4-Amino-3-(4-hydroxy­phen­yl)-1H-1,2,4-triazol-5(4H)-one

Abstract

The mol­ecule of the title compound, C₈H₈N₄O₂, is nearly planar, with a dihedral angle between the rings of 1.1 (1)°. Adjacent mol­ecules are linked into a layered structure by hydr­oxy–oxo O—H⋯O and triazol­yl–hydr­oxy N—H⋯O hydrogen bonds. Only one of the H atoms of the pyramidal amino group is engaged in building up the infinite layer. The second H atom of the amino group also shows hydrogen-bonding inter­actions, linking adjacent layers into a three-dimensional network.

Related literature

For a synthesis of the title compound using CS₂ as a reactant, see: Chande & Singh-Jathar (1998 ▶). This product was obtained unexpectedly in the present study.

Experimental

Crystal data

• C₈H₈N₄O₂

• M _r = 192.18

• Triclinic,

• a = 6.534 (1) Å

• b = 7.330 (1) Å

• c = 9.804 (1) Å

• α = 106.69 (1)°

• β = 102.328 (9)°

• γ = 106.712 (2)°

• V = 407.7 (1) ų

• Z = 2

• Mo Kα radiation

• μ = 0.12 mm⁻¹

• T = 295 (2) K

• 0.25 × 0.16 × 0.04 mm

Data collection

• Bruker APEXII area-detector diffractometer

• Absorption correction: none

• 3032 measured reflections

• 1434 independent reflections

• 1115 reflections with I > 2σ(I)

• R _int = 0.017

Refinement

• R[F ² > 2σ(F ²)] = 0.039

• wR(F ²) = 0.109

• S = 1.03

• 1434 reflections

• 143 parameters

• 4 restraints

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.14 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Supplementary Material

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
O1—H1⋯O2i	0.86 (1)	1.78 (1)	2.633 (2)	175 (3)
N2—H2⋯O1ii	0.86 (1)	1.93 (1)	2.789 (2)	173 (2)
N4—H4⋯O2iii	0.87 (1)	2.24 (1)	3.077 (3)	163 (2)

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

supplementary crystallographic information

Comment

In connection with our work on metal triazolates, we are interested in synthesizing 4-amino-bis(4-hydroxyphenyl)-1,2,4-triazole. The synthesis of this triazole yielded the title compound as an unexpected product. A specific procedure for the synthesis of the title compound is reported in the literature to start from carbonyl sulfide and 4-hydroxybenzohydrazide in potassium hydroxide to give a precursor that was subsequently reacted with hydrazine (Chande & Singh-Jathar, 1998).

Experimental

4-Hydroxybenzoic acid (2.76 g, 0.02 mol) and 80% hydrazine hydrate (1.55 g, 0.02 mol) were heated in a sealed tube at 439 K for three days. After cooling to room temperature, the mixture was centrifuged. The resulting white solid was suspended in water, and 6M hydrochloric acid was added until the pH was 3. The white product was collected and recrystallized from a DMSO–water mixture(10:1) to afford colorless crystals in 3% yield. CH&N elemental analysis. C 49.58 (calc. 49.99), H 4.19 (found 4.20), N 29.25% (29.15%).

Refinement

Carbon-bound H atoms were generated geometrically (C–H 0.93 Å), and were included in the refinement in the riding model approximation, with U(H) set to 1.2U_eq(C). The amino and hydroxy H atoms were located in a difference Fourier map, and were refined with distance restraints of N–H = O–H = 0.85±0.01 Å; their temperature factors were freely refined.

Figures

Fig. 1.

Thermal ellipsoid (Barbour, 2001) plot of C18H8N4O2 at the 70% probability level.

Fig. 2.

Thermal ellipsoid (Barbour, 2001) plot of the layered structure arising from O–Hhydroxy and N–Htriazolyl hydrogen bonds.

