2-Chloro-9-isopropyl-N,N-dimethyl-9H-purin-6-amine

In the title compound, C₁₀H₁₄ClN₅, the imidazole and pyrimidine rings are essentially planar [maximum deviation = 0.0013 (14) and 0.0207 (13) Å, respectively]. In the crystal, the mol­ecules are linked by weak C—H...N inter­actions into chains parallel to the c axis and the crystal packing is stabilized by additional weak C—H...N and C—H...Cl inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.025
• wR factor = 0.068
• Data-to-parameter ratio = 13.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT480_ALERT_4_C Long H...A H-Bond Reported H7C    ..  CL1     ..       2.91 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H7B    ..  N3      ..       2.75 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9A    ..  N3      ..       2.73 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 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
   1 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The heterocyclic system, imidazo[4,5-d]pyrimidine, commonly known as purine, was first named by Emil Fisher at the turn of the 19^th century. A large number of variously substituted purines exhibit a wide range of biological activities (Legraverend & Grierson, 2006). They act as interferon inducers, adenosine receptor ligands, inhibitors of microtubule assembly, protein kinases, sulfotransferases and phosphodiesterases. The title molecule was prepared as a part of our research into the synthesis of novel trisubstituted purines.

The asymmetric unit of the title compound consists of a single purine molecule. Both imidazole and pyrimidine rings are nearly planar with maximum deviations from the mean plane being 0.0013 (14) Å for C4 (imidazole ring) and 0.0207 (13) Å for C2 (pyrimidine ring). Both carbon atoms of the dimethylamino substituent lie essentially in the pyrimidine mean plane as demonstrated by torsion angles C3—C2—N5—C7 and C3—C2—N5—C6, which are 4.3 (2)° and 175.90 (13)°, respectively. The torsion angle describing the orientation of isopropyl and purine ring, H8A—C8—N4—C4 is -163.55 (13)°. Molecules are linked into chains along the c axis by weak C4—H4···N1 interactions (Table 1, Fig. 2). Crystal packing is further stabilised by short C—H···N and C—H···Cl contacts (Table 1).

Related literature

The title compound was prepared according to a modified procedure of Fiorini & Abel (1998). For the synthesis and/or biological activity of related compounds, see: Legraverend & Grierson (2006). For related structures, see: Kubicki & Codding (2001); Trávníček & Popa (2007); Rouchal et al. (2009a,b,c).

S2. Experimental

The title compound was prepared according to a slightly modified literature procedure (Fiorini & Abel, 1998). 2,6-Dichloro-9-(propan-2-yl)-9H-purine (0.87 mmol, 196 mg) and methylamine hydrochloride (0.91 mmol, 61.5 mg) were dissolved in a mixture of DMF (2.5 ml) and N-ethyl-N-isopropylpropan-2-amine (1.74 mmol, 225 mg). The resulting solution was stirred at 90 °C for 2 hours. Subsequently, the mixture was diluted with water and extracted with diethyl ether. Combined organic layers were washed twice with brine and dried over Na₂SO₄. Crude product consisting of two compounds with relative abundances of 43% and 57% according to GC were obtained after evaporation of the solvent in vacuum. The products were identified as N-methyl and N,N-dimethyl derivatives. Column chromatography (silica gel; petroleum ether/ethyl acetate, v/v, 1/1) yielded the latter as a colourless crystalline powder (105 mg, 54%, mp 418–422 K). The crystal used for data collection was grown by spontaneous evaporation from deuterochloroform at room temperature.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. An ellipsoid plot (50% probability) of the asymmetric unit. Hydrogen atoms are represented as arbitrary spheres.
	Fig. 2. A view of the crystal structure showing chains parallel to the a-axis linked via C—H···N contacts (dotted lines). H-atoms (except those which are involved in H-bonding) have been omitted for clarity.

