Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807022647/xu2252sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807022647/xu2252Isup2.hkl |
CCDC reference: 651527
Key indicators
- Single-crystal X-ray study
- T = 112 K
- Mean (C-C) = 0.002 Å
- R factor = 0.036
- wR factor = 0.094
- Data-to-parameter ratio = 17.0
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: 0.642 0.952 Tmin(prime) and Tmax expected: 0.928 0.952 RR(prime) = 0.692 Please check that your absorption correction is appropriate. PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large ............. 0.69
Alert level C PLAT480_ALERT_4_C Long H...A H-Bond Reported H8 .. O18 .. 2.66 Ang.
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 0 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
Bond lengths and angles in the title compound, (I), are in good agreement with those found for 6-furyl- and 6-thienyl-9-benzyl-purines (Braendvang & Gundersen, 2007a; Mazumdar et al., 2001), and also with the recently reported non-purine analog 4-(2-furyl)-1-[(4-methoxyphenyl)methyl]-1H-pyrazolo[3,4–d]pyrimidine (Braendvang & Gundersen, 2007b). The molecular packing as well as the orientation of the furyl ring and benzene ring very much resemble the recently reported analog 2-chloro-6-(2-furanyl)-9-[(4-methoxyphenyl)methyl]-9H-purine, (II) (Braendvang & Gundersen, 2007a).
For related literature, see: Bakkestuen et al. (2000, 2005); Braendvang & Gundersen (2005); Gundersen et al. (2002); Liebeskind & Wang (1993).
The title compound was synthesized by regioselective Stille coupling using benzofur-2-yl stannane as described for compound (II) (Bakkestuen et al., 2005). The benzofur-2-yl stannane used was made by literature procedure (Liebeskind & Wang, 1993). Crystals suitable for X-ray diffraction studies were obtained from a solution of title compound (27 mg) in CH2Cl2 (0.8 ml) with a top layer of heptane (0.8 ml).
H atoms were positioned geometrically and allowed to ride and rotate (for the CH3 group) on their carrier atoms, with C—H = 0.95 (aromatic), 0.99 (CH2) or 0.98 Å (CH3) and with Uiso(H) = 1.2Ueq(C) for CH2 and aromatic, or 1.5Ueq(C) for CH3.
We have discovered that certain 6-aryl-9-benzylpurines are potent antimycobacterials in vitro and may have a potensial as antitubercular drugs (Bakkestuen et al., 2000; Gundersen et al., 2002; Bakkestuen et al., 2005; Braendvang & Gundersen, 2005). The title compound, (I), was synthesized as a close analog of the previously reported antimycobacterial 2-chloro-6-(2-furanyl)-9-[(4-methoxyphenyl)methyl]-9H-purine, (II), (Bakkestuen et al., 2005).
The molecular geometries is illustrated in Fig. 1. The selected bond lenghts and angles are listed in Table 1 and compared with the recently reported X-ray structure of compound (II) (Braendvang & Gundersen, 2007a). There are only small differences in bond lenghts and angles in these two compounds, specially molecule A in compound (II) resembles the title compound (I) (Table 1). In compound (I) the angle between the mean plane of the purine ring system and the furyl ring C17/O18/C19—C21 is 4.49 (7)°, or 4.82 (5)° if the mean plane of benzofuryl is used. In compound (II) the angles were 2.31 (6)° in molecule A and 2.79 (5)° in molecule B.
The positions of the benzyl groups are only slightly different in compound (I) and (II) as seen from the torsion angles C4—N9—C10—C11 and N9—C10—C11—C12 (Table 1). The benzene ring C11—C16 is inclined at an angle of 70.68 (6)° to the purine ring in compound (I). Previously reported for compound (II) is 73.64 (5)° in molecule A and 77.80 (4)° in molecule B.
