Ethyl 5-amino-3-methyl­sulfan­yl-1H-pyrazole-4-carboxyl­ate

In the title compound, C₇H₁₁N₃O₂S, bond lengths and angles are within normal ranges. The crystal packing is stabilized by inter­molecular N—H...O hydrogen bonds, linking the mol­ecules into infinite one-dimensional chains along the a axis.

Key indicators

• Single-crystal X-ray study
• T = 273 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.044
• wR factor = 0.127
• Data-to-parameter ratio = 13.8

checkCIF/PLATON results

No syntax errors found



Alert level C
            Value of measurement temperature given =   273.000
            Value of melting point given =     0.000
PLAT230_ALERT_2_C Hirshfeld Test Diff for    S1     --  C6      ..       5.80 su
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.19
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 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
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title compound, is an important intermediate in synthesis of heterocyclic compounds (Hanfeld et al., 1996) in particular, in producing imidazo[1,2-b]pyrazole derivatives. Here, we report the crystal structure of (I).

In compound (I), all bond lengths and angles are normal and in a good agreement with those reported previously (Ren et al., 2004). The pyrazole ring C4/C5/C5/N2/N3 and bonded atoms N1, S1, C3, O1, C2 and C1 are coplanar, the largest deviation from the mean plane being 0.053 (2)Å for atom C3. The crystal packing is stabilized by intermolecular N—H···O hydrogen bonds, linking the molecules into infinite one-dimensional chain along the a axis.

Related literature

For the biological activity, see: Hanfeld et al. (1996). For a similar structure, see: Ren et al. (2004).

S2. Experimental

A round-bottomed flask fitted with a dropping funnel was charged with 11.2 g (0.2 mol) potassium hydroxide in 200 ml MeCN. The solution was cooled in an ice bath. Through the dropping funnel 22.7 g (0.2 mol) ethyl cyanoacetate was added gradually. After stirring at 273K for 0.5 h, 15.2 g(0.2 mol) carbon bisulfide was added while vigorous stirring. Keep stirring for 1 h, 50.4 g(0.4 mol) dimethyl sulfate was added through the drop funnel, then left overnight. The reaction mixture was filtered and filtrate evaporated on a rotary evaporator to remove the solvent. The mixture was dissolved in 50 ml ethanol, then through a drop funnel 12.5 g (0.2 mol) of hydrazine hydrate was added. The solution was evaporated in vacuo to afford crude product, which was purified by column chromatography to give the desired product 34.7 g, yield 86.3%. Crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of a methanol solution at room temperature for one week.

S3. Refinement

All H atoms were placed in calculated positions, with C—H = 0.93 or 0.97 Å, N–H = 0.86 Å, and included in the final cycles of refinement using a riding model, with U_iso(H) = 1.2 (1.5 times for methyl) times U_eq(C,N).

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. View of the title compound (I), with displacement ellipsoids drawn at the 40% probability level.

Ethyl 5-amino-3-methylsulfanyl-1H-pyrazole-4-carboxylate

Crystal data

C7H11N3O2S	Z = 2
Mr = 201.25	F(000) = 212
Triclinic, P1	Dx = 1.437 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.0012 (7) Å	Cell parameters from 1750 reflections
b = 7.5870 (8) Å	θ = 3.0–27.5°
c = 10.1055 (10) Å	µ = 0.32 mm^−1
α = 81.038 (2)°	T = 273 K
β = 72.173 (2)°	Block, yellow
γ = 65.643 (1)°	0.10 × 0.10 × 0.05 mm
V = 465.26 (8) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	1624 independent reflections
Radiation source: fine-focus sealed tube	1488 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.013
ϕ and ω scans	θmax = 25.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→8
Tmin = 0.969, Tmax = 0.984	k = −8→9
2317 measured reflections	l = −5→11

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.127	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0669P)^2 + 0.2967P] where P = (Fo^2 + 2Fc^2)/3
1624 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

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.

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 (Ų)