2-Chloro-9-isopropyl-N,N-dimethyl-9H-purin-6-amine

Crystal data

C10H14ClN5	F(000) = 504
Mr = 239.71	Dx = 1.388 Mg m^−3
Monoclinic, P21/c	Melting point = 422–418 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.7107 Å
a = 12.0483 (3) Å	Cell parameters from 8720 reflections
b = 8.7689 (2) Å	θ = 2.9–27.3°
c = 11.5538 (3) Å	µ = 0.31 mm^−1
β = 109.965 (3)°	T = 120 K
V = 1147.30 (5) Å^3	Block, colourless
Z = 4	0.40 × 0.40 × 0.30 mm

Data collection

Oxford Diffraction Xcalibur (Sapphire2 large Be window) diffractometer	2022 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1798 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
Detector resolution: 8.4 pixels mm^-1	θmax = 25.0°, θmin = 2.9°
ω scans	h = −14→13
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009)	k = −9→10
Tmin = 0.968, Tmax = 1.000	l = −13→13
13393 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.068	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0355P)^2 + 0.4207P] where P = (Fo^2 + 2Fc^2)/3
2022 reflections	(Δ/σ)max < 0.001
149 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

Special details

Experimental. CrysAlis RED (Oxford Diffraction Ltd, 2009). Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Cl1	0.78721 (3)	0.18146 (4)	0.33908 (3)	0.02432 (12)
N1	0.80758 (9)	−0.04481 (12)	0.48883 (9)	0.0166 (2)
N2	0.67313 (9)	0.15775 (12)	0.49228 (10)	0.0179 (3)
N3	0.69089 (10)	−0.14494 (13)	0.72589 (10)	0.0225 (3)
N4	0.82037 (10)	−0.23853 (13)	0.64258 (10)	0.0184 (3)
N5	0.55582 (10)	0.16106 (13)	0.61327 (10)	0.0197 (3)
C1	0.75175 (11)	0.08580 (15)	0.45552 (11)	0.0168 (3)
C2	0.63956 (11)	0.09009 (15)	0.58130 (11)	0.0169 (3)
C3	0.69562 (11)	−0.04950 (15)	0.63134 (11)	0.0167 (3)
C4	0.76612 (12)	−0.25408 (16)	0.72857 (13)	0.0229 (3)
H4A	0.7816	−0.3366	0.7851	0.027*
C5	0.77572 (11)	−0.10713 (15)	0.57988 (11)	0.0157 (3)
C6	0.51096 (13)	0.30962 (16)	0.56040 (14)	0.0256 (3)
H6A	0.4933	0.3068	0.4711	0.038*
H6B	0.5707	0.3880	0.5968	0.038*
H6C	0.4388	0.3337	0.5778	0.038*
C7	0.51768 (12)	0.10497 (17)	0.71274 (13)	0.0248 (3)
H7A	0.5191	−0.0068	0.7134	0.037*
H7B	0.4372	0.1406	0.6998	0.037*
H7C	0.5711	0.1435	0.7917	0.037*
C8	0.90697 (12)	−0.34193 (16)	0.61883 (13)	0.0214 (3)
H8A	0.9468	−0.2849	0.5691	0.026*
C9	0.84438 (14)	−0.47859 (18)	0.54375 (14)	0.0314 (4)
H9A	0.7866	−0.4433	0.4660	0.047*
H9B	0.8038	−0.5358	0.5904	0.047*
H9C	0.9024	−0.5447	0.5265	0.047*
C10	1.00104 (13)	−0.38877 (18)	0.73954 (14)	0.0294 (3)
H10A	1.0359	−0.2974	0.7868	0.044*
H10B	1.0627	−0.4476	0.7221	0.044*
H10C	0.9650	−0.4515	0.7874	0.044*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0311 (2)	0.0225 (2)	0.02385 (19)	0.00422 (14)	0.01520 (15)	0.00769 (13)
N1	0.0180 (5)	0.0170 (6)	0.0149 (5)	−0.0002 (4)	0.0058 (4)	0.0005 (4)
N2	0.0189 (6)	0.0173 (6)	0.0176 (5)	0.0002 (4)	0.0062 (4)	−0.0005 (4)
N3	0.0256 (6)	0.0227 (6)	0.0219 (6)	0.0007 (5)	0.0115 (5)	0.0038 (5)
N4	0.0198 (6)	0.0168 (6)	0.0189 (6)	0.0020 (4)	0.0071 (5)	0.0037 (5)
N5	0.0196 (6)	0.0200 (6)	0.0204 (6)	0.0021 (5)	0.0081 (5)	−0.0020 (5)
C1	0.0192 (7)	0.0170 (7)	0.0136 (6)	−0.0023 (5)	0.0046 (5)	−0.0003 (5)
C2	0.0162 (6)	0.0174 (7)	0.0152 (6)	−0.0031 (5)	0.0031 (5)	−0.0048 (5)
C3	0.0169 (6)	0.0174 (7)	0.0155 (6)	−0.0025 (5)	0.0049 (5)	−0.0019 (5)
C4	0.0267 (7)	0.0221 (8)	0.0219 (7)	0.0014 (6)	0.0109 (6)	0.0067 (6)
C5	0.0149 (6)	0.0153 (7)	0.0149 (6)	−0.0017 (5)	0.0025 (5)	−0.0016 (5)
C6	0.0264 (7)	0.0228 (8)	0.0280 (8)	0.0070 (6)	0.0097 (6)	−0.0013 (6)
C7	0.0231 (7)	0.0284 (8)	0.0276 (7)	−0.0006 (6)	0.0148 (6)	−0.0038 (6)
C8	0.0202 (7)	0.0212 (7)	0.0250 (7)	0.0051 (6)	0.0105 (6)	0.0055 (6)
C9	0.0347 (9)	0.0262 (8)	0.0329 (8)	0.0061 (7)	0.0110 (7)	−0.0036 (7)
C10	0.0225 (7)	0.0306 (8)	0.0326 (8)	0.0044 (6)	0.0064 (6)	0.0094 (7)