Fig. 2 shows the crystal packing of (I) in the unit cell. The conformation adopted by the benzene rings allows for simultaneous C—H···π interactions, and π–π interactions to form dimers of molecules (Fig. 3). The C—H···π interactions occurs between the C26—H26···Cg1i (Table 2) (Cg1 is the centroid of the benzene ring C11—C16) [symmetry code: (i) 2 - x, 1 - y, 1 - z]. In these dimers, π–π interactions occurs between the purine ring system and the benzene ring C19/C20/C24—C27 in the benzofuryl group. In this interaction the benzene ring C19/C20/C24—C27 and the pyrimidine ring N1/C2/N3/C4—C6 are slipped by 18.7 ° relative to their ring perpendiculars (the average interplanar distance between the benzene ring in the benzofuryl group and the pyrimidine ring N1/C2/N3/C4—C6 is 3.339 Å), the ring-centroid to ring-centroid distance being 3.5277 (10) Å. The average interplanar distance between the benzene ring in the benzofuryl group and the imidazole ring C4/C5/N7/C8/N9 is 3.424 Å (the two rings are slipped by 22.8° relative to their ring perpendiculars), the ring-centroid to ring-centroid distance being 3.7161 (10) Å.
The crystal packing (Fig. 2) gives further π–π interactions between the imidazole ring (C4A—N9A) and the furyl ring C17/O18/C19—C21iii, the ring-centroid to centroid distance is 3.5084 (10) Å [symmetry code: (iii) 1 - x, 1 - y, 1 - z]. In this interaction the average interplanar distance is 3.318 Å and the two rings are slipped by 19.0° relative to their ring perpendiculars.
Finally, the orientation of the furyl group in compound (I) is stabilized by weak C8—H8···O18ii hydrogen bonding, forming infinite chains of molecules (Table 2 and Fig. 3) [symmetry code: (ii) x - 1, y, z - 1].
The molecular packing of compound (I) in overall is very similar to the previous reported (II) (Braendvang & Gundersen, 2007a).
Bond lengths and angles in the title compound, (I), are in good agreement with those found for 6-furyl- and 6-thienyl-9-benzyl-purines (Braendvang & Gundersen, 2007a; Mazumdar et al., 2001), and also with the recently reported non-purine analog 4-(2-furyl)-1-[(4-methoxyphenyl)methyl]-1H-pyrazolo[3,4–d]pyrimidine (Braendvang & Gundersen, 2007b). The molecular packing as well as the orientation of the furyl ring and benzene ring very much resemble the recently reported analog 2-chloro-6-(2-furanyl)-9-[(4-methoxyphenyl)methyl]-9H-purine, (II) (Braendvang & Gundersen, 2007a).
For related literature, see: Bakkestuen et al. (2000, 2005); Braendvang & Gundersen (2005); Gundersen et al. (2002); Liebeskind & Wang (1993).
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 (Version 1.08; 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).
C21H15ClN4O2 | F(000) = 808 |
