4-Formyl-3-p-tolyl­sydnone

In the title compound, C₁₀H₈N₂O₃, the oxadiazole ring is essentially planar, with a maximum deviation of 0.006 (1) Å for the two-connected N atom. The mean planes through the aldehyde unit and the methyl-substituted phenyl ring make inter­planar angles of 13.60 (9) and 59.69 (4)°, respectively, with the oxadiazole ring. In the crystal structure, adjacent mol­ecules are inter­connected into a two-dimensional array parallel to (100) by inter­molecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.001 Å
• R factor = 0.042
• wR factor = 0.132
• Data-to-parameter ratio = 35.8

checkCIF/PLATON results

No syntax errors found



Alert level C
DIFMX01_ALERT_2_C  The maximum difference density is > 0.1*ZMAX*0.75
            _refine_diff_density_max given =      0.645
            Test value =      0.600
DIFMX02_ALERT_1_C  The maximum difference density is > 0.1*ZMAX*0.75
            The relevant atom site should be identified.
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.06
PLAT097_ALERT_2_C Large Reported Max.  (Positive) Residual Density       0.64 eA-3
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C7     --  C8      ..       5.16 su
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         25
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          5

Alert level G
PLAT960_ALERT_3_G Number of Intensities with I .LT. - 2*sig(I) ..           2
PLAT063_ALERT_4_G Crystal Size Likely too Large for Beam Size ....       0.71 mm

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

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

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S1. Comment

Sydnones constitute a well-defined class of mesoionic compounds consisting of 1,2,3-oxadiazole ring system. The introduction of the concept of mesoionic structure for certain heterocyclic compounds in the year 1949 has proved to be fruitful development in heterocyclic chemistry. The study of sydnones still remains a field of interest because of their electronic structure and also because of the various types of biological activities displayed by some of them. Interest in sydnone derivatives has also been encouraged by the discovery that they exhibit various pharmacological activities (Hedge et al., 2008; Rai et al., 2008).

These 4-formyl sydnone will be used for the preparation of a new series of α,β-unsaturated carbonyl compounds (namely chalcones) by condensation with appropriate ketones or aldehydes. These α,β-unsaturated carbonyl compounds will be utilized for the synthesis of a variety of novel heterocyclic compounds like pyrazolines, pyrazole etc carrying sydnone moiety.

Sydnones are mesoionic compounds containing a five-membered heterocyclic ring. Generally, substitution at the N3 position by an aromatic substituent is necessary for stability. In the title sydnone compound (Fig. 1), the aromatic substituent is p-toluene. The 1,2,3-oxadiazole ring (N1/N2/O1/C7/C8) in the sydnone unit is essentially planar, with maximum deviation of -0.006 (1) Å at atom N2. The mean planes through the aldehyde moiety (C9/H9A/O3) and methyl-substituted phenyl ring (C1-C6) are inclined at dihedral angles of 13.60 (9) and 59.69 (4)°, respectively, with the 1,2,3-oxadiazole ring. As reported previously (Grossie et al., 2009), the exocyclic C7–O2 bond length of 1.2089 (9) Å is inconsistent to the formulation of Baker & Ollis (1957), which reported the delocalization of a positive charge in the ring, and a negative charge in the exocyclic oxygen. The bond lengths (Allen et al., 1987) and angles are within normal range and comparable to a related sydnone structure (Grossie et al., 2009). In the crystal structure (Fig. 2), intermolecular C1—H1A···O2 and C5—H5A···O3 hydrogen bonds (Table 1) link adjacent molecules into two-dimensional arrays parallel to the (100) plane.

Related literature

For general background to and applications of sydnone compounds, see: Hedge et al. (2008); Rai et al. (2008). For related sydnone structures, see: Baker & Ollis (1957); Grossie et al. (2009). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986). For bond-length data, see: Allen et al. (1987).

S2. Experimental

N-Methylformanilide (0.01 mol) and phosphoryl chloride (0.01 mol) were mixed and added into 3-(p-tolyl)sydnone (0.01 mol) portion-wise. The reaction mixture was then stirred for about 1 h under cold condition. After standing overnight, it was poured into ice cold water with stirring. The solid obtained was filtered, dried and recrystallized from ethanol. Single crystals suitable for X-ray analysis were obtained from a 1:2 mixture of DMF and ethanol by slow evaporation.

S3. Refinement

All hydrogen atoms were placed in their calculated positions, with C—H = 0.93 or 0.96 Å, and refined using a riding model with U_iso = 1.2 or 1.5 U_eq(C). A rotating group model was used for the C10 methyl group.

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids for non-H atoms and the atom-numbering scheme.
	Fig. 2. The crystal structure of the title compound, viewed along the a axis, showing a two-dimensional array parallel to the (100) plane. Hydrogen atoms not involved in intermolecular interactions (dashed lines) have been omitted for clarity.

