	−0.27 (17)
C3A—C4—C17—C21	179.19 (15)	C21—C17—O18—C19	0.13 (16)
N5—C4—C17—O18	178.94 (12)	C4—C17—O18—C19	−179.74 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C21—H21···N2^i	0.95	2.41	3.338 (2)	164
C16—H16A···N7^ii	0.98	2.60	3.572 (2)	174
C3—H3···O18	0.95	2.60	3.029 (2)	108
C6—H6···O15^iii	0.95	2.51	3.344 (2)	147

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