Mr = 390.82 | Dx = 1.476 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 7413 reflections |
a = 8.0721 (8) Å | θ = 2.8–28.9° |
b = 28.668 (3) Å | µ = 0.24 mm−1 |
c = 8.3764 (9) Å | T = 112 K |
β = 114.876 (2)° | Block, colourless |
V = 1758.6 (3) Å3 | 0.3 × 0.2 × 0.2 mm |
Z = 4 |
Siemens SMART CCD diffractometer | 3366 reflections with I > 2σ(I) |
Sets of exposures each taken over 0.3° ω rotation scans | Rint = 0.044 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | θmax = 29.1°, θmin = 1.4° |
Tmin = 0.642, Tmax = 0.952 | h = −10→10 |
16890 measured reflections | k = −38→39 |
4334 independent reflections | l = −10→11 |
Refinement on F2 | H-atom parameters constrained |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0518P)2 + 0.2117P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.036 | (Δ/σ)max = 0.001 |
wR(F2) = 0.094 | Δρmax = 0.31 e Å−3 |
S = 1.03 | Δρmin = −0.23 e Å−3 |
4334 reflections | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
255 parameters | Extinction coefficient: 0.0045 (10) |
0 restraints |
C21H15ClN4O2 | V = 1758.6 (3) Å3 |
Mr = 390.82 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.0721 (8) Å | µ = 0.24 mm−1 |
b = 28.668 (3) Å | T = 112 K |
c = 8.3764 (9) Å | 0.3 × 0.2 × 0.2 mm |
β = 114.876 (2)° |
Siemens SMART CCD diffractometer | 4334 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 3366 reflections with I > 2σ(I) |
Tmin = 0.642, Tmax = 0.952 | Rint = 0.044 |
16890 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 0 restraints |
wR(F2) = 0.094 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.31 e Å−3 |
4334 reflections | Δρmin = −0.23 e Å−3 |
255 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C23 | 0.4460 (2) | 0.75117 (6) | −0.4061 (2) | 0.0304 (3) | |
H23C | 0.4944 | 0.7779 | −0.4457 | 0.046* | |
H23B | 0.3129 | 0.7501 | −0.4719 | 0.046* | |
H23A | 0.4994 | 0.7224 | −0.4266 | 0.046* | |
C14 | 0.42248 (18) | 0.72315 (5) | −0.14688 (19) | 0.0219 (3) | |
C15 | 0.33819 (19) | 0.68194 (5) | −0.22890 (18) | 0.0220 (3) | |
H15 | 0.326 | 0.6747 | −0.344 | 0.026* | |
C16 | 0.27211 (19) | 0.65160 (5) | −0.14000 (18) | 0.0224 (3) | |
H16 | 0.213 | 0.6237 | −0.1964 | 0.027* | |
C11 | 0.29012 (18) | 0.66101 (5) | 0.02899 (18) | 0.0206 (3) | |
C12 | 0.3764 (2) | 0.70225 (5) | 0.1092 (2) | 0.0256 (3) | |
H12 | 0.3907 | 0.7092 | 0.2251 | 0.031* | |
C13 | 0.4416 (2) | 0.73323 (5) | 0.0223 (2) | 0.0270 (3) | |
H13 | 0.4993 | 0.7613 | 0.0782 | 0.032* | |
C10 | 0.21757 (19) | 0.62721 (5) | 0.1228 (2) | 0.0251 (3) | |
H10B | 0.1899 | 0.6444 | 0.2111 | 0.03* | |
H10A | 0.1022 | 0.6134 | 0.0364 | 0.03* | |
C8 | 0.3488 (2) | 0.54524 (5) | 0.14963 (19) | 0.0248 (3) | |
H8 | 0.2588 | 0.5346 | 0.04 | 0.03* | |
C5 | 0.58017 (18) | 0.54779 (4) | 0.39524 (17) | 0.0190 (3) | |
