Diisopropyl {[(R)-2-(2-amino-6-chloro-9H-purin-9-yl)-1-methyl­eth­oxy]meth­yl}­phospho­nate

Guobao Zhao; Xinhua He; Bohua Zhong

doi:10.1107/S1600536812006757

. 2012 Mar 3;68(Pt 4):o936. doi: 10.1107/S1600536812006757

Diisopropyl {[(R)-2-(2-amino-6-chloro-9H-purin-9-yl)-1-methylethoxy]methyl}phosphonate

Guobao Zhao ^a, Xinhua He ^a,^*, Bohua Zhong ^a

PMCID: PMC3343918 PMID: 22589999

Abstract

In the title compound, C₁₅H₂₅ClN₅O₄P, the r.m.s. deviation for the purine ring system is 0.0165 Å. The coordination about the P atom is a distorted tetrahedron [O=P—O angles = 116.70 (6) and 109.87 (6)°]. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, generating a three-dimensional network.

Related literature

For details of the synthesis, see: Yu et al. (1992 ▶). For the bioactivity of nucleoside analogues, see: Martin (1989 ▶). For reference bond lengths, see: Allen et al. (1987 ▶). For a related structure, see: Baszczyňski et al. (2011 ▶).

Experimental

Crystal data

C₁₅H₂₅ClN₅O₄P
M _r = 405.82
Orthorhombic,
a = 7.7991 (12) Å
b = 13.950 (2) Å
c = 18.053 (3) Å
V = 1964.0 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 113 K
0.22 × 0.20 × 0.18 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.936, T _max = 0.947
24716 measured reflections
4669 independent reflections
4468 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.028
wR(F ²) = 0.066
S = 1.05
4669 reflections
240 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.31 e Å⁻³
Absolute structure: Flack (1983 ▶), 2007 Friedel pairs
Flack parameter: 0.02 (4)

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: CrystalStructure (Rigaku, 2005 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812006757/fk2051sup1.cif

e-68-0o936-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812006757/fk2051Isup2.hkl

e-68-0o936-Isup2.hkl^{(228.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812006757/fk2051Isup3.cml

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
N5—H5A⋯O2ⁱ	0.89	2.13	3.0185 (16)	174
N5—H5B⋯O2ⁱⁱ	0.89	2.21	3.0920 (16)	172

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

supplementary crystallographic information

Comment

Nucleoside analogues are in the lead in research and application of the anti-HBV drugs. In our recent work, the title compound (I), Fig. 1, was synthetized according to Kuo-Long Yu et al. (1992). As known, the molecular conformation in single-crystal is low energy conformation, and is helpful to quantitative structure-activity relationship (QSAR) study, therefore this structure determination was undertaken. Though the molecular structure of OSOWUP (Baszczyňski et al., 2011) is similar to the title molecule, the molecular conformation is different (comparison is shown in Fig 3).

In (I), all bonds lengths and angles are normal (Allen et al., 1987). Molecules are stacked along the a axis, and linked into a zigzag sheet propagating along the c axis by intermolecular N—H···O hydrogen bonds (Figure 2 and Table 2).

Experimental

The title compound was synthesized according to the procedure of Kuo-Long Yu et al. (1992). Colourless single crystals (m.p. 404–406 K) were obtained by slow evaporation of a solution in absolute ethanol.