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

Mohamed Tebaa; Noureddine Mazoir; Celia M Maya; Bouhmaida Nouzha; Ahmed Benharref; Moha Berraho

doi:10.1107/S1600536809000191

. 2009 Jan 10;65(Pt 2):o267–o268. doi: 10.1107/S1600536809000191

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

Mohamed Tebaa ^a, Noureddine Mazoir ^a, Celia M Maya ^b, Bouhmaida Nouzha ^c, Ahmed Benharref ^d, Moha Berraho ^a,^*

PMCID: PMC2968392 PMID: 21581882

Abstract

The title heterocyclic compound, C₁₇H₂₃N₃O₂S, was synthesized from 4-(4-methylcyclohex-3-enyl)pent-3-en-2-one, which was isolated from Cedrus atlantica essential oil. The thiadiazole ring adopts a flattened envelope conformation, with the flap sp ³-hybridized C atom lying 0.259 (1) Å out of the plane of the other four atoms. The screw-related molecules are linked into chains along the b axis by intermolecular N—H⋯O hydrogen bonds.

Related literature

For 1,3,4-thiadiazole derivatives and their biological activity, see: Beatriz et al. (2002 ▶); Loughzail et al. (2009 ▶); Mazoir et al. (2008 ▶); Mohammed et al. (2008 ▶); Nakagawa et al. (1996 ▶); Sakthivel et al. (2008 ▶); Tehranchian et al. (2005 ▶); Wang et al. (1999 ▶, 2004 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₇H₂₃N₃O₂S
M _r = 333.44
Monoclinic,
a = 9.3984 (2) Å
b = 11.0510 (2) Å
c = 16.6045 (3) Å
β = 90.442 (10)°
V = 1724.52 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 298 (2) K
0.5 × 0.4 × 0.3 mm

Data collection

Bruker X8 APEX CCD area-detector diffractometer
Absorption correction: none
52162 measured reflections
8286 independent reflections
7182 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.108
S = 1.03
8286 reflections
221 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-Plus (Bruker, 2005 ▶); data reduction: SAINT-Plus; 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 PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809000191/ci2746sup1.cif

e-65-0o267-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809000191/ci2746Isup2.hkl

e-65-0o267-Isup2.hkl^{(397.2KB, 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—H4⋯O2ⁱ	0.89 (1)	1.96 (1)	2.8391 (7)	169 (1)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Professor J. C. Daran for fruitful discussions.

supplementary crystallographic information

Comment

1,3,4-Thiadiazole derivatives (Sakthivel et al., 2008) represent an interesting class of compounds possessing diverses activities: biological (Nakagawa et al., 1996), fungicidal (Wang et al., 1999, 2004) and bactericidal properties (Tehranchian et al., 2005). The work of our research group focused on the phytochemical study of Moroccan plants and aimed to find out new compounds, which could be used as precursors or intermediates for the synthesis of high added value specimens (Mazoir et al., 2008; Loughzail et al.,2009). In this way, we have investigated native Cedrus species rich on sesquiterpene derivatives. Thus a new compound was obtained through chemical modification of 4-(4-methylcyclohex-3-enyl)pent-3-en-2-one, which was isolated from Cedrus Atlantica essential oil. The aromatization of the above compound followed by condensation with thiosemicarbazide (Beatriz et al., 2002; Mohammed et al., 2008) ending with treatment of acetic anhydride in the presence of pyridine yielded a diasterioisomers in high stereoselectivity.

The molecular structure of the title compound is shown in Fig. 1. The thiadiazole ring adopts a flattened envelop conformation as indicated by Cremer & Pople (1975) puckering parameters Q = 0.1578 (6) Å and φ = 148.3 (2)°. Atom C5 deviates from the mean plane through other four atoms in the ring by 0.259 (1) Å.

In the crystal structure, molecules are linked into chains (Fig. 2) running along the b axis by intermolecular N—H···O hydrogen bonds (Table 1) involving the carbonyl and the acetamide groups.

Experimental

A solution of 4-(4-methylcyclohex-3-enyl)pent-3-en-2-one (0.5 g, 2.8 mmol) and Pd/C (10%) was heated at 423 K for 12 h. The product obtained was treated with equimolecular quantity of thiosemicarbazide and several drops of HCl (cc) were added. The reaction mixture was heated at reflux in ethanol for 6 h and then evaporated under reduced pressure and the residue obtained was purified on silica gel column using hexane-ethyl acetate (96:4) as an eluent. 0.25 mmol of the thiosemicarbazone obtained was dissolved in 3 ml of pyridine and 3 ml of acetic anhydride. The mixture was heated on a water bath for 1.5 h. The resulting residue was concentrated in vacuo and chromatographied on silica gel column with hexane-ethyl acetate (92:8) as an eluent. Suitable crystals were obtained by evaporation of ethyl acetate solution at 277 K.