N-[4-Acetyl-5-(3-methoxy­phen­yl)-4,5-dihydro-1,3,4-thia­diazol-2-yl]acetamide

G Aridoss; S Amirthaganesan; D Velmurugan; S H Kim; Y T Jeong

doi:10.1107/S1600536808032108

. 2008 Oct 11;64(Pt 11):o2096. doi: 10.1107/S1600536808032108

N-[4-Acetyl-5-(3-methoxyphenyl)-4,5-dihydro-1,3,4-thiadiazol-2-yl]acetamide

G Aridoss ^a, S Amirthaganesan ^a, D Velmurugan ^b, S H Kim ^a, Y T Jeong ^a,^*

PMCID: PMC2959549 PMID: 21580960

Abstract

The title compound, C₁₃H₁₅N₃O₃S, crystallizes with two molecules in the asymmetric unit. The thiadiazole rings in both the molecules adopt an envelope conformation. The crystal packing is stabilized by intermolecular N—H⋯O and C—H⋯O interactions.

Related literature

For biological activities of thiadiazole derivatives, see: Balasubramanian et al. (2004 ▶); Li et al. (2001 ▶); Radwan et al. (2007 ▶); Supuran et al. (2001 ▶). For ring conformational analysis, see: Cremer & Pople (1975 ▶); Nardelli (1983 ▶).

Experimental

Crystal data

C₁₃H₁₅N₃O₃S
M _r = 293.34
Monoclinic,
a = 11.3790 (4) Å
b = 10.5993 (3) Å
c = 11.9596 (2) Å
β = 108.225 (2)°
V = 1370.08 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 293 (2) K
0.30 × 0.20 × 0.16 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ▶) T _min = 0.930, T _max = 0.962
16660 measured reflections
7595 independent reflections
5635 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.109
S = 1.03
7595 reflections
367 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.25 e Å⁻³
Absolute structure: Flack (1983 ▶), with 3584 Friedel pairs
Flack parameter: 0.07 (7)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808032108/bt2802sup1.cif

e-64-o2096-sup1.cif^{(25.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808032108/bt2802Isup2.hkl

e-64-o2096-Isup2.hkl^{(364.1KB, 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
N3—H3A⋯O5ⁱ	0.86	1.95	2.801 (3)	171
N6—H6A⋯O2ⁱⁱ	0.86	1.96	2.799 (3)	164
C25—H25C⋯O2ⁱⁱ	0.96	2.37	3.238 (4)	150

Open in a new tab

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

Acknowledgments

This research work was supported by the second stage of the BK21 Program, Republic of Korea. DV acknowledges financial support from the University Grants Commission (UGC-SAP) and the Department of Science and Technology (DST-FIST), Government of India, for providing facilities.

supplementary crystallographic information

Comment

Nitrogen heterocycles are one of the most important classes of biologically active compounds. Suitably substituted 1,3,4-thiadiazoles have attracted great attention owing to their broad spectrum of biological activities in the areas of medicine which includes antimicrobial, antituberculosis, anesthetic, antithrombotic, anticonvulsant, antihypertensive, anti-inflammatory and antiulcer activities (Balasubramanian et al., 2004; Li et al., 2001; Radwan et al. 2007; Supuran et al., 2001). Their action depends directly on the type and location of polar substituents on the heterocyclic ring. In general, pharmacological effect of potential drugs depends sensitively and solely on the stereochemistry and ring conformations. Thus, by keeping in view the promising biological potency of 1,3,4-thiadiazoles and variously substituted 1,3,4-thiadiazole frameworks, we have carried out the crystal structure determination of the title compound.

The title compound crystallizes with two molecules in the asymmetric unit. The sum of the angles at N1 (359.9 (6)°) and N4 (360.0 (6)°) are in accordance with sp² hybridization. The torsion angles around C6—C1—O1—C13 [0.0 (4)°] and C19—C14—O4—C26 [-1.8 (4)°] indicates the coplanarity of the methoxy groups with the corresponding phenyl rings (C1–C6) and (C14–C19), respectively. The thiadiazole ring in both the molecules adopt envelope conformation with atoms C7 and C20 deviating by 0.395 (3) and 0.350 (3) Å, respectively, from the mean plane of the remaining atoms. The puckering parameters (Cremer & Pople, 1975) and the smallest displacement asymmetry parameters (Nardelli, 1983) for the thiadiazole rings C10—S2—C7—N1—N2 and C20—S2—C23—N5—N4 are q₂ = 0.245 (2), 0.217 (2) Å, φ = 36.4 (6), 215.4 (6)° and Δ_s(C₇) = 6.9 (2), Δ_s(C₂₀) = 5.4 (2), respectively. N—H···O and C—H···O intermolecular interactions stabilize the crystal packing (Table 1).

Experimental

The title compound was obtained by applying the method of Balasubramanian et al. (2004). 3-Methoxybenzadehyde thiosemicarbazone obtained by the reaction of 3-Methoxybenzadehyde and thiosemicarbazide was refluxed with excess of freshly distilled acetic anhydride on a water bath for about 7 h. After the completion of reaction, the excess of acetic anhydride was distilled off under reduced pressure and the obtained crude mass was purified by column chromatography (benzene–ethylacetate 5:1 v/v). Crystals were obtained from the solution of freshly distilled ethanol by slow evaporation at room temperature. ¹H NMR (DMSO-d₆, p.p.m.): 10.90 (s, 1H, amide NH); 7.36–6.76 (m, 5H, aromatic and ring methine protons); 3.78 (s, 3H, OCH₃); 2.38 (s, 3H, –COCH₃); 2.28 (s, 3H, –COCH₃).