(3,5-Di­methyl­pyrazol-1-yl)­acetic acid

Boa, A.N.; Crane, J.D.

doi:10.1107/S1600536804010761

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 60| Part 6| June 2004| Pages o966-o967

https://doi.org/10.1107/S1600536804010761

(3,5-Dimethylpyrazol-1-yl)acetic acid

Andrew N Boa ^a and Jonathan D Crane ^a ^*

^aDepartment of Chemistry, University of Hull, Cottingham Road, Kingston-upon-Hull HU6 7RX, England
^*Correspondence e-mail: j.d.crane@hull.ac.uk

(Received 27 April 2004; accepted 4 May 2004; online 8 May 2004)

At 150 K, the title compound, C₇H₁₀N₂O₂, comprises one-dimensional hydrogen-bonded homochiral helical chains of molecules.

Comment

The molecular structure of the title compound, (I), is shown in Fig. 1 and selected structural parameters are listed in Table 1. The least-squares planes of the pyrazole ring and the carboxylic acid group are almost mutually perpendicular, with a dihedral angle of 87.57 (7)°, and atom N2 is close to being coplanar with the carboxylic acid group, lying only 0.0067 (15) Å out of the least-squares plane of the latter. The molecules form homochiral helical hydrogen-bonded chains parallel to the b axis (Fig. 2 and Table 2).

Figure 1
View of the molecule of (I

), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are represented by circles of arbitrary size.

Figure 2
The packing and unit cell of (I

), viewed approximately down the a axis. Hydrogen bonds are denoted by dashed lines.

Experimental

The title compound, (I), was prepared according to the method of Micetich (1970 ).

Crystal data

C₇H₁₀N₂O₂
M_r = 154.17
Orthorhombic, P2₁2₁2₁
a = 4.8528 (4) Å
b = 7.0073 (6) Å
c = 23.256 (3) Å
V = 790.82 (13) Å³
Z = 4
D_x = 1.295 Mg m⁻³
Mo Kα radiation
Cell parameters from 6939 reflections
θ = 3.0–34.8°
μ = 0.10 mm⁻¹
T = 150 (2) K
Lath, colourless
0.60 × 0.25 × 0.10 mm

Data collection

Stoe IPDS-II area-detector diffractometer
φ and ω scans
Absorption correction: none
11979 measured reflections
2013 independent reflections
1357 reflections with I > 2σ(I)
R_int = 0.057
θ_max = 34.8°
h = −7 → 6
k = −11 → 10
l = −37 → 37

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.147
S = 1.05
2013 reflections
107 parameters
H atoms treated by a mixture of independent and constrained refinement
w = 1/[σ²(F_o²) + (0.0896P)²] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max < 0.001
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.26 e Å⁻³
Extinction correction: SHELXL97
Extinction coefficient: 0.088 (15)

Table 1
Selected geometric parameters (Å, °)

O1—C5	1.318 (2)
O2—C5	1.201 (2)
N1—N2	1.359 (2)
N2—C3	1.348 (2)
C2—C3	1.381 (3)
C1—C2	1.407 (3)
N1—C1	1.331 (2)
N2—C4	1.451 (2)
C4—C5	1.514 (3)

N1—N2—C4	119.87 (14)
N2—C4—C5	110.48 (15)
O2—C5—O1	124.93 (18)

N1—N2—C4—C5	87.48 (19)
N2—C4—C5—O2	0.7 (3)

Table 2
Hydrogen-bonding geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1ⁱ	0.95 (3)	1.79 (3)	2.723 (2)	169 (3)
Symmetry code: (i) $[2-x,y-{\script{1\over 2}},{\script{1\over 2}}-z]$ .

All H atoms were initially located in a difference Fourier map. The positional and isotropic displacement parameters for the hydroxyl H atom were freely refined. The methyl H atoms were constrained to an ideal geometry, with a C—H distance of 0.98 Å, but each group was allowed to rotate freely about its X—C bond. All other C—H atoms were placed in geometrically idealized positions, with C—H distances of 0.95–0.99 Å. U_iso(H) values were set at 1.2U_eq(C) for all C—H atoms.

Data collection: X-AREA (Stoe, 2001 ); cell refinement: X-AREA; data reduction: X-RED32 (Stoe, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ) and PLATON (Spek, 2001 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536804010761/su6099sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536804010761/su6099Isup2.hkl

Computing details top

Data collection: X-AREA (Stoe, 2001); cell refinement: X-AREA; data reduction: X-RED (Stoe, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2001).