Crystal data

C8H8N4O2	Z = 2
Mr = 192.18	F000 = 200
Triclinic, P1	Dx = 1.565 Mg m−3
Hall symbol: -P 1	Mo Kα radiation λ = 0.71073 Å
a = 6.534 (1) Å	Cell parameters from 986 reflections
b = 7.330 (1) Å	θ = 2.3–26.7º
c = 9.804 (1) Å	µ = 0.12 mm−1
α = 106.69 (1)º	T = 295 (2) K
β = 102.328 (9)º	Block, colorless
γ = 106.712 (2)º	0.25 × 0.16 × 0.04 mm
V = 407.7 (1) Å3

Data collection

Bruker APEXII area-detector diffractometer	1115 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.017
Monochromator: graphite	θmax = 25.0º
T = 295(2) K	θmin = 2.3º
φ and ω scans	h = −7→7
Absorption correction: None	k = −8→8
3032 measured reflections	l = −11→11
1434 independent reflections

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.039	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.109	w = 1/[σ2(Fo2) + (0.0565P)2 + 0.1018P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max = 0.001
1434 reflections	Δρmax = 0.14 e Å−3
143 parameters	Δρmin = −0.19 e Å−3
4 restraints	Extinction correction: none
Primary atom site location: structure-invariant direct methods

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.3462 (2)	0.3381 (2)	0.06978 (15)	0.0481 (4)
O2	0.6706 (2)	1.2219 (2)	1.00449 (15)	0.0456 (4)
N1	0.8848 (3)	1.0137 (3)	0.72942 (18)	0.0423 (5)
N2	0.9057 (3)	1.1419 (3)	0.87015 (19)	0.0444 (5)
N3	0.5523 (2)	0.9858 (2)	0.75552 (16)	0.0319 (4)
N4	0.3171 (3)	0.9141 (3)	0.7256 (2)	0.0420 (5)
C1	0.7075 (3)	1.1281 (3)	0.8902 (2)	0.0361 (5)
C2	0.6672 (3)	0.9197 (3)	0.6610 (2)	0.0314 (4)
C3	0.5739 (3)	0.7693 (3)	0.5056 (2)	0.0302 (4)
C4	0.3450 (3)	0.6652 (3)	0.4264 (2)	0.0373 (5)
H4A	0.2398	0.6910	0.4719	0.045*
C5	0.2715 (3)	0.5241 (3)	0.2810 (2)	0.0402 (5)
H5	0.1177	0.4571	0.2289	0.048*
C6	0.4261 (3)	0.4820 (3)	0.2127 (2)	0.0342 (5)
C7	0.6551 (3)	0.5851 (3)	0.2893 (2)	0.0387 (5)
H7	0.7598	0.5593	0.2432	0.046*
C8	0.7269 (3)	0.7262 (3)	0.4342 (2)	0.0386 (5)
H8	0.8808	0.7942	0.4854	0.046*
H1	0.450 (3)	0.301 (4)	0.043 (3)	0.067 (8)*
H2	1.037 (2)	1.204 (3)	0.937 (2)	0.054 (7)*
H4	0.294 (5)	0.881 (4)	0.801 (2)	0.076 (9)*
H40	0.273 (4)	1.013 (3)	0.732 (3)	0.078 (10)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0338 (8)	0.0580 (10)	0.0293 (8)	0.0155 (7)	0.0038 (6)	−0.0101 (7)
O2	0.0431 (9)	0.0556 (9)	0.0288 (8)	0.0213 (7)	0.0126 (6)	−0.0008 (7)
N1	0.0305 (9)	0.0498 (10)	0.0295 (9)	0.0122 (8)	0.0071 (7)	−0.0045 (8)
N2	0.0288 (9)	0.0540 (11)	0.0268 (9)	0.0114 (8)	0.0029 (7)	−0.0095 (8)
N3	0.0271 (8)	0.0396 (9)	0.0245 (8)	0.0135 (7)	0.0099 (6)	0.0032 (7)
N4	0.0295 (9)	0.0559 (12)	0.0343 (10)	0.0172 (9)	0.0124 (8)	0.0053 (9)
C1	0.0347 (11)	0.0406 (11)	0.0262 (10)	0.0156 (9)	0.0081 (8)	0.0025 (9)
C2	0.0301 (10)	0.0349 (10)	0.0259 (10)	0.0132 (8)	0.0097 (8)	0.0051 (8)
C3	0.0312 (10)	0.0325 (10)	0.0255 (10)	0.0135 (8)	0.0103 (8)	0.0061 (8)
C4	0.0309 (10)	0.0442 (12)	0.0320 (11)	0.0165 (9)	0.0111 (8)	0.0042 (9)
C5	0.0264 (10)	0.0472 (12)	0.0343 (11)	0.0120 (9)	0.0056 (8)	0.0023 (9)
C6	0.0339 (11)	0.0380 (11)	0.0246 (10)	0.0136 (9)	0.0075 (8)	0.0043 (8)
C7	0.0316 (11)	0.0476 (12)	0.0297 (11)	0.0153 (9)	0.0124 (8)	0.0019 (9)
C8	0.0276 (10)	0.0450 (12)	0.0310 (11)	0.0110 (9)	0.0067 (8)	0.0017 (9)