C6 | 0.73824 (18) | 0.54209 (4) | 0.55173 (17) | 0.0182 (3) | |
C2 | 0.70456 (19) | 0.61808 (5) | 0.61788 (18) | 0.0198 (3) | |
C4 | 0.49637 (18) | 0.59170 (5) | 0.36956 (18) | 0.0192 (3) | |
C17 | 0.84136 (18) | 0.49884 (4) | 0.59799 (18) | 0.0185 (3) | |
C21 | 0.82115 (18) | 0.45845 (4) | 0.50752 (18) | 0.0201 (3) | |
H21 | 0.7293 | 0.4516 | 0.3937 | 0.024* | |
C20 | 0.96580 (18) | 0.42808 (5) | 0.61741 (18) | 0.0192 (3) | |
C24 | 1.02383 (19) | 0.38258 (5) | 0.60394 (19) | 0.0223 (3) | |
H24 | 0.9607 | 0.3644 | 0.5013 | 0.027* | |
C25 | 1.1748 (2) | 0.36497 (5) | 0.74343 (19) | 0.0240 (3) | |
H25 | 1.2162 | 0.3344 | 0.7357 | 0.029* | |
C26 | 1.2679 (2) | 0.39127 (5) | 0.8958 (2) | 0.0246 (3) | |
H26 | 1.3708 | 0.378 | 0.9897 | 0.03* | |
C27 | 1.2137 (2) | 0.43633 (5) | 0.91346 (19) | 0.0244 (3) | |
H27 | 1.2763 | 0.4543 | 1.0168 | 0.029* | |
C19 | 1.06353 (18) | 0.45333 (4) | 0.77165 (18) | 0.0199 (3) | |
N9 | 0.34760 (15) | 0.58943 (4) | 0.21140 (15) | 0.0211 (3) | |
N7 | 0.48406 (16) | 0.51863 (4) | 0.25380 (15) | 0.0235 (3) | |
N1 | 0.80044 (15) | 0.57858 (4) | 0.66414 (15) | 0.0194 (2) | |
N3 | 0.55232 (16) | 0.62840 (4) | 0.47883 (15) | 0.0204 (2) | |
O22 | 0.49164 (14) | 0.75576 (3) | −0.22214 (14) | 0.0290 (2) | |
O18 | 0.98871 (13) | 0.49710 (3) | 0.76115 (12) | 0.0209 (2) | |
Cl2 | 0.79826 (5) | 0.664269 (11) | 0.76375 (5) | 0.02636 (11) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C23 | 0.0249 (8) | 0.0330 (8) | 0.0319 (8) | 0.0020 (6) | 0.0106 (7) | 0.0137 (7) |
C14 | 0.0175 (7) | 0.0184 (6) | 0.0280 (7) | 0.0015 (5) | 0.0078 (6) | 0.0063 (5) |
C15 | 0.0217 (7) | 0.0208 (7) | 0.0216 (7) | 0.0009 (5) | 0.0071 (6) | 0.0026 (5) |
C16 | 0.0201 (7) | 0.0171 (6) | 0.0253 (7) | −0.0006 (5) | 0.0049 (6) | 0.0029 (5) |
C11 | 0.0151 (6) | 0.0217 (7) | 0.0230 (7) | 0.0038 (5) | 0.0061 (5) | 0.0069 (5) |
C12 | 0.0252 (8) | 0.0272 (7) | 0.0242 (7) | 0.0012 (6) | 0.0101 (6) | −0.0005 (6) |
C13 | 0.0277 (8) | 0.0196 (7) | 0.0313 (8) | −0.0036 (6) | 0.0100 (7) | −0.0031 (6) |
C10 | 0.0174 (7) | 0.0273 (7) | 0.0278 (8) | 0.0036 (6) | 0.0066 (6) | 0.0109 (6) |
C8 | 0.0247 (7) | 0.0228 (7) | 0.0230 (7) | −0.0054 (6) | 0.0063 (6) | 0.0021 (5) |
C5 | 0.0196 (7) | 0.0170 (6) | 0.0214 (7) | −0.0017 (5) | 0.0096 (6) | 0.0031 (5) |
C6 | 0.0185 (7) | 0.0173 (6) | 0.0202 (7) | −0.0005 (5) | 0.0094 (6) | 0.0027 (5) |
C2 | 0.0209 (7) | 0.0185 (6) | 0.0215 (7) | 0.0005 (5) | 0.0104 (6) | 0.0011 (5) |
C4 | 0.0169 (6) | 0.0203 (6) | 0.0211 (7) | 0.0002 (5) | 0.0087 (6) | 0.0052 (5) |
C17 | 0.0170 (6) | 0.0186 (6) | 0.0192 (7) | −0.0011 (5) | 0.0069 (5) | 0.0032 (5) |
C21 | 0.0194 (7) | 0.0194 (6) | 0.0203 (7) | −0.0012 (5) | 0.0072 (6) | 0.0017 (5) |