(3,5-Dimethyl-pyrazol-1-yl)acetic acid top

Crystal data top

C₇H₁₀N₂O₂	F(000) = 328
M_r = 154.17	D_x = 1.295 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 6939 reflections
a = 4.8528 (4) Å	θ = 3.0–34.8°
b = 7.0073 (6) Å	µ = 0.10 mm⁻¹
c = 23.256 (3) Å	T = 150 K
V = 790.82 (13) Å³	Lath, colourless
Z = 4	0.60 × 0.25 × 0.10 mm

Data collection top

Stoe IPDS-II area-detector diffractometer	1357 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.057
Graphite monochromator	θ_max = 34.8°, θ_min = 3.0°
φ and ω scans	h = −7→6
11979 measured reflections	k = −11→10
2013 independent reflections	l = −37→37

Refinement top

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)] = 0.049	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.147	w = 1/[σ²(F_o²) + (0.0896P)²] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
2013 reflections	Δρ_max = 0.26 e Å⁻³
107 parameters	Δρ_min = −0.26 e Å⁻³
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.088 (15)

Special details top

Experimental. The crystal was mounted under the perfluoro-polyether PFO-XR75 (Lancaster Synthesis). A total of 183 frames (3 minute exposure) were collected (phi/omega: 60/0–150, 140/0–33 delta-omega = 1 °.)

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

Weighted least-squares planes through the starred atoms (Nardelli, Musatti, Domiano & Andreetti Ric·Sci.(1965),15(II—A),807).

Plane 1 Atom d s d/s (d/s)**2 N1 * 0.0052 0.0016 3.329 11.084 N2 * -0.0068 0.0015 - 4.436 19.679 C1 * -0.0023 0.0019 - 1.194 1.425 C2 * -0.0046 0.0021 - 2.203 4.852 C3 * 0.0093 0.0020 4.733 22.397 C4 0.1719 0.0019 91.699 8408.692 C6 0.0192 0.0022 8.748 76.533 C7 0.0805 0.0025 31.975 1022.373 ============ Sum((d/s)**2) for starred atoms 59.437 Chi-squared at 95% for 2 degrees of freedom: 5.99

Plane 2 Atom d s d/s (d/s)**2 C4 * -0.0018 0.0019 - 0.939 0.882 C5 * 0.0065 0.0019 3.369 11.352 O1 * -0.0012 0.0015 - 0.843 0.710 O2 * -0.0029 0.0020 - 1.409 1.984 N2 - 0.0067 0.0015 - 4.325 18.707 ============ Sum((d/s)**2) for starred atoms 14.928 Chi-squared at 95% for 1 degrees of freedom: 3.84

Dihedral angles formed by LSQ-planes Plane - plane angle (s.u.) angle (s.u.) 1 2 87.57 (0.07) 92.43 (0.07)

Possible hydrogen bonds Donor-H Donor···Acceptor H···Acceptor Donor-H······Acceptor

O1 –H1 O1 ···N1 (1) H1 ···N1 (1) O1 –H1 ···N1 (1) 0.945(.029) 2.723(.002) 1.788(.029) 169.21 (2.64)

C4 –H4A C4 ···O2 (3) H4A ···O2 (3) C4 –H4A ···O2 (3) 0.990(.002) 3.090(.003) 2.369(.002) 128.98 (0.12)

C4 –H4B C4 ···O2 (4) H4B ···O2 (4) C4 –H4B ···O2 (4) 0.990(.002) 3.203(.003) 2.295(.002) 152.05 (0.12)

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 > σ(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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.7445 (3)	0.7871 (2)	0.20669 (6)	0.0365 (3)
H1	0.857 (6)	0.711 (4)	0.1827 (11)	0.047 (7)*
O2	1.0832 (3)	0.7353 (3)	0.26981 (7)	0.0506 (5)
N1	0.9883 (3)	1.0557 (2)	0.36906 (6)	0.0305 (3)
N2	0.8155 (3)	0.9087 (2)	0.35669 (6)	0.0302 (3)
C1	1.1052 (4)	1.0099 (3)	0.41895 (7)	0.0324 (4)
C2	1.0090 (5)	0.8317 (3)	0.43831 (8)	0.0359 (4)
H2	1.0595	0.7673	0.4727	0.043*
C3	0.8258 (4)	0.7701 (3)	0.39683 (7)	0.0340 (4)
C4	0.6802 (4)	0.9005 (3)	0.30112 (7)	0.0322 (3)
H4A	0.6406	1.0316	0.2876	0.039*
H4B	0.5028	0.8318	0.3049	0.039*
C5	0.8611 (4)	0.7992 (3)	0.25772 (7)	0.0315 (4)
C6	1.3125 (5)	1.1405 (3)	0.44582 (8)	0.0396 (4)
H6A	1.3129	1.2628	0.4254	0.048*
H6B	1.4959	1.0825	0.4434	0.048*
H6C	1.2644	1.1617	0.4862	0.048*
C7	0.6677 (5)	0.5879 (3)	0.39156 (10)	0.0459 (5)
H7A	0.7373	0.5148	0.3587	0.055*
H7B	0.4721	0.6166	0.3857	0.055*
H7C	0.6901	0.5127	0.4268	0.055*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0385 (7)	0.0411 (7)	0.0300 (5)	0.0043 (6)	−0.0031 (5)	−0.0059 (5)
O2	0.0321 (7)	0.0757 (12)	0.0439 (8)	0.0119 (8)	−0.0075 (6)	−0.0208 (8)
N1	0.0321 (7)	0.0315 (7)	0.0277 (6)	−0.0024 (6)	0.0000 (6)	−0.0027 (5)
N2	0.0305 (7)	0.0306 (6)	0.0295 (6)	−0.0011 (6)	0.0010 (6)	−0.0022 (5)
C1	0.0319 (8)	0.0369 (9)	0.0284 (7)	−0.0021 (7)	0.0020 (7)	−0.0011 (6)
C2	0.0388 (9)	0.0390 (9)	0.0299 (7)	−0.0019 (8)	0.0000 (7)	0.0040 (7)
C3	0.0353 (9)	0.0345 (8)	0.0322 (7)	−0.0027 (8)	0.0035 (7)	0.0012 (6)
C4	0.0297 (8)	0.0361 (8)	0.0309 (7)	0.0010 (7)	−0.0026 (7)	−0.0019 (6)
C5	0.0287 (8)	0.0342 (8)	0.0316 (7)	−0.0040 (7)	−0.0017 (6)	−0.0030 (6)
C6	0.0402 (10)	0.0454 (10)	0.0334 (8)	−0.0074 (9)	−0.0029 (8)	−0.0033 (8)
C7	0.0528 (13)	0.0390 (10)	0.0457 (10)	−0.0127 (10)	−0.0002 (10)	0.0028 (8)

