1-Allyl-3-amino-1H-pyrazole-4-carboxylic acid

Abstract

The title compound, C₇H₉N₃O₂, was prepared by alkaline hydrolysis of ethyl 1-allyl-3-amino-1H-pyrazole-4-carboxyl­ate. The crystal structure is stabilized by three types of inter­molecular hydrogen bond (N—H⋯O, N—H⋯N and O—H⋯N).

Related literature

For details of the biological activities of pyrazole derivatives, see: Malhotra et al. (1997 ▶); Takao et al. (1994 ▶); Wang et al. (2005 ▶).

Experimental

Crystal data

• C₇H₉N₃O₂

• M _r = 167.17

• Monoclinic,

• a = 8.966 (2) Å

• b = 8.531 (2) Å

• c = 10.266 (2) Å

• β = 95.57 (3)°

• V = 781.5 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 113 (2) K

• 0.20 × 0.18 × 0.14 mm

Data collection

• Rigaku Saturn CCD area-detector diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ▶) T _min = 0.979, T _max = 0.985

• 5773 measured reflections

• 1852 independent reflections

• 1631 reflections with I > 2σ(I)

• R _int = 0.025

Refinement

• R[F ² > 2σ(F ²)] = 0.034

• wR(F ²) = 0.085

• S = 1.06

• 1852 reflections

• 121 parameters

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

• Δρ_max = 0.29 e Å⁻³

• Δρ_min = −0.26 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; 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 DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2005 ▶).

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
N1—H1A⋯O1i	0.894 (16)	2.073 (16)	2.9652 (13)	175.7 (14)
N1—H1B⋯N2ii	0.905 (17)	2.457 (16)	3.2187 (14)	142.1 (13)
O2—H2A⋯N1iii	0.92 (2)	1.82 (2)	2.7232 (14)	166.8 (18)

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

supplementary crystallographic information

Comment

Pyrazole ring derivatives are very important substances in biology and have many application in the field of pesticide and pharmaceutical agents (Malhotra et al., 1997; Takao et al., 1994). Some of these compounds such as pyrazosufuron have been sold as agrochemicals (Wang et al., 2005).

Here we report the synthesis and crystal structure of the title compound, 1-allyl-3-amino-1H-pyrazole-4-carboxylic acid (Fig. 1). The crystal packing (Fig. 2) is stabilized by the intermolecular hydrogen bonds (Fig. 2 & Table 1).

Experimental

The mixture of ethyl 1-allyl-3-amino-1H-pyrazole-4-carboxylate (1.95 g, 10 mmol) in THF-MeOH (50 ml, v/v = 1/1) with 2.5N NaOH(25 ml) was heated at 333 K for 4 h. The solvent was removed under reduced pressure and the residue was acidified with 6N HCl at 273 K. A gray solid was precipitated, filtered, and washed with water. Single crystals suitable for X-ray diffraction were obtained by recrystallization of the title compound in ethanol.

Refinement

H atoms of N1 and O2 were positioned in a difference Fourier maps and their parameters were freely refined. The other H atoms were placed in calculated positions, with C—H = 0.95 or 0.99 Å, and and O—H = 0.82 Å, and included in the final cycles of refinement using a riding model, with U_iso(H) = 1.2Ueq(C).

Figures

Fig. 1.

The molecular structure of the title compound, showing displacement ellipsoids drawn at the 50% probability level.

Fig. 2.

Hydrogenbonds interactions (dotted lines) in the title compound. [symmetry code; (i) -x+1, y-1/2, -z+3/2; (ii) -x+1, y+1/2, -z+3/2; (iii) x, -y+3/2, z-1/2.]