C20 | 0.0192 (7) | 0.0172 (6) | 0.0224 (7) | −0.0013 (5) | 0.0099 (6) | 0.0017 (5) |
C24 | 0.0234 (7) | 0.0181 (6) | 0.0276 (7) | −0.0025 (5) | 0.0128 (6) | −0.0012 (5) |
C25 | 0.0255 (8) | 0.0163 (6) | 0.0352 (8) | 0.0025 (5) | 0.0178 (7) | 0.0039 (6) |
C26 | 0.0213 (7) | 0.0236 (7) | 0.0287 (8) | 0.0047 (5) | 0.0103 (6) | 0.0079 (6) |
C27 | 0.0248 (7) | 0.0218 (7) | 0.0239 (7) | 0.0011 (6) | 0.0077 (6) | 0.0015 (6) |
C19 | 0.0216 (7) | 0.0153 (6) | 0.0253 (7) | 0.0010 (5) | 0.0123 (6) | 0.0029 (5) |
N9 | 0.0184 (6) | 0.0206 (6) | 0.0218 (6) | −0.0006 (4) | 0.0061 (5) | 0.0051 (4) |
N7 | 0.0238 (6) | 0.0197 (6) | 0.0230 (6) | −0.0033 (5) | 0.0058 (5) | 0.0020 (5) |
N1 | 0.0200 (6) | 0.0178 (5) | 0.0215 (6) | 0.0013 (4) | 0.0097 (5) | 0.0019 (4) |
N3 | 0.0204 (6) | 0.0189 (6) | 0.0224 (6) | 0.0015 (4) | 0.0094 (5) | 0.0026 (4) |
O22 | 0.0292 (6) | 0.0234 (5) | 0.0328 (6) | −0.0054 (4) | 0.0115 (5) | 0.0074 (4) |
O18 | 0.0216 (5) | 0.0161 (5) | 0.0214 (5) | 0.0033 (4) | 0.0053 (4) | 0.0015 (4) |
Cl2 | 0.0269 (2) | 0.01996 (17) | 0.02673 (19) | 0.00263 (13) | 0.00591 (15) | −0.00372 (13) |
C23—O22 | 1.4318 (19) | C5—C6 | 1.4022 (19) |
C23—H23C | 0.98 | C6—N1 | 1.3548 (17) |
C23—H23B | 0.98 | C6—C17 | 1.4521 (18) |
C23—H23A | 0.98 | C2—N3 | 1.3229 (18) |
C14—O22 | 1.3708 (16) | C2—N1 | 1.3338 (17) |
C14—C13 | 1.390 (2) | C2—Cl2 | 1.7439 (14) |
C14—C15 | 1.3918 (19) | C4—N3 | 1.3420 (17) |
C15—C16 | 1.3892 (19) | C4—N9 | 1.3650 (18) |
C15—H15 | 0.95 | C17—C21 | 1.3556 (19) |
C16—C11 | 1.387 (2) | C17—O18 | 1.3847 (16) |
C16—H16 | 0.95 | C21—C20 | 1.4368 (18) |
C11—C12 | 1.393 (2) | C21—H21 | 0.95 |
C11—C10 | 1.5122 (19) | C20—C19 | 1.3994 (19) |
C12—C13 | 1.385 (2) | C20—C24 | 1.4064 (19) |
C12—H12 | 0.95 | C24—C25 | 1.381 (2) |
C13—H13 | 0.95 | C24—H24 | 0.95 |
C10—N9 | 1.4732 (17) | C25—C26 | 1.398 (2) |
C10—H10B | 0.99 | C25—H25 | 0.95 |
C10—H10A | 0.99 | C26—C27 | 1.3914 (19) |
C8—N7 | 1.3169 (18) | C26—H26 | 0.95 |
C8—N9 | 1.3699 (18) | C27—C19 | 1.3810 (19) |
C8—H8 | 0.95 | C27—H27 | 0.95 |
C5—N7 | 1.3896 (18) | C19—O18 | 1.3790 (15) |
C5—C4 | 1.4021 (18) | ||
O22—C23—H23C | 109.5 | N3—C2—N1 | 131.02 (13) |
O22—C23—H23B | 109.5 | N3—C2—Cl2 | 114.55 (10) |
H23C—C23—H23B | 109.5 | N1—C2—Cl2 | 114.42 (10) |
O22—C23—H23A | 109.5 | N3—C4—N9 | 127.27 (12) |
H23C—C23—H23A | 109.5 | N3—C4—C5 | 126.66 (12) |
H23B—C23—H23A | 109.5 | N9—C4—C5 | 106.07 (12) |
O22—C14—C13 | 115.79 (12) | C21—C17—O18 | 111.86 (11) |
O22—C14—C15 | 124.13 (13) | C21—C17—C6 | 131.26 (13) |
C13—C14—C15 | 120.09 (13) | O18—C17—C6 | 116.88 (11) |
C16—C15—C14 | 119.02 (13) | C17—C21—C20 | 106.57 (12) |
C16—C15—H15 | 120.5 | C17—C21—H21 | 126.7 |
C14—C15—H15 | 120.5 | C20—C21—H21 | 126.7 |
C11—C16—C15 | 121.73 (13) | C19—C20—C24 | 118.46 (12) |
