Dimethyl [(4-fluoro­phen­yl)(6-methoxy­benzothia­zol-2-ylamino)meth­yl]phospho­nate

Yan-Ping Hong; Bao-An Song; Xin-Chen Shangguan

doi:10.1107/S1600536809015384

. 2009 May 7;65(Pt 6):o1199–o1200. doi: 10.1107/S1600536809015384

Dimethyl [(4-fluorophenyl)(6-methoxybenzothiazol-2-ylamino)methyl]phosphonate

Yan-Ping Hong ^a,^b,^*, Bao-An Song ^b, Xin-Chen Shangguan ^a

PMCID: PMC2969702 PMID: 21583070

Abstract

In the molecule of title compound, C₁₇H₁₈FN₂O₄PS, both the benzene ring with its conjunction C atom and the benzothiazole ring with its conjunction N atom are close to planar (the maximum deviations are 0.0267 and 0.0427 Å for the benzene and benzothiazole rings, respectively), the dihedral angle between the planes of the benzothiazole and benzene rings is 119.05 (3)°. The molecular packing is stabilized by intermolecular N—H⋯O, C—H⋯N and C—H⋯F hydrogen bonding, and by C—H⋯π and π–π stacking interactions [centroid–centroid distances = 2.99 (2), 2.96 (3), 2.88 (2) and 3.773 (4) Å].

Related literature

For the biological activity of α-aminophosphonate derivatives, see: Kafarski & Lejczak (2001 ▶); De Lombaert et al. (1995 ▶); Du et al., (1999 ▶). For activities of α-aminophosphonate derivatives containing an F atom and benzothiazole or iaoxazole units, see: Yang et al. (2005 ▶); Song et al. (2005 ▶); Jin et al. (2006 ▶). For related structures, see: Fang et al. (2009 ▶); Yang et al. (2005 ▶); Jin et al. (2006 ▶); Song et al. (2005 ▶); Alvarez et al. (2005 ▶); Chen & Li (1987 ▶); Li et al. (2008 ▶).

Experimental

Crystal data

C₁₇H₁₈FN₂O₄PS
M _r = 396.36
Monoclinic,
a = 19.761 (5) Å
b = 15.781 (4) Å
c = 14.395 (4) Å
β = 122.109 (3)°
V = 3802.4 (16) Å³
Z = 8
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 296 K
0.30 × 0.26 × 0.22 mm

Data collection

Bruker APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.919, T _max = 0.939
9669 measured reflections
3428 independent reflections
2477 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.115
S = 1.04
3428 reflections
238 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; 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: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809015384/at2769sup1.cif

e-65-o1199-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809015384/at2769Isup2.hkl

e-65-o1199-Isup2.hkl^{(168.2KB, 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
N1—H1⋯O2ⁱ	0.86	1.99	2.793 (3)	156
C16—H16C⋯F1ⁱⁱ	0.96	2.51	3.2496	133
C15—H15B⋯Cg1ⁱⁱⁱ	0.96	2.99	3.608 (4)	123
C16—H16B⋯Cg3^iv	0.96	2.96	3.549 (4)	121
C17—H17C⋯Cg1^v	0.96	2.88	3.625 (3)	136

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) . Cg1 and Cg3 are the centroids of the S1/N2/C4–C6 and C9–C14 rings, respectively.

Acknowledgments

The authors acknowledge Jiangxi Agricultural University for supporting this work.

supplementary crystallographic information

Comment

α-Aminophosphonate derivatives, as isosteres of natural aminocarboxylic acids, have attracted much attention in medicinal and pesticide chemistry in recent years due to their wide range of biological activities (Kafarski et al., 2001; De Lombaert et al., 1995; Du et al., 1999). In our previous work, a plenty of α-aminophosphonate derivatives containing fluorine atom and benzothiazole or iaoxazole moieties had been synthesized and some of them showed fungicidal (Yang et al.,2005) and antitumor activities (Song et al., 2005; Jin et al., 2006). And some crystals of α-aminophosphonate derivatives containing dialkyl had been reported in our previous works. However, It is noteworthy that a cystal of α-aminophosphonate containing dimethyl moiety was obtained for the first time. We report herein the crystal structure of the title compound.

As illustrated in Fig. 1, both the benzene ring with its conjunction carbon atom C8 and the benzothiazole ring with its conjunction nitrogen atom N1 are fairly planar, the dihedral angle between the planes of the benzothiazole group (C1–C7/N2/S1) and the benzene ring (C9–C14) is 119.05 °. The P atom exhibits a distorted tetrahedral configuration because the bond angles of O2—P1—O3 = 116.07 (11) ° and O2—P1—O4 = 114.04 (10) ° are significantly larger than that of O3—P1—O4 = 103.65 (10) °. The P1—C8 = 1.807 (2) Å is similar to the corresponding P—C value of 1.809 (3) Å found in diisopropyl [(benzoylamino)(phenyl)methyl] phosphonate (Fang et al., 2009) and a little shorter than normal P—C single bond length of 1.850 Å (Chen et al., 1987). The C5—N1 = 1.355 (3) Å is remarkably shorter than normal C—N 1.471 (3) Å (Alvarez et al., 2005) and close to the C = N = 1.343 (2) Å, similar to the corresponding bond length of 1.358 (3) Å of the 2-(1-piperidinyl)-1,3-benzothiazole (Alvarez et al., 2005). Meanwhile, the S1—C6 and S1—C5 with bond lengths of 1.742 (2) Å and 1.760 (2) Å, respectively, are shorter than the typical C—S of 1.811 (9) Å (Li et al., 2008). These indicate that the N1 atom and benzothiazole ring form a considerable delocalization of the electron density in which the N1 atom is sp² hybridized. The molecular packing is consolidated through weak inter/intra molecular N—H···O, C—H···N, and C—H···F hydrogen bonding, C—H···π and π-π stacking interactions (Table 2, Fig. 2, Cg1 = ring (S1/N2/C4—C6); Cg3 = ring(C9–C14)). C—H···π interactions of methyl H atoms are established towards the π-systems of neighboring aromatic groups from 4-fluorophenyl and five rings of 6-methoxybenzothiazol-2-ylamino, with centroid-to-centroid distance are 2.99 (2), 2.96 (3) and 2.88 (2) Å, respectively. In the π-π stacking interactions between two close-by phenyl rings of 4-fluorophenyl, tThe centroid-to-centroid distance is 3.773 (4) Å.

Experimental

A mixture of 2-amino-6-methoxylbenzothiazole (0.9010 g, 5 mmol) and 4-fluorobenzaldehyde (0.6205 g, 5 mmol) and 20 ml toluene in a 50 ml dry flask affiliated a water separator was refluxed and stirred for 6 h. Toluene was removed by water separator and then dimethylphosphate (0.88 g, 8 mmol) was added into the flask, the reaction mixture was refluxed in a nonsolvent condition for 5 h. Residue was washed with water, filtered, dried, and crystallized three times from ethanol yielding title compound as colorless solid. The crystal suitable for X-ray analysis was obtained by slow evaporation of an anhydrous ethanol at room temperature over a period of ten days.