Crystal data

C7H9N3O2	F000 = 352
Mr = 167.17	Dx = 1.421 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2299 reflections
a = 8.966 (2) Å	θ = 2.4–27.9º
b = 8.531 (2) Å	µ = 0.11 mm−1
c = 10.266 (2) Å	T = 113 (2) K
β = 95.57 (3)º	Prism, colorless
V = 781.5 (3) Å3	0.20 × 0.18 × 0.14 mm
Z = 4

Data collection

Rigaku Saturn CCD area-detector diffractometer	1852 independent reflections
Radiation source: rotating anode	1631 reflections with I > 2σ(I)
Monochromator: confocal	Rint = 0.025
Detector resolution: 7.31 pixels mm-1	θmax = 27.9º
T = 113(2) K	θmin = 3.1º
ω and φ scans	h = −7→11
Absorption correction: Multi-scan(CrystalClear; Rigaku/MSC, 2005)	k = −11→11
Tmin = 0.979, Tmax = 0.985	l = −13→13
5773 measured 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)] = 0.034	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.085	w = 1/[σ2(Fo2) + (0.0353P)2 + 0.3376P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max < 0.001
1852 reflections	Δρmax = 0.29 e Å−3
121 parameters	Δρmin = −0.25 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
C1	0.64833 (12)	0.69316 (12)	0.51583 (10)	0.0123 (2)
C2	0.68026 (12)	0.53444 (13)	0.56126 (10)	0.0122 (2)
C3	0.63332 (12)	0.46275 (12)	0.67507 (10)	0.0116 (2)
C4	0.75001 (12)	0.41422 (13)	0.49875 (10)	0.0134 (2)
H4	0.7935	0.4217	0.4182	0.016*
C5	0.79757 (13)	0.12954 (13)	0.54567 (11)	0.0149 (2)
H5A	0.8212	0.1241	0.4536	0.018*
H5B	0.7169	0.0529	0.5570	0.018*
C6	0.93408 (13)	0.08629 (14)	0.63419 (11)	0.0177 (2)
H6	1.0204	0.1508	0.6340	0.021*
C7	0.94070 (15)	−0.03654 (16)	0.71224 (12)	0.0238 (3)
H7A	0.8560	−0.1030	0.7143	0.029*
H7B	1.0302	−0.0587	0.7665	0.029*
N1	0.55906 (11)	0.53395 (11)	0.77249 (9)	0.0132 (2)
H1A	0.5169 (17)	0.4628 (18)	0.8213 (15)	0.024 (4)*
H1B	0.4929 (18)	0.6087 (19)	0.7423 (15)	0.025 (4)*
N2	0.67310 (10)	0.31234 (11)	0.68348 (9)	0.0128 (2)
N3	0.74458 (10)	0.28673 (11)	0.57279 (9)	0.0128 (2)
O1	0.57152 (9)	0.78485 (9)	0.57215 (8)	0.01648 (19)
O2	0.70880 (9)	0.72908 (10)	0.40620 (8)	0.01749 (19)
H2A	0.663 (2)	0.818 (2)	0.3719 (19)	0.049 (5)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0129 (5)	0.0125 (5)	0.0113 (5)	−0.0016 (4)	0.0006 (4)	0.0004 (4)
C2	0.0130 (5)	0.0122 (5)	0.0114 (5)	0.0000 (4)	0.0007 (4)	0.0000 (4)
C3	0.0118 (5)	0.0113 (5)	0.0114 (5)	−0.0008 (4)	0.0001 (4)	−0.0012 (4)
C4	0.0141 (5)	0.0142 (5)	0.0119 (5)	0.0006 (4)	0.0016 (4)	0.0012 (4)
C5	0.0187 (5)	0.0114 (5)	0.0151 (5)	0.0026 (4)	0.0029 (4)	−0.0025 (4)
C6	0.0151 (5)	0.0168 (6)	0.0215 (5)	0.0026 (4)	0.0032 (4)	−0.0032 (4)
C7	0.0237 (6)	0.0262 (7)	0.0216 (6)	0.0075 (5)	0.0021 (5)	0.0031 (5)
N1	0.0170 (5)	0.0104 (4)	0.0127 (4)	0.0009 (4)	0.0043 (4)	0.0006 (3)
N2	0.0148 (4)	0.0124 (5)	0.0114 (4)	0.0007 (3)	0.0032 (3)	−0.0012 (3)
N3	0.0146 (4)	0.0124 (5)	0.0116 (4)	0.0015 (3)	0.0027 (3)	−0.0010 (3)
O1	0.0215 (4)	0.0125 (4)	0.0160 (4)	0.0026 (3)	0.0048 (3)	−0.0005 (3)
O2	0.0216 (4)	0.0160 (4)	0.0160 (4)	0.0043 (3)	0.0077 (3)	0.0058 (3)