C11—C16—H16 | 119.1 | C19—C20—C21 | 105.57 (11) |
C15—C16—H16 | 119.1 | C24—C20—C21 | 135.97 (13) |
C16—C11—C12 | 118.28 (13) | C25—C24—C20 | 118.44 (13) |
C16—C11—C10 | 120.54 (13) | C25—C24—H24 | 120.8 |
C12—C11—C10 | 121.17 (13) | C20—C24—H24 | 120.8 |
C13—C12—C11 | 120.94 (14) | C24—C25—C26 | 121.29 (13) |
C13—C12—H12 | 119.5 | C24—C25—H25 | 119.4 |
C11—C12—H12 | 119.5 | C26—C25—H25 | 119.4 |
C12—C13—C14 | 119.92 (13) | C27—C26—C25 | 121.69 (13) |
C12—C13—H13 | 120 | C27—C26—H26 | 119.2 |
C14—C13—H13 | 120 | C25—C26—H26 | 119.2 |
N9—C10—C11 | 112.54 (11) | C19—C27—C26 | 115.96 (13) |
N9—C10—H10B | 109.1 | C19—C27—H27 | 122 |
C11—C10—H10B | 109.1 | C26—C27—H27 | 122 |
N9—C10—H10A | 109.1 | O18—C19—C27 | 125.35 (12) |
C11—C10—H10A | 109.1 | O18—C19—C20 | 110.50 (11) |
H10B—C10—H10A | 107.8 | C27—C19—C20 | 124.15 (12) |
N7—C8—N9 | 114.90 (13) | C4—N9—C8 | 105.52 (11) |
N7—C8—H8 | 122.6 | C4—N9—C10 | 127.12 (12) |
N9—C8—H8 | 122.6 | C8—N9—C10 | 127.32 (12) |
N7—C5—C4 | 110.43 (12) | C8—N7—C5 | 103.09 (11) |
N7—C5—C6 | 133.55 (12) | C2—N1—C6 | 116.97 (12) |
C4—C5—C6 | 116.02 (12) | C2—N3—C4 | 110.28 (11) |
N1—C6—C5 | 119.02 (12) | C14—O22—C23 | 117.51 (11) |
N1—C6—C17 | 118.07 (12) | C19—O18—C17 | 105.49 (10) |
C5—C6—C17 | 122.90 (12) | ||
O22—C14—C15—C16 | −179.57 (13) | C25—C26—C27—C19 | −0.2 (2) |
C13—C14—C15—C16 | 0.7 (2) | C26—C27—C19—O18 | −179.33 (13) |
C14—C15—C16—C11 | −0.9 (2) | C26—C27—C19—C20 | 0.7 (2) |
C15—C16—C11—C12 | 0.3 (2) | C24—C20—C19—O18 | 179.47 (12) |
C15—C16—C11—C10 | −179.72 (13) | C21—C20—C19—O18 | −0.71 (15) |
C16—C11—C12—C13 | 0.4 (2) | C24—C20—C19—C27 | −0.5 (2) |
C10—C11—C12—C13 | −179.60 (13) | C21—C20—C19—C27 | 179.31 (13) |
C11—C12—C13—C14 | −0.5 (2) | N3—C4—N9—C8 | 179.55 (13) |
O22—C14—C13—C12 | −179.79 (13) | C5—C4—N9—C8 | −0.27 (14) |
C15—C14—C13—C12 | −0.1 (2) | N3—C4—N9—C10 | 1.8 (2) |
C16—C11—C10—N9 | 84.43 (16) | C5—C4—N9—C10 | −178.07 (12) |
C12—C11—C10—N9 | −95.59 (16) | N7—C8—N9—C4 | 0.36 (16) |
N7—C5—C6—N1 | 178.71 (13) | N7—C8—N9—C10 | 178.16 (12) |
C4—C5—C6—N1 | −1.07 (18) | C11—C10—N9—C4 | 79.64 (17) |
N7—C5—C6—C17 | −0.1 (2) | C11—C10—N9—C8 | −97.70 (16) |
C4—C5—C6—C17 | −179.86 (12) | N9—C8—N7—C5 | −0.28 (16) |
N7—C5—C4—N3 | −179.71 (12) | C4—C5—N7—C8 | 0.10 (15) |
C6—C5—C4—N3 | 0.1 (2) | C6—C5—N7—C8 | −179.70 (14) |
N7—C5—C4—N9 | 0.11 (15) | N3—C2—N1—C6 | 1.5 (2) |
C6—C5—C4—N9 | 179.95 (11) | Cl2—C2—N1—C6 | −177.23 (9) |
N1—C6—C17—C21 | −174.32 (14) | C5—C6—N1—C2 | 0.43 (18) |
C5—C6—C17—C21 | 4.5 (2) | C17—C6—N1—C2 | 179.28 (12) |
N1—C6—C17—O18 | 4.85 (17) | N1—C2—N3—C4 | −2.3 (2) |
C5—C6—C17—O18 | −176.35 (11) | Cl2—C2—N3—C4 | 176.42 (9) |
O18—C17—C21—C20 | −0.57 (15) | N9—C4—N3—C2 | −178.44 (13) |
C6—C17—C21—C20 | 178.64 (13) | C5—C4—N3—C2 | 1.34 (19) |
