N-Carbethoxy-N′-[3-(4-methylphenyl)-1H-1,2,4-triazol-5-yl]thiourea

Anton V Dolzhenko; Geok Kheng Tan; Lip Lin Koh; Anna V Dolzhenko; Wai Keung Chui

doi:10.1107/S1600536810004289

. 2010 Feb 6;66(Pt 3):o549–o550. doi: 10.1107/S1600536810004289

N-Carbethoxy-N′-[3-(4-methylphenyl)-1H-1,2,4-triazol-5-yl]thiourea

Anton V Dolzhenko ^a,^*, Geok Kheng Tan ^b, Lip Lin Koh ^b, Anna V Dolzhenko ^a, Wai Keung Chui ^a

PMCID: PMC2983713 PMID: 21580320

Abstract

The title compound, [systematic name: ethyl ({[3-(4-methylphenyl)-1H-1,2,4-triazol-5-yl]amino}carbonothioyl)carbamate], C₁₃H₁₆N₅O₂S, exists in the 3-aryl-5-thioureido-1H-1,2,4-triazole tautomeric form. The molecular structure is stabilized by intramolecular hydrogen bonding (N—H⋯S=C between the endocyclic N-bound H atom and the thioureido S atom, and N—H⋯O=C within the ethoxycarbonylthiourea unit), both arranged in an S(6) graph-set motif. The mean planes of the phenyl and 1,2,4-triazole rings make a dihedral angle of 6.59 (10)°. In the crystal structure, the molecules form two types of centrosymmetric dimers connected by intermolecular hydrogen bonds; in the first, the N—NH triazole sides of two molecules are connected [R ² ₂(6) graph-set motif] and the second is an N—H⋯S=C interaction between the imide H atoms and the thiocarbonyl S atoms [R ² ₂(8) graph-set motif]. Together, they form a network parallel to the (111) plane.

Related literature

For the synthesis, tautomerism and structures of related 1,2,4-triazoles, see: Dolzhenko et al. (2009a ▶,b ▶,c ▶, 2010 ▶); Buzykin et al. (2006 ▶). For related carbethoxythioureas, see: Dolzhenko et al. (2010 ▶); Huang et al. (2009 ▶); Lin et al. (2004 ▶, 2007 ▶); Su et al. (2006 ▶); Zhang et al. (2003 ▶, 2007 ▶). For the graph-set analysis of hydrogen bonding, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₃H₁₅N₅O₂S
M _r = 305.36
Triclinic,
a = 6.8430 (5) Å
b = 8.7789 (6) Å
c = 12.2563 (9) Å
α = 90.780 (1)°
β = 99.425 (1)°
γ = 101.279 (1)°
V = 711.52 (9) Å³
Z = 2
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 100 K
0.56 × 0.46 × 0.24 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T _min = 0.877, T _max = 0.945
9015 measured reflections
3243 independent reflections
3088 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.095
S = 1.07
3243 reflections
204 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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/S1600536810004289/kp2249sup1.cif

e-66-0o549-sup1.cif^{(18.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810004289/kp2249Isup2.hkl

e-66-0o549-Isup2.hkl^{(159.1KB, 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
N2—H2N⋯N3ⁱ	0.865 (19)	2.316 (19)	2.9719 (15)	132.8 (16)
N2—H2N⋯S1	0.865 (19)	2.660 (19)	3.1116 (11)	113.8 (15)
N4—H4N⋯O1	0.830 (19)	1.929 (18)	2.6274 (14)	141.2 (17)
N5—H5N⋯S1ⁱⁱ	0.856 (18)	2.576 (19)	3.4119 (11)	165.7 (16)

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

Acknowledgments

This work was supported by the National Medical Research Council, Singapore (grant No. NMRC/NIG/0019/2008).

supplementary crystallographic information

Comment

Recently, we reported the crystal structure of N-carbethoxy-N'-(3-phenyl-1H-1,2,4-triazol-5-yl)thiourea (Dolzhenko et al., 2010). Herein, in continuation of our investigations on annular tautomerism of 1,2,4-triazoles (Figs 3 and 4) in solutions (Dolzhenko et al., 2009a) and crystalline state (Dolzhenko et al., 2009b,c, 2010), we study the similar compound with methyl group presented in para-position of the phenyl ring. The electron donating effect of the methyl group might shift the tautomeric equilibrium towards the 5-aryl-3-thioureido-1H-1,2,4-triazole tautomeric form (Buzykin et al., 2006; Dolzhenko et al., 2009a). However, we found that this effect is not sufficient to alter the structure. Analogously to N-carbethoxy-N'-(3-phenyl-1H-1,2,4-triazol-5-yl)thiourea (Dolzhenko et al., 2010), the title compound crystallizes with similar molecular structure (Fig. 1) and packing (Fig. 2). The N2—H···S1 hydrogen bonding between the endocyclic N(3)H proton of the triazole ring and the thioureido sulfur S1 atom (Fig.1 and Table 1) arranged in a S(6) graph-set motif (Bernstein et al., 1995) is believed to be an essential factor stabilizing the tautomer. The triazole ring is planar with an r.m.s. deviation of 0.0069 Å. It makes a dihedral angle of 6.59 (10)° with the phenyl ring. The C10—N4 bond is significantly shorter (1.3414 (16) Å) than other C—N bonds of the carbethoxythiourea group (1.384–1.385 Å). Similarly to the previously reported related structures (Dolzhenko et al., 2010; Huang et al., 2009; Lin et al., 2007; Lin et al., 2004; Su et al., 2006; Zhang et al., 2007; Zhang et al., 2003), the carbethoxythiourea group of the title compound adopts (Z)-configuration across the thiourea C10—N4 bond and (E)-configuration across the C11—N5 bond. The strong intramolecular N4—H···O1═C11 hydrogen bonding arranged in common for carbethoxythioureas (Dolzhenko et al., 2010; Huang et al., 2009; Lin et al., 2007; Lin et al., 2004; Su et al., 2006; Zhang et al., 2007; Zhang et al., 2003) S(6) graph-set motif stabilizes this configuration.

In the crystal, the molecules form two types of centrosymmetric dimmers (Fig. 2, Table 1). The N3—N2H sides of two molecules are connected by intermolecular hydrogen bonds making the R²₂(6) graph-set motif. Atom N5 is also involved in the intermolecular N—H···S interaction with the thiocarbonyl atom S1 of adjacent molecule making another pair with the R²₂(8) graph-set motif similar to that observed in other carbethoxythioureas (Dolzhenko et al., 2010; Huang et al., 2009; Lin et al., 2007; Lin et al., 2004; Su et al., 2006; Zhang et al., 2007; Zhang et al., 2003). Together, these hydrogen bonds connect molecules in a network parallel to the (111) plane.

Experimental

The title compound (I) was synthesized by nucleophilic addition of 3(5)-amino-5(3)-(4-methylphenyl)-1H-1,2,4-triazole (Dolzhenko et al., 2009a) to ethoxycarbonyl isothiocyanate in DMF solution at room temperature (Fig. 3). Single crystals suitable for crystallographic analysis were grown by recrystallization from ethanol.