Ethyl 4-(3-benzoyl­thio­ureido)benzoate

Sohail Saeed; Moazzam Hussain Bhatti; Uzma Yunus; Peter G Jones

doi:10.1107/S1600536808017856

. 2008 Jul 12;64(Pt 8):o1485. doi: 10.1107/S1600536808017856

Ethyl 4-(3-benzoylthioureido)benzoate

Sohail Saeed ^a,^*, Moazzam Hussain Bhatti ^a, Uzma Yunus ^a, Peter G Jones ^b

PMCID: PMC2962115 PMID: 21203197

Abstract

The title compound, C₁₇H₁₆N₂O₃S, crystallizes in the thioamide form with an intramolecular N—H⋯O hydrogen bond across the thiourea system. Molecules are connected in chains parallel to [10 Inline graphic ] by hydrogen bonds from the second thiourea N—H group to the benzoate C=O function.

Related literature

For related literature, see: Huebner et al. (1953 ▶); Xu et al. (2004 ▶); Xue et al. (2003 ▶); Zeng et al. (2003 ▶); Zheng et al. (2004 ▶); Douglas & Dains (1934 ▶); Glasser & Doughty (1964 ▶); Morales et al. (2000 ▶); D’hooghe et al. (2005 ▶); Dušek (1985 ▶).

Experimental

Crystal data

C₁₇H₁₆N₂O₃S
M _r = 328.38
Monoclinic,
a = 9.6018 (3) Å
b = 8.3882 (3) Å
c = 19.3199 (6) Å
β = 91.393 (4)°
V = 1555.60 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 100 (2) K
0.38 × 0.24 × 0.13 mm

Data collection

Oxford Diffraction Xcalibur S diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▶) T _min = 0.943, T _max = 1.000 (expected range = 0.916–0.971)
31428 measured reflections
5103 independent reflections
3676 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.092
S = 0.94
5103 reflections
217 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: CrysAlis RED (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED; data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP (Siemens, 1994 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808017856/im2071sup1.cif

e-64-o1485-sup1.cif^{(19.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808017856/im2071Isup2.hkl

e-64-o1485-Isup2.hkl^{(249.9KB, 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
N2—H02⋯O1	0.85 (2)	1.89 (2)	2.618 (1)	143 (1)
N1—H01⋯O2ⁱ	0.85 (2)	2.28 (2)	3.099 (1)	162 (1)
C3—H3⋯Sⁱⁱ	0.95	3.04	3.763 (1)	134
C17—H17C⋯Sⁱⁱⁱ	0.98	2.88	3.677 (1)	140

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

Acknowledgments

The authors are grateful to Allama Iqbal Open University, Islamabad, Pakistan, and Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Germany, for the research facilities.