Geometric parameters (Å, º) top

O1—C5	1.318 (2)	C2—H2	0.9500
O1—H1	0.95 (3)	C3—C7	1.495 (3)
O2—C5	1.201 (2)	C4—H4A	0.9900
N1—N2	1.359 (2)	C4—H4B	0.9900
N2—C3	1.348 (2)	C6—H6A	0.9800
C2—C3	1.381 (3)	C6—H6B	0.9800
C1—C2	1.407 (3)	C6—H6C	0.9800
N1—C1	1.331 (2)	C7—H7A	0.9800
N2—C4	1.451 (2)	C7—H7B	0.9800
C4—C5	1.514 (3)	C7—H7C	0.9800
C1—C6	1.497 (3)

C5—O1—H1	108.5 (17)	C5—C4—H4B	109.6
C1—N1—N2	105.34 (15)	H4A—C4—H4B	108.1
C3—N2—N1	112.12 (15)	O2—C5—O1	124.93 (18)
C3—N2—C4	127.23 (16)	O2—C5—C4	122.63 (17)
N1—N2—C4	119.87 (14)	O1—C5—C4	112.42 (16)
N1—C1—C2	110.60 (17)	C1—C6—H6A	109.5
N1—C1—C6	120.19 (17)	C1—C6—H6B	109.5
C2—C1—C6	129.19 (18)	H6A—C6—H6B	109.5
C3—C2—C1	105.50 (16)	C1—C6—H6C	109.5
C3—C2—H2	127.3	H6A—C6—H6C	109.5
C1—C2—H2	127.3	H6B—C6—H6C	109.5
N2—C3—C2	106.42 (17)	C3—C7—H7A	109.5
N2—C3—C7	122.65 (17)	C3—C7—H7B	109.5
C2—C3—C7	130.89 (18)	H7A—C7—H7B	109.5
N2—C4—C5	110.48 (15)	C3—C7—H7C	109.5
N2—C4—H4A	109.6	H7A—C7—H7C	109.5
C5—C4—H4A	109.6	H7B—C7—H7C	109.5
N2—C4—H4B	109.6

C1—N1—N2—C3	−1.4 (2)	N1—N2—C3—C7	−176.37 (18)
C1—N1—N2—C4	−172.01 (16)	C4—N2—C3—C7	−6.6 (3)
N2—N1—C1—C2	0.6 (2)	C1—C2—C3—N2	−1.1 (2)
N2—N1—C1—C6	179.48 (17)	C1—C2—C3—C7	176.6 (2)
N1—C1—C2—C3	0.3 (2)	C3—N2—C4—C5	−81.6 (2)
C6—C1—C2—C3	−178.4 (2)	N1—N2—C4—C5	87.48 (19)
N1—N2—C3—C2	1.6 (2)	N2—C4—C5—O2	0.7 (3)
C4—N2—C3—C2	171.38 (18)	N2—C4—C5—O1	179.42 (15)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1ⁱ	0.95 (3)	1.79 (3)	2.723 (2)	169 (3)

Symmetry code: (i) −x+2, y−1/2, −z+1/2.

References

Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Micetich, R. G. (1970). Can. J. Chem. 48, 2006–2015. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar
Spek, A. L. (2001). PLATON. University of Utrecht, The Netherlands. Google Scholar
Stoe. (2001). X-AREA and X-RED32. Stoe & Cie GmbH, Darmstadt, Germany. Google Scholar

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