Geometric parameters (Å, °)

C1—O1	1.2238 (13)	C5—H5A	0.9900
C1—O2	1.3316 (13)	C5—H5B	0.9900
C1—C2	1.4516 (15)	C6—C7	1.3170 (17)
C2—C4	1.3902 (15)	C6—H6	0.9500
C2—C3	1.4182 (14)	C7—H7A	0.9500
C3—N2	1.3323 (14)	C7—H7B	0.9500
C3—N1	1.3936 (14)	N1—H1A	0.894 (16)
C4—N3	1.3305 (14)	N1—H1B	0.905 (17)
C4—H4	0.9500	N2—N3	1.3752 (13)
C5—N3	1.4585 (14)	O2—H2A	0.92 (2)
C5—C6	1.4980 (16)
O1—C1—O2	123.11 (10)	C6—C5—H5B	109.2
O1—C1—C2	123.16 (10)	H5A—C5—H5B	107.9
O2—C1—C2	113.73 (9)	C7—C6—C5	123.43 (11)
C4—C2—C3	104.18 (9)	C7—C6—H6	118.3
C4—C2—C1	128.56 (10)	C5—C6—H6	118.3
C3—C2—C1	127.00 (10)	C6—C7—H7A	120.0
N2—C3—N1	121.12 (10)	C6—C7—H7B	120.0
N2—C3—C2	111.70 (9)	H7A—C7—H7B	120.0
N1—C3—C2	127.15 (10)	C3—N1—H1A	111.3 (10)
N3—C4—C2	107.24 (9)	C3—N1—H1B	113.8 (10)
N3—C4—H4	126.4	H1A—N1—H1B	111.8 (14)
C2—C4—H4	126.4	C3—N2—N3	104.05 (9)
N3—C5—C6	111.89 (9)	C4—N3—N2	112.83 (9)
N3—C5—H5A	109.2	C4—N3—C5	127.73 (9)
C6—C5—H5A	109.2	N2—N3—C5	119.37 (9)
N3—C5—H5B	109.2	C1—O2—H2A	108.1 (12)
O1—C1—C2—C4	171.64 (11)	N3—C5—C6—C7	121.64 (12)
O2—C1—C2—C4	−7.54 (16)	N1—C3—N2—N3	−178.90 (9)
O1—C1—C2—C3	−1.60 (17)	C2—C3—N2—N3	−0.81 (12)
O2—C1—C2—C3	179.22 (10)	C2—C4—N3—N2	0.52 (12)
C4—C2—C3—N2	1.12 (12)	C2—C4—N3—C5	177.29 (10)
C1—C2—C3—N2	175.67 (10)	C3—N2—N3—C4	0.18 (12)
C4—C2—C3—N1	179.07 (10)	C3—N2—N3—C5	−176.89 (9)
C1—C2—C3—N1	−6.38 (18)	C6—C5—N3—C4	109.64 (12)
C3—C2—C4—N3	−0.95 (12)	C6—C5—N3—N2	−73.77 (12)
C1—C2—C4—N3	−175.38 (10)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1i	0.894 (16)	2.073 (16)	2.9652 (13)	175.7 (14)
N1—H1B···N2ii	0.905 (17)	2.457 (16)	3.2187 (14)	142.1 (13)
O2—H2A···N1iii	0.92 (2)	1.82 (2)	2.7232 (14)	166.8 (18)

Symmetry codes: (i) −x+1, y−1/2, −z+3/2; (ii) −x+1, y+1/2, −z+3/2; (iii) x, −y+3/2, z−1/2.