	x	y	z	Uiso*/Ueq
S1	0.46271 (10)	0.72168 (10)	0.13781 (7)	0.0506 (3)
O1	0.3262 (3)	0.7811 (3)	0.61242 (17)	0.0461 (4)
O2	0.1914 (3)	0.7558 (3)	0.44317 (18)	0.0486 (5)
N2	0.8938 (3)	0.7010 (3)	0.3056 (2)	0.0435 (5)
H2C	1.0232	0.6889	0.3013	0.052*
C3	0.3414 (4)	0.7574 (3)	0.4801 (2)	0.0383 (5)
N1	0.7639 (3)	0.7355 (3)	0.5482 (2)	0.0510 (6)
H1D	0.8881	0.7260	0.5535	0.061*
H1E	0.6578	0.7515	0.6223	0.061*
C5	0.7355 (3)	0.7256 (3)	0.4242 (2)	0.0368 (5)
C2	0.1246 (4)	0.8045 (4)	0.7109 (3)	0.0418 (6)
H2A	0.0903	0.6923	0.7138	0.050*
H2B	0.0088	0.9182	0.6866	0.050*
C6	0.6221 (4)	0.7165 (3)	0.2425 (3)	0.0387 (5)
N3	0.8282 (3)	0.6970 (3)	0.1904 (2)	0.0450 (5)
C4	0.5518 (3)	0.7352 (3)	0.3906 (2)	0.0360 (5)
C1	0.1484 (5)	0.8274 (4)	0.8514 (3)	0.0542 (7)
H1A	0.0146	0.8433	0.9215	0.081*
H1B	0.1818	0.9392	0.8472	0.081*
H1C	0.2638	0.7143	0.8740	0.081*
C7	0.6528 (5)	0.7014 (5)	−0.0316 (3)	0.0626 (8)
H7A	0.5843	0.7025	−0.1009	0.094*
H7B	0.7777	0.5824	−0.0347	0.094*
H7C	0.6977	0.8085	−0.0493	0.094*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0384 (4)	0.0712 (5)	0.0510 (4)	−0.0245 (3)	−0.0179 (3)	−0.0052 (3)
O1	0.0381 (9)	0.0649 (11)	0.0429 (9)	−0.0248 (8)	−0.0141 (7)	−0.0026 (8)
O2	0.0306 (9)	0.0707 (12)	0.0543 (11)	−0.0249 (8)	−0.0170 (8)	−0.0035 (9)
N2	0.0280 (9)	0.0626 (13)	0.0486 (12)	−0.0232 (9)	−0.0139 (8)	−0.0029 (9)
C3	0.0304 (11)	0.0412 (12)	0.0469 (13)	−0.0150 (9)	−0.0144 (10)	0.0001 (10)
N1	0.0336 (11)	0.0840 (16)	0.0477 (12)	−0.0301 (11)	−0.0154 (9)	−0.0060 (11)
C5	0.0286 (11)	0.0430 (12)	0.0450 (12)	−0.0174 (9)	−0.0143 (9)	−0.0002 (10)
C2	0.0311 (11)	0.0468 (13)	0.0547 (14)	−0.0174 (10)	−0.0189 (10)	−0.0003 (11)
C6	0.0324 (11)	0.0389 (12)	0.0460 (13)	−0.0151 (9)	−0.0100 (10)	−0.0022 (9)
N3	0.0335 (10)	0.0597 (13)	0.0463 (12)	−0.0218 (9)	−0.0105 (9)	−0.0043 (9)
C4	0.0254 (10)	0.0398 (11)	0.0475 (13)	−0.0141 (9)	−0.0141 (9)	−0.0016 (9)
C1	0.0513 (15)	0.0736 (18)	0.0446 (14)	−0.0320 (14)	−0.0093 (12)	−0.0064 (13)
C7	0.0547 (17)	0.095 (2)	0.0483 (16)	−0.0347 (16)	−0.0180 (13)	−0.0050 (15)

Geometric parameters (Å, º)

S1—C6	1.744 (2)	C5—C4	1.399 (3)
S1—C7	1.801 (3)	C2—C1	1.522 (3)
O1—C3	1.343 (3)	C2—H2A	0.9700
O1—C2	1.415 (3)	C2—H2B	0.9700
O2—C3	1.222 (3)	C6—N3	1.328 (3)
N2—C5	1.336 (3)	C6—C4	1.435 (3)
N2—N3	1.385 (3)	C1—H1A	0.9600
N2—H2C	0.8600	C1—H1B	0.9600
C3—C4	1.429 (3)	C1—H1C	0.9600
N1—C5	1.346 (3)	C7—H7A	0.9600
N1—H1D	0.8600	C7—H7B	0.9600
N1—H1E	0.8600	C7—H7C	0.9600
C6—S1—C7	100.66 (12)	N3—C6—C4	111.9 (2)
C3—O1—C2	116.79 (18)	N3—C6—S1	122.18 (19)
C5—N2—N3	113.11 (18)	C4—C6—S1	125.90 (17)
C5—N2—H2C	123.4	C6—N3—N2	104.02 (19)
N3—N2—H2C	123.4	C5—C4—C3	129.2 (2)
O2—C3—O1	123.1 (2)	C5—C4—C6	103.93 (19)
O2—C3—C4	125.2 (2)	C3—C4—C6	126.9 (2)
O1—C3—C4	111.67 (19)	C2—C1—H1A	109.5
C5—N1—H1D	120.0	C2—C1—H1B	109.5
C5—N1—H1E	120.0	H1A—C1—H1B	109.5
H1D—N1—H1E	120.0	C2—C1—H1C	109.5
N2—C5—N1	122.8 (2)	H1A—C1—H1C	109.5
N2—C5—C4	107.0 (2)	H1B—C1—H1C	109.5
N1—C5—C4	130.2 (2)	S1—C7—H7A	109.5
O1—C2—C1	106.85 (18)	S1—C7—H7B	109.5
O1—C2—H2A	110.4	H7A—C7—H7B	109.5
C1—C2—H2A	110.4	S1—C7—H7C	109.5
O1—C2—H2B	110.4	H7A—C7—H7C	109.5
C1—C2—H2B	110.4	H7B—C7—H7C	109.5
H2A—C2—H2B	108.6
C2—O1—C3—O2	0.2 (3)	N1—C5—C4—C3	−0.4 (4)
C2—O1—C3—C4	−179.98 (19)	N2—C5—C4—C6	−0.8 (2)
N3—N2—C5—N1	−179.3 (2)	N1—C5—C4—C6	179.9 (2)
N3—N2—C5—C4	1.3 (3)	O2—C3—C4—C5	−176.5 (2)
C3—O1—C2—C1	179.7 (2)	O1—C3—C4—C5	3.6 (3)
C7—S1—C6—N3	−1.3 (2)	O2—C3—C4—C6	3.1 (4)
C7—S1—C6—C4	177.5 (2)	O1—C3—C4—C6	−176.7 (2)
C4—C6—N3—N2	0.6 (3)	N3—C6—C4—C5	0.1 (3)
S1—C6—N3—N2	179.63 (16)	S1—C6—C4—C5	−178.88 (17)
C5—N2—N3—C6	−1.2 (3)	N3—C6—C4—C3	−179.6 (2)
N2—C5—C4—C3	178.9 (2)	S1—C6—C4—C3	1.4 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1D···O2^i	0.86	2.16	2.914 (3)	146
N2—H2C···O2^i	0.86	2.34	3.019 (3)	137

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