5-Amino-1-(2-hydroxy­ethyl)-1H-pyrazole

The title compound, C₅H₉ON₃, was synthesized by the reaction of 2-hydrazinylethanol with 3-methoxy­propane­nitrile. The pyrazole ring system is essentially planar. Molecules are linked by O—H...N and N—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.032
• wR factor = 0.087
• Data-to-parameter ratio = 11.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT150_ALERT_1_C Volume as Calculated Differs from that Given ...     619.70 Ang-3
PLAT420_ALERT_2_C D-H Without Acceptor       N3     -   H3B    ...          ?
PLAT480_ALERT_4_C Long H...A H-Bond Reported H3A    ..  O1      ..       2.61 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

5-Amino-1-(2-hydroxyethyl)pyrazole

Crystal data

C5H9N3O	F(000) = 272
Mr = 127.15	Dx = 1.363 Mg m^−3
Monoclinic, P21/n	Melting point = 379–381 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 8.977 (2) Å	Cell parameters from 1169 reflections
b = 5.5467 (14) Å	θ = 4.0–24.7°
c = 12.562 (3) Å	µ = 0.10 mm^−1
β = 97.774 (4)°	T = 294 K
V = 619.7 (3) Å^3	Rod, colourless
Z = 4	0.22 × 0.20 × 0.12 mm

Data collection

Bruker SMART 1000 diffractometer	1094 independent reflections
Radiation source: fine-focus sealed tube	853 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 25.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −9→10
Tmin = 0.978, Tmax = 0.988	k = −6→6
3003 measured reflections	l = −14→8

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.032	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.087	w = 1/[σ^2(Fo^2) + (0.0417P)^2 + 0.0839P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
1094 reflections	Δρmax = 0.15 e Å^−3
94 parameters	Δρmin = −0.17 e Å^−3
3 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.045 (6)

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

	x	y	z	Uiso*/Ueq
O1	0.17221 (12)	0.1734 (2)	0.58285 (9)	0.0529 (4)
H1	0.2487 (19)	0.096 (4)	0.5984 (15)	0.079*
N1	0.00693 (13)	0.3657 (2)	0.74470 (9)	0.0350 (4)
N2	0.05615 (14)	0.4198 (2)	0.85014 (9)	0.0394 (4)
N3	−0.15422 (17)	0.0992 (3)	0.63531 (12)	0.0461 (4)
C1	0.19681 (17)	0.4116 (3)	0.62165 (12)	0.0448 (5)
H1A	0.2253	0.5138	0.5651	0.054*
H1B	0.2781	0.4129	0.6810	0.054*
C2	0.05562 (17)	0.5066 (3)	0.65862 (11)	0.0398 (4)
H2A	0.0726	0.6716	0.6829	0.048*
H2B	−0.0240	0.5084	0.5982	0.048*
C3	−0.08801 (15)	0.1754 (3)	0.73550 (12)	0.0345 (4)
C4	−0.10492 (17)	0.1050 (3)	0.83809 (12)	0.0406 (4)
H4	−0.1642	−0.0199	0.8584	0.049*
C5	−0.01432 (17)	0.2606 (3)	0.90483 (12)	0.0410 (4)
H5	−0.0040	0.2544	0.9794	0.049*
H3A	−0.0928 (18)	0.083 (3)	0.5894 (13)	0.057 (6)*
H3B	−0.2097 (19)	−0.030 (3)	0.6385 (14)	0.062 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0387 (7)	0.0626 (9)	0.0566 (8)	0.0053 (6)	0.0035 (6)	−0.0139 (6)
N1	0.0380 (7)	0.0355 (7)	0.0310 (7)	0.0002 (6)	0.0024 (5)	−0.0010 (5)
N2	0.0440 (8)	0.0398 (8)	0.0329 (7)	−0.0002 (6)	−0.0001 (6)	−0.0024 (6)
N3	0.0441 (9)	0.0466 (9)	0.0464 (9)	−0.0046 (7)	0.0020 (7)	−0.0106 (7)
C1	0.0383 (9)	0.0542 (11)	0.0411 (9)	−0.0081 (8)	0.0022 (7)	0.0044 (8)
C2	0.0456 (10)	0.0369 (9)	0.0357 (9)	−0.0006 (7)	0.0004 (7)	0.0046 (7)
C3	0.0295 (8)	0.0329 (8)	0.0405 (9)	0.0027 (6)	0.0028 (6)	−0.0046 (6)
C4	0.0364 (9)	0.0390 (9)	0.0475 (10)	−0.0018 (7)	0.0097 (7)	0.0041 (7)
C5	0.0436 (9)	0.0455 (10)	0.0344 (8)	0.0057 (8)	0.0069 (7)	0.0024 (7)

Geometric parameters (Å, º)

O1—C1	1.415 (2)	C1—C2	1.503 (2)
O1—H1	0.810 (15)	C1—H1A	0.9700
N1—C3	1.3516 (19)	C1—H1B	0.9700
N1—N2	1.3717 (16)	C2—H2A	0.9700
N1—C2	1.4490 (18)	C2—H2B	0.9700
N2—C5	1.330 (2)	C3—C4	1.375 (2)
N3—C3	1.3834 (19)	C4—C5	1.388 (2)
N3—H3A	0.855 (14)	C4—H4	0.9300
N3—H3B	0.877 (14)	C5—H5	0.9300
C1—O1—H1	108.7 (15)	N1—C2—H2A	108.9
C3—N1—N2	111.74 (12)	C1—C2—H2A	108.9
C3—N1—C2	127.44 (12)	N1—C2—H2B	108.9
N2—N1—C2	120.82 (12)	C1—C2—H2B	108.9
C5—N2—N1	103.89 (12)	H2A—C2—H2B	107.8
C3—N3—H3A	114.1 (12)	N1—C3—C4	106.87 (13)
C3—N3—H3B	112.6 (12)	N1—C3—N3	120.32 (14)
H3A—N3—H3B	111.5 (17)	C4—C3—N3	132.67 (15)
O1—C1—C2	109.57 (13)	C3—C4—C5	105.04 (13)
O1—C1—H1A	109.8	C3—C4—H4	127.5
C2—C1—H1A	109.8	C5—C4—H4	127.5
O1—C1—H1B	109.8	N2—C5—C4	112.44 (14)
C2—C1—H1B	109.8	N2—C5—H5	123.8
H1A—C1—H1B	108.2	C4—C5—H5	123.8
N1—C2—C1	113.16 (13)
C3—N1—N2—C5	−1.41 (15)	N2—N1—C3—N3	177.53 (13)
C2—N1—N2—C5	178.07 (13)	C2—N1—C3—N3	−1.9 (2)
C3—N1—C2—C1	−90.70 (18)	N1—C3—C4—C5	−0.82 (17)
N2—N1—C2—C1	89.90 (16)	N3—C3—C4—C5	−176.24 (16)
O1—C1—C2—N1	60.44 (17)	N1—N2—C5—C4	0.86 (16)
N2—N1—C3—C4	1.43 (16)	C3—C4—C5—N2	−0.04 (18)
C2—N1—C3—C4	−178.01 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N2^i	0.81 (2)	2.04 (2)	2.8422 (18)	175 (2)
N3—H3A···O1^ii	0.86 (1)	2.61 (2)	3.1149 (19)	119 (1)
N3—H3A···O1	0.86 (1)	2.44 (2)	3.117 (2)	136 (2)

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