Geometric parameters (Å, °)

O1—C6	1.368 (2)	C2—C3	1.470 (2)
O1—H1	0.861 (10)	C3—C4	1.389 (3)
O2—C1	1.247 (2)	C3—C8	1.394 (3)
N1—C2	1.308 (2)	C4—C5	1.381 (3)
N1—N2	1.381 (2)	C4—H4A	0.9300
N2—C1	1.331 (3)	C5—C6	1.383 (3)
N2—H2	0.860 (10)	C5—H5	0.9300
N3—C1	1.374 (2)	C6—C7	1.385 (3)
N3—C2	1.380 (2)	C7—C8	1.379 (3)
N3—N4	1.407 (2)	C7—H7	0.9300
N4—H4	0.868 (10)	C8—H8	0.9300
N4—H40	0.846 (10)
C6—O1—H1	112.3 (18)	C4—C3—C2	124.64 (17)
C2—N1—N2	104.87 (15)	C8—C3—C2	117.37 (17)
C1—N2—N1	112.93 (16)	C5—C4—C3	120.93 (18)
C1—N2—H2	127.2 (16)	C5—C4—H4A	119.5
N1—N2—H2	119.0 (16)	C3—C4—H4A	119.5
C1—N3—C2	108.48 (15)	C4—C5—C6	120.17 (18)
C1—N3—N4	124.53 (15)	C4—C5—H5	119.9
C2—N3—N4	126.90 (16)	C6—C5—H5	119.9
N3—N4—H4	105.8 (19)	O1—C6—C5	118.31 (17)
N3—N4—H40	109.5 (19)	O1—C6—C7	121.86 (17)
H4—N4—H40	104 (3)	C5—C6—C7	119.83 (17)
O2—C1—N2	128.18 (18)	C8—C7—C6	119.58 (18)
O2—C1—N3	127.92 (18)	C8—C7—H7	120.2
N2—C1—N3	103.90 (16)	C6—C7—H7	120.2
N1—C2—N3	109.81 (15)	C7—C8—C3	121.49 (18)
N1—C2—C3	121.80 (16)	C7—C8—H8	119.3
N3—C2—C3	128.39 (16)	C3—C8—H8	119.3
C4—C3—C8	117.99 (17)
C2—N1—N2—C1	0.4 (2)	N3—C2—C3—C4	−0.2 (3)
N1—N2—C1—O2	179.29 (19)	N1—C2—C3—C8	1.5 (3)
N1—N2—C1—N3	−0.6 (2)	N3—C2—C3—C8	−179.08 (18)
C2—N3—C1—O2	−179.4 (2)	C8—C3—C4—C5	−0.3 (3)
N4—N3—C1—O2	−2.7 (3)	C2—C3—C4—C5	−179.17 (18)
C2—N3—C1—N2	0.5 (2)	C3—C4—C5—C6	0.9 (3)
N4—N3—C1—N2	177.19 (19)	C4—C5—C6—O1	178.66 (18)
N2—N1—C2—N3	−0.1 (2)	C4—C5—C6—C7	−1.4 (3)
N2—N1—C2—C3	179.42 (17)	O1—C6—C7—C8	−178.87 (18)
C1—N3—C2—N1	−0.2 (2)	C5—C6—C7—C8	1.2 (3)
N4—N3—C2—N1	−176.86 (19)	C6—C7—C8—C3	−0.5 (3)
C1—N3—C2—C3	−179.71 (18)	C4—C3—C8—C7	0.1 (3)
N4—N3—C2—C3	3.7 (3)	C2—C3—C8—C7	179.05 (18)
N1—C2—C3—C4	−179.6 (2)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2i	0.86 (1)	1.78 (1)	2.633 (2)	175 (3)
N2—H2···O1ii	0.86 (1)	1.93 (1)	2.789 (2)	173 (2)
N4—H4···O2iii	0.87 (1)	2.24 (1)	3.077 (3)	163 (2)

Symmetry codes: (i) x, y−1, z−1; (ii) x+1, y+1, z+1; (iii) −x+1, −y+2, −z+2.