Geometric parameters (Å, º)

Cl1—C1	1.7575 (13)	C6—H6A	0.9800
N1—C1	1.3174 (17)	C6—H6B	0.9800
N1—C5	1.3522 (17)	C6—H6C	0.9800
N2—C1	1.3230 (17)	C7—H7A	0.9800
N2—C2	1.3630 (17)	C7—H7B	0.9800
N3—C4	1.3112 (18)	C7—H7C	0.9800
N3—C3	1.3926 (17)	C8—C9	1.520 (2)
N4—C5	1.3696 (17)	C8—C10	1.5228 (19)
N4—C4	1.3698 (18)	C8—H8A	1.0000
N4—C8	1.4769 (17)	C9—H9A	0.9800
N5—C2	1.3402 (17)	C9—H9B	0.9800
N5—C7	1.4610 (18)	C9—H9C	0.9800
N5—C6	1.4618 (18)	C10—H10A	0.9800
C2—C3	1.4220 (19)	C10—H10B	0.9800
C3—C5	1.3900 (18)	C10—H10C	0.9800
C4—H4A	0.9500
C1—N1—C5	109.04 (11)	N5—C6—H6C	109.5
C1—N2—C2	117.66 (11)	H6A—C6—H6C	109.5
C4—N3—C3	104.13 (11)	H6B—C6—H6C	109.5
C5—N4—C4	105.59 (11)	N5—C7—H7A	109.5
C5—N4—C8	126.37 (11)	N5—C7—H7B	109.5
C4—N4—C8	128.02 (11)	H7A—C7—H7B	109.5
C2—N5—C7	121.94 (11)	N5—C7—H7C	109.5
C2—N5—C6	120.29 (11)	H7A—C7—H7C	109.5
C7—N5—C6	117.26 (11)	H7B—C7—H7C	109.5
N1—C1—N2	132.14 (12)	N4—C8—C9	110.23 (11)
N1—C1—Cl1	113.90 (10)	N4—C8—C10	110.34 (11)
N2—C1—Cl1	113.95 (10)	C9—C8—C10	112.28 (12)
N5—C2—N2	116.82 (12)	N4—C8—H8A	107.9
N5—C2—C3	125.83 (12)	C9—C8—H8A	107.9
N2—C2—C3	117.35 (11)	C10—C8—H8A	107.9
C5—C3—N3	109.72 (11)	C8—C9—H9A	109.5
C5—C3—C2	116.22 (12)	C8—C9—H9B	109.5
N3—C3—C2	134.05 (12)	H9A—C9—H9B	109.5
N3—C4—N4	114.04 (12)	C8—C9—H9C	109.5
N3—C4—H4A	123.0	H9A—C9—H9C	109.5
N4—C4—H4A	123.0	H9B—C9—H9C	109.5
N1—C5—N4	125.94 (12)	C8—C10—H10A	109.5
N1—C5—C3	127.51 (12)	C8—C10—H10B	109.5
N4—C5—C3	106.52 (11)	H10A—C10—H10B	109.5
N5—C6—H6A	109.5	C8—C10—H10C	109.5
N5—C6—H6B	109.5	H10A—C10—H10C	109.5
H6A—C6—H6B	109.5	H10B—C10—H10C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4A···N1^i	0.95	2.49	3.3728 (18)	154
C7—H7C···Cl1^ii	0.98	2.91	3.5981 (14)	128
C7—H7B···N3^iii	0.98	2.75	3.584 (2)	143
C9—H9A···N3^iv	0.98	2.73	3.6664 (18)	161

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