4-Formyl-3-p-tolylsydnone

Crystal data

C10H8N2O3	F(000) = 424
Mr = 204.18	Dx = 1.448 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6788 reflections
a = 10.5663 (4) Å	θ = 2.8–38.9°
b = 10.4088 (3) Å	µ = 0.11 mm^−1
c = 8.9630 (3) Å	T = 100 K
β = 108.222 (1)°	Block, brown
V = 936.34 (5) Å^3	0.71 × 0.30 × 0.19 mm
Z = 4

Data collection

Bruker APEXII DUO CCD area-detector diffractometer	4906 independent reflections
Radiation source: fine-focus sealed tube	4091 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
φ and ω scans	θmax = 37.5°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −18→18
Tmin = 0.926, Tmax = 0.980	k = −17→17
14437 measured reflections	l = −15→14

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.132	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0747P)^2 + 0.1421P] where P = (Fo^2 + 2Fc^2)/3
4906 reflections	(Δ/σ)max = 0.001
137 parameters	Δρmax = 0.65 e Å^−3
0 restraints	Δρmin = −0.31 e Å^−3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.

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
O1	0.34006 (6)	0.22147 (5)	0.96639 (6)	0.01912 (11)
O2	0.26550 (6)	0.39559 (5)	1.06918 (7)	0.02245 (12)
O3	0.53489 (6)	0.55203 (5)	1.23353 (7)	0.02190 (12)
N1	0.54958 (6)	0.24689 (5)	1.05402 (6)	0.01524 (10)
N2	0.45929 (7)	0.17063 (6)	0.96707 (7)	0.01825 (11)
C1	0.76823 (8)	0.30000 (7)	1.03217 (9)	0.02080 (13)
H1A	0.7346	0.3773	0.9839	0.025*
C2	0.90126 (8)	0.26687 (7)	1.05976 (10)	0.02297 (14)
H2A	0.9571	0.3228	1.0289	0.028*
C3	0.95243 (8)	0.15115 (7)	1.13297 (9)	0.02082 (13)
C4	0.86671 (8)	0.06713 (7)	1.17625 (9)	0.02117 (13)
H4A	0.8996	−0.0106	1.2238	0.025*
C5	0.73342 (8)	0.09745 (6)	1.14961 (8)	0.01803 (12)
H5A	0.6768	0.0411	1.1783	0.022*
C6	0.68736 (7)	0.21424 (6)	1.07890 (7)	0.01561 (11)
C7	0.35989 (7)	0.33640 (6)	1.05605 (8)	0.01719 (12)
C8	0.50088 (7)	0.34990 (6)	1.11215 (8)	0.01566 (11)
C9	0.58136 (8)	0.44999 (6)	1.20780 (8)	0.01744 (12)
H9A	0.6724	0.4362	1.2517	0.021*
C10	1.09685 (9)	0.11710 (10)	1.16471 (12)	0.03014 (17)
H10D	1.1460	0.1928	1.1562	0.045*
H10A	1.1048	0.0545	1.0895	0.045*
H10B	1.1319	0.0823	1.2687	0.045*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0194 (2)	0.0159 (2)	0.0216 (2)	0.00027 (17)	0.00558 (19)	−0.00320 (16)
O2	0.0212 (3)	0.0188 (2)	0.0285 (3)	0.00347 (18)	0.0094 (2)	−0.00196 (18)
O3	0.0306 (3)	0.0144 (2)	0.0250 (2)	−0.00230 (19)	0.0148 (2)	−0.00363 (17)
N1	0.0194 (3)	0.01228 (19)	0.0155 (2)	−0.00027 (17)	0.00755 (19)	−0.00047 (15)
N2	0.0206 (3)	0.0153 (2)	0.0194 (2)	−0.00021 (19)	0.0070 (2)	−0.00313 (17)
C1	0.0255 (3)	0.0152 (2)	0.0263 (3)	−0.0009 (2)	0.0148 (3)	0.0028 (2)
C2	0.0243 (3)	0.0202 (3)	0.0294 (3)	−0.0039 (2)	0.0157 (3)	−0.0007 (2)
C3	0.0195 (3)	0.0230 (3)	0.0216 (3)	−0.0007 (2)	0.0089 (2)	−0.0034 (2)
C4	0.0220 (3)	0.0192 (3)	0.0237 (3)	0.0025 (2)	0.0091 (3)	0.0025 (2)
C5	0.0207 (3)	0.0143 (2)	0.0211 (3)	0.0000 (2)	0.0095 (2)	0.00184 (19)
C6	0.0186 (3)	0.0133 (2)	0.0172 (2)	−0.00044 (19)	0.0088 (2)	−0.00029 (17)
C7	0.0210 (3)	0.0134 (2)	0.0179 (2)	0.0007 (2)	0.0072 (2)	−0.00046 (18)
C8	0.0195 (3)	0.0127 (2)	0.0166 (2)	0.0000 (2)	0.0083 (2)	−0.00152 (17)
C9	0.0220 (3)	0.0149 (2)	0.0178 (2)	−0.0033 (2)	0.0097 (2)	−0.00218 (19)
C10	0.0195 (3)	0.0387 (4)	0.0328 (4)	0.0012 (3)	0.0091 (3)	−0.0044 (3)