C17—C21—C20—C19 | 0.76 (15) | C13—C14—O22—C23 | −168.83 (13) |
C17—C21—C20—C24 | −179.47 (15) | C15—C14—O22—C23 | 11.5 (2) |
C19—C20—C24—C25 | −0.12 (19) | C27—C19—O18—C17 | −179.64 (13) |
C21—C20—C24—C25 | −179.87 (14) | C20—C19—O18—C17 | 0.38 (14) |
C20—C24—C25—C26 | 0.6 (2) | C21—C17—O18—C19 | 0.13 (14) |
C24—C25—C26—C27 | −0.4 (2) | C6—C17—O18—C19 | −179.20 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
C26—H26···Cg1i | 0.95 | 2.85 | 3.6453 (18) | 141 |
C8—H8···O18ii | 0.95 | 2.66 | 3.6034 (17) | 172 |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x−1, y, z−1. |
Experimental details
Crystal data | |
Chemical formula | C21H15ClN4O2 |
Mr | 390.82 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 112 |
a, b, c (Å) | 8.0721 (8), 28.668 (3), 8.3764 (9) |
β (°) | 114.876 (2) |
V (Å3) | 1758.6 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.24 |
Crystal size (mm) | 0.3 × 0.2 × 0.2 |
Data collection | |
Diffractometer | Siemens SMART CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.642, 0.952 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16890, 4334, 3366 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.685 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.094, 1.03 |
No. of reflections | 4334 |
No. of parameters | 255 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.31, −0.23 |
Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Version 1.08; Farrugia, 1997) and POV-RAY for Windows (Persistence of Vision Pty Ltd, 2004), SHELXL97 and WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
C26—H26···Cg1i | 0.95 | 2.85 | 3.6453 (18) | 141 |
C8—H8···O18ii | 0.95 | 2.66 | 3.6034 (17) | 172 |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x−1, y, z−1. |
Compound (I) | Molecule A in (II)a | Molecule B in (II)a | |
C6—C17 | 1.4521 (18) | 1.4479 (15) | 1.4497 (15) |
C10—N9 | 1.4732 (17) | 1.4755 (15) | 1.4740 (15) |
C10—C11 | 1.5122 (19) | 1.5128 (16) | 1.5127 (16) |
C14—O22—C23 | 117.51 (11) | 118.12 (10) | 116.93 (9) |
C15—C14—O22—C23 | 11.5 (2) | 11.24 (17) | -2.45 (17) |
C4—N9—C10—C11 | 79.64 (17) | 78.72 (15) | -70.99 (15) |
N9—C10—C11—C12 | -95.59 (16) | -94.59 (14) | 91.21 (13) |
Notes: (a) Braendvang & Gundersen (2007a). |
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We have discovered that certain 6-aryl-9-benzylpurines are potent antimycobacterials in vitro and may have a potensial as antitubercular drugs (Bakkestuen et al., 2000; Gundersen et al., 2002; Bakkestuen et al., 2005; Braendvang & Gundersen, 2005). The title compound, (I), was synthesized as a close analog of the previously reported antimycobacterial 2-chloro-6-(2-furanyl)-9-[(4-methoxyphenyl)methyl]-9H-purine, (II), (Bakkestuen et al., 2005).
