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

Michal Rouchal; Marek Nečas; Robert Vícha

doi:10.1107/S1600536810011797

. 2010 Apr 2;66(Pt 5):o1016. doi: 10.1107/S1600536810011797

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

Michal Rouchal ^a, Marek Nečas ^b, Robert Vícha ^a,^*

PMCID: PMC2979083 PMID: 21579080

Abstract

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.

Related literature

The title compound was prepared according to a modification of the 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 ▶).

Experimental

Crystal data

C₁₀H₁₄ClN₅
M _r = 239.71
Monoclinic,
a = 12.0483 (3) Å
b = 8.7689 (2) Å
c = 11.5538 (3) Å
β = 109.965 (3)°
V = 1147.30 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 120 K
0.40 × 0.40 × 0.30 mm

Data collection

Oxford Diffraction Xcalibur (Sapphire2 large Be window) diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T _min = 0.968, T _max = 1.000
13393 measured reflections
2022 independent reflections
1798 reflections with I > 2σ(I)
R _int = 0.016

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.068
S = 1.05
2022 reflections
149 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; 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.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810011797/pk2238sup1.cif

e-66-o1016-sup1.cif^{(15.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810011797/pk2238Isup2.hkl

e-66-o1016-Isup2.hkl^{(99.5KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4A⋯N1ⁱ	0.95	2.49	3.3728 (18)	154
C7—H7C⋯Cl1ⁱⁱ	0.98	2.91	3.5981 (14)	128
C7—H7B⋯N3ⁱⁱⁱ	0.98	2.75	3.584 (2)	143
C9—H9A⋯N3^iv	0.98	2.73	3.6664 (18)	161

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

The financial support of this work by the Czech Ministry of Education, project No. MSM 7088352101 is gratefully acknowledged.

supplementary crystallographic information

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).

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.