supplementary crystallographic information

Comment

Epoxy resins have the combination of good thermal and dimensional stability, excellent chemical and corrosion resistance, high tensile strength and modulus, and ease of handling and processability, ensuring their wide application in the aerospace and electronic industries in the form of structural adhesives, advanced composite matrices, and packaging materials (Dušek, 1985). The properties of cured epoxy polymers largely depend on the nature of the chemical structure of the starting resins and curing agents. The title compound (I) is a precursor in an attempt to synthesize imidazole derivatives and transition metal complexes as epoxy resin curing agents and accelerators. Substituted thioureas are an important class of compounds, precursors or intermediates towards the synthesis of a variety of heterocyclic systems such as imidazole-2-thiones (Zeng et al., 2003), 2-imino-1, 3-thiazolines (D'hooghe et al., 2005), pyrimidine-2-thiones and (benzothiazolyl)-4-quinazolinones. Thioureas are also known to exhibit a wide range of biological activities including antiviral, antibacterial, antifungal, antitubercular, antithyroidal, herbicidal and insecticidal activities (Huebner et al., 1953) and as agrochemicals (Xu.Y et al., 2004). One example are 1-benzoyl-3-(4,5-disubstituted-pyrimidine-2-yl) thioureas, which have excellent herbicidal activity (W.Zheng et al., 2004). Thioureas are also well known chelating agents for transition metals (Xue et al.,2003). N,N-Dialkyl-N'-benzoyl thioureas act as selective complexing agents for the enrichment of platinum metals even from strongly interfacing matrixes.The complexes of thiourea derivatives also show various biological activities (Glasser et al., 1964). Thioureas and substituted thioureas are also known as epoxy resin curing agents. We became interested in the synthesis of N-Aroyl, N'-arylthioureas as intermediates towards some new novel heterocycles and for the systematic study of their bioactive complexes and epoxy resin curing agents. In this article, we describe the spectroscopy and crystal structure of ethyl 4-(3-benzoylthioureido)-benzoate (I) as a typical representative of N-aroyl, N'-arylthioureas. Compound (I) crystallizes in the thioamide form. The conformation of the molecule with respect to the carbonyl and thiocarbonyl part is essentially planar, as reflected by the torsional angles O1—C7—N1—C8, C7—N1—C8—S and C7—N1—C8—N2 of 0.7 (2), -177.97 (9) and 1.0 (2) °, respectively. However, there is rotation about the various moieties as indicated by e.g. C6—C1—C7—N1 34.7 (2) and C8—N2—C9—C14 136.9 (1) °. Apart from the atoms O1, N1, C8 and S, the molecule is planar (mean deviation of non-H atoms is 0.055 Å). The C7—O1, C8—S and C15—O2 bonds show a typical double bond character with bond lengths of 1.226 (1), 1.659 (1) and 1.215 (1) Å, respectively. All of the C—N bonds, C9—N2 1.415 (1), C7—N1 1.385 (1), C8—N2 1.339 (2), and C8—N1 1.401 (1) Å also indicate partial double bond character. Among the three latter C—N bonds, C7—N1 is the longest, indicating an C(sp²)—N(sp²) single bond, while C8—N2 is the shortest bond with more double bond character. This demonstrates that there is π conjugation in the system S—C8—N2 but not along O1—C7—N1 and C7—N1—C8, as found in 1-(3-methoxybenzoyl)-3,3-diethylthiourea (Moraless et al., 2000).

There is a strong intramolecular hydrogen bond N2—H02···O1, with distances H2···O1 1.89 (2) and N2···O1 2.618 (1) Å, resulting in a 6-membered ring. Molecules are connected in chains parallel to [101] by the classical H bond N1—H01···O2; weak C—H···S interactions are observed interconecting the chains (Table 1).

Experimental

The title compound was synthesized by a slight modification of the published procedure (Douglas et al., 1934). A solution of benzoyl chloride (0.1 mol) in anhydrous acetone (70 ml) was added dropwise to a suspension of ammonium thiocyanate (0.1 mol) in anhydrous acetone (50 ml) and the reaction mixture was refluxed for 45 minutes. After cooling to room temperature, a solution of p-aminobenzoic acid ethyl ester (0.1 mol) in anhydrous acetone (25 ml) was added and the resulting mixture refluxed for 1.5 hrs. The reaction mixture was poured into five times its volume of cold water where the thiourea precipitated as a solid. The product was recrystallized from ethyl acetate as pale yellow crystals (3.55 g, 85%). m.p. 425 K. Elemental analysis for C₁₇H₁₆N₂O₃S (M=328.38) calc. C 62.19, H 4.87, N 8.53, S 9.75, found C 62.16, H 4.93, N 8.58, S 9.76. FTIR (KBr pellet) [cm^-1]: 1276 (C=S), 1676 (C=O amide), 1700 (C=O ester), 3346 (free N—H), 3208 (assoc. N—H). ¹H-NMR (400 MHz, DMSO-d⁶) [ppm]: 1.34 (3H, t, CH₃); 4.32 (2H, q, CH₂); 7.51–7.56 (2H, m, CH_ar), 7.63–7.68 (2H, m, CH_ar), 7.90–8.00 (5H, m, CH_ar); 11.63 (1H, s, broad, NH); 12.80 (1H, s, broad, NH). ¹³C-NMR (300 MHz, DMSO-d⁶) [ppm]: 14.14 (CH₃); 60.70 (CH₂); 127.83(C), 128.72(C), 128.81(C), 129.72(C), 132.06(C), 133.17(C); 165.08(C=O amide); 168.20 (C=O ester), 178.99 (C=S thioamide).