The molecular geometries is illustrated in Fig. 1. The selected bond lenghts and angles are listed in Table 1 and compared with the recently reported X-ray structure of compound (II) (Braendvang & Gundersen, 2007a). There are only small differences in bond lenghts and angles in these two compounds, specially molecule A in compound (II) resembles the title compound (I) (Table 1). In compound (I) the angle between the mean plane of the purine ring system and the furyl ring C17/O18/C19—C21 is 4.49 (7)°, or 4.82 (5)° if the mean plane of benzofuryl is used. In compound (II) the angles were 2.31 (6)° in molecule A and 2.79 (5)° in molecule B.
The positions of the benzyl groups are only slightly different in compound (I) and (II) as seen from the torsion angles C4—N9—C10—C11 and N9—C10—C11—C12 (Table 1). The benzene ring C11—C16 is inclined at an angle of 70.68 (6)° to the purine ring in compound (I). Previously reported for compound (II) is 73.64 (5)° in molecule A and 77.80 (4)° in molecule B.
Fig. 2 shows the crystal packing of (I) in the unit cell. The conformation adopted by the benzene rings allows for simultaneous C—H···π interactions, and π–π interactions to form dimers of molecules (Fig. 3). The C—H···π interactions occurs between the C26—H26···Cg1i (Table 2) (Cg1 is the centroid of the benzene ring C11—C16) [symmetry code: (i) 2 - x, 1 - y, 1 - z]. In these dimers, π–π interactions occurs between the purine ring system and the benzene ring C19/C20/C24—C27 in the benzofuryl group. In this interaction the benzene ring C19/C20/C24—C27 and the pyrimidine ring N1/C2/N3/C4—C6 are slipped by 18.7 ° relative to their ring perpendiculars (the average interplanar distance between the benzene ring in the benzofuryl group and the pyrimidine ring N1/C2/N3/C4—C6 is 3.339 Å), the ring-centroid to ring-centroid distance being 3.5277 (10) Å. The average interplanar distance between the benzene ring in the benzofuryl group and the imidazole ring C4/C5/N7/C8/N9 is 3.424 Å (the two rings are slipped by 22.8° relative to their ring perpendiculars), the ring-centroid to ring-centroid distance being 3.7161 (10) Å.
The crystal packing (Fig. 2) gives further π–π interactions between the imidazole ring (C4A—N9A) and the furyl ring C17/O18/C19—C21iii, the ring-centroid to centroid distance is 3.5084 (10) Å [symmetry code: (iii) 1 - x, 1 - y, 1 - z]. In this interaction the average interplanar distance is 3.318 Å and the two rings are slipped by 19.0° relative to their ring perpendiculars.
Finally, the orientation of the furyl group in compound (I) is stabilized by weak C8—H8···O18ii hydrogen bonding, forming infinite chains of molecules (Table 2 and Fig. 3) [symmetry code: (ii) x - 1, y, z - 1].
The molecular packing of compound (I) in overall is very similar to the previous reported (II) (Braendvang & Gundersen, 2007a).