Geometric parameters (Å, º)

O1—N2	1.3647 (8)	C3—C4	1.3983 (11)
O1—C7	1.4197 (8)	C3—C10	1.5046 (12)
O2—C7	1.2089 (9)	C4—C5	1.3893 (11)
O3—C9	1.2220 (9)	C4—H4A	0.9300
N1—N2	1.2971 (8)	C5—C6	1.3870 (9)
N1—C8	1.3615 (8)	C5—H5A	0.9300
N1—C6	1.4428 (9)	C7—C8	1.4225 (10)
C1—C6	1.3878 (9)	C8—C9	1.4448 (9)
C1—C2	1.3924 (11)	C9—H9A	0.9300
C1—H1A	0.9300	C10—H10D	0.9600
C2—C3	1.3971 (11)	C10—H10A	0.9600
C2—H2A	0.9300	C10—H10B	0.9600
N2—O1—C7	110.58 (5)	C4—C5—H5A	121.0
N2—N1—C8	114.64 (6)	C5—C6—C1	122.72 (7)
N2—N1—C6	117.76 (5)	C5—C6—N1	118.03 (6)
C8—N1—C6	127.60 (6)	C1—C6—N1	119.25 (6)
N1—N2—O1	105.66 (5)	O2—C7—O1	120.29 (7)
C6—C1—C2	118.02 (7)	O2—C7—C8	136.05 (6)
C6—C1—H1A	121.0	O1—C7—C8	103.66 (5)
C2—C1—H1A	121.0	N1—C8—C7	105.44 (6)
C1—C2—C3	121.19 (7)	N1—C8—C9	124.90 (6)
C1—C2—H2A	119.4	C7—C8—C9	129.64 (6)
C3—C2—H2A	119.4	O3—C9—C8	122.82 (7)
C2—C3—C4	118.71 (7)	O3—C9—H9A	118.6
C2—C3—C10	120.83 (7)	C8—C9—H9A	118.6
C4—C3—C10	120.45 (7)	C3—C10—H10D	109.5
C5—C4—C3	121.34 (7)	C3—C10—H10A	109.5
C5—C4—H4A	119.3	H10D—C10—H10A	109.5
C3—C4—H4A	119.3	C3—C10—H10B	109.5
C6—C5—C4	118.01 (6)	H10D—C10—H10B	109.5
C6—C5—H5A	121.0	H10A—C10—H10B	109.5
C8—N1—N2—O1	−1.23 (7)	N2—N1—C6—C1	120.44 (7)
C6—N1—N2—O1	178.51 (5)	C8—N1—C6—C1	−59.85 (9)
C7—O1—N2—N1	1.09 (7)	N2—O1—C7—O2	179.97 (6)
C6—C1—C2—C3	−0.31 (11)	N2—O1—C7—C8	−0.58 (7)
C1—C2—C3—C4	1.07 (12)	N2—N1—C8—C7	0.88 (7)
C1—C2—C3—C10	−178.99 (8)	C6—N1—C8—C7	−178.84 (6)
C2—C3—C4—C5	−0.81 (11)	N2—N1—C8—C9	−178.07 (6)
C10—C3—C4—C5	179.25 (7)	C6—N1—C8—C9	2.22 (10)
C3—C4—C5—C6	−0.19 (11)	O2—C7—C8—N1	179.18 (8)
C4—C5—C6—C1	1.01 (11)	O1—C7—C8—N1	−0.13 (7)
C4—C5—C6—N1	−178.80 (6)	O2—C7—C8—C9	−1.94 (13)
C2—C1—C6—C5	−0.76 (11)	O1—C7—C8—C9	178.74 (6)
C2—C1—C6—N1	179.05 (6)	N1—C8—C9—O3	166.06 (6)
N2—N1—C6—C5	−59.74 (8)	C7—C8—C9—O3	−12.62 (11)
C8—N1—C6—C5	119.96 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1A···O2^i	0.93	2.41	3.2847 (9)	156
C5—H5A···O3^ii	0.93	2.60	3.3489 (11)	138

Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, y−1/2, −z+5/2.