2-(4-Chloro­phen­oxy)acetohydrazide

In the title compound, C₈H₉ClN₂O₂, the two planar fragments, i.e. the chloro­phenyl and C—C(=O)—N groups, are inclined at 14.93 (17)°. In the crystal, relatively weak inter­molecular N—H...N, C—H...O and N—H...O hydrogen bonds connect the mol­ecules into layers. The hydro­phobic parts of mol­ecules stick outside these layers and are connected with the neighbouring layers only by van der Waals contacts and Cl...Cl inter­actions [3.406 (2) Å].

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.058
• wR factor = 0.118
• Data-to-parameter ratio = 11.4

checkCIF/PLATON results

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Alert level C
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low ....       0.90
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600        160

   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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 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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S1. Comment

Hydrazides are useful precursors in the synthesis of several heterocyclic systems (e.g., Narayana et al., 2005). Some substituted hydrazides are reported to exhibit carcinostatic activity against several types of tumors and also possess antimicrobial activity (e.g., Cajocorius et al., 1977). They are also used as intermediates in many pharmaceutically important compounds (Liu et al., 2006). A new hydrazide, 2-(4-chlorophenoxy)acetohydrazide (I, Scheme 1), C₈H₉ClN₂O₂ was synthesized and its crystal structure is reported.

The molecule of I consists of two planar fragments (Fig. 1): the phenyl ring [maximum deviation of 0.014 (2) Å] and the N—C(=O)—C group, which is planar within 0.008 (2) Å. The N1 and O6 atoms deviate significantly (by ca 0.11 Å), and in the opposite directions, from this latter plane. Overall, the molecule is only slightly bent as the dihedral angle between the planes described above is 14.93 (17)°. Even smaller values of this angle were observed in similar compounds: 5.0° in [2-methyl-4-(2-methylbenzoyl)-phenoxy]acetohydrazide (Mahendra et al., 2004), 3.6° in (2,4-dichlorophenoxy)acetohydrazide (Lokanath et al., 1998) or 5.7° in 4-tert-butylphenoxyacetohydrazide (Podyachev et al., 2007). This planar and (Z)-NCCO conformation was sometimes ascribed to the doubtful intramolecular N—H···O hydrogen bond. When the steric hindrance is present, as for instance in the structure of 2-(4-bromophenoxy)propanohydrazide (Akhtar et al., 2009), the two planar fragments become almost perpendicular, dihedral angle between them is 84.9°.

In the crystal structure rather long intermolecular hydrogen bonds connect molecules into three-dimensional network (Table 1). The N—H···N hydrogen bonds, for which the terminal nitrogen atom of NH₂ group acts as an acceptor, make a C(3) graph-set motif (Bernstein et al., 1995) - the chain of molecules along the b axis. Two N—H···O hydrogen bonds between the NH₂ group and carbonyl oxygen atoms from neighbouring molecules make antiparallel C(5) chains that are interwoven into subsequent R²₂(10) rings. In the crystal structure there are layers of molecules connected by these hydrogen bonded hydrophilic fragments and the hydrophobic chlorophenyl fragments stick outside the layers. There are relatively short and linear Cl···Cl contacts between these layers [Cl13···Cl13(3 - x,-1 - y,1 - z) 3.406 (2) Å, C10—Cl13···Cl13(3 - x,-1 - y,1 - z) 155.14 (13)°], suggesting that there is a possibility for "dihalogen" interactions (e.g. Pedireddi et al., 1994).

Related literature

For background to hydrazides, see: Cajocorius et al. (1977); Liu et al. (2006); Narayana et al. (2005). For related structures, see: Akhtar et al. (2009); Lokanath et al. (1998); Mahendra et al. (2004); Podyachev et al. (2007). For graph-set symbols, see: Bernstein et al. (1995). For halogen–halogen interactions, see: Pedireddi et al. (1994).

S2. Experimental

A mixture of ethyl(4-chlorophenoxy)acetate (21.4 g, 0.1 mol) and 6.0 ml of hydrazine hydrate in 90 ml of ethanol was refluxed over water bath for 6 h. The precipitate formed was filtered and recrystallized from ethanol (m.p.: 425 K). Analysis for C₈H₉ClN₂O₂: Found (Calculated): C 47.89 (47.81), H 4.52 (4.48), N 13.96% (13.88%).

S3. Refinement

All hydrogen atoms were freely refined.

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Anisotropic ellipsoid representation of the compound I together with atom labelling scheme. The ellipsoids are drawn at the 50% probability level and hydrogen atoms are depicted as spheres with arbitrary radii.
	Fig. 2. The hydrogen bonded motifs in the crystal structure of I. Hydrogen bonds are shown as dashed lines. (a) the N—H···N chain. [Symmetry codes: (i) x, y, z; (ii) x, -3/2 + y, 3/2 - z; (iii) 2 - x, 1/2 + y, 3/2 - z; (iv) 2 - x, -1/2 + y, 3/2 - z; (v) 2 - x, -3/2 + y, 3/2 - z.] (b) the N—H···O chains and rings. [Symmetry codes: (i) x, y, z; (ii) 1 - x, 1/2 + y, 3/2 - z; (iii) 1 - x, -1/2 + y, 3/2 - z.]
	Fig. 3. Crystal packing as seen along the a axis. Hydrogen bonds and Cl···Cl contacts are shown as dashed lines.

2-(4-Chlorophenoxy)acetohydrazide

Crystal data

C8H9ClN2O2	F(000) = 416
Mr = 200.62	Dx = 1.458 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1266 reflections
a = 6.444 (1) Å	θ = 2.3–26.8°
b = 4.011 (1) Å	µ = 0.39 mm^−1
c = 35.369 (4) Å	T = 295 K
β = 91.89 (1)°	Plate, colourless
V = 913.7 (3) Å^3	0.4 × 0.4 × 0.15 mm
Z = 4

Data collection

Oxford Diffraction Xcalibur (Sapphire2, large Be window) diffractometer	1761 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1448 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
Detector resolution: 8.1929 pixels mm^-1	θmax = 26.8°, θmin = 2.3°
ω–scan	h = −8→6
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −3→4
Tmin = 0.678, Tmax = 0.944	l = −31→43
2864 measured reflections

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)] = 0.058	Hydrogen site location: difference Fourier map
wR(F^2) = 0.118	All H-atom parameters refined
S = 1.15	w = 1/[σ^2(Fo^2) + (0.0271P)^2 + 1.1206P] where P = (Fo^2 + 2Fc^2)/3
1761 reflections	(Δ/σ)max = 0.002
154 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.28 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
N1	0.7883 (4)	0.5362 (7)	0.75916 (7)	0.0346 (6)
H1A	0.717 (5)	0.733 (11)	0.7541 (10)	0.066 (11)*
H1B	0.711 (5)	0.417 (9)	0.7747 (9)	0.054 (10)*
N2	0.8013 (3)	0.3650 (6)	0.72417 (6)	0.0317 (5)
H2	0.909 (4)	0.247 (8)	0.7201 (8)	0.039 (8)*
C3	0.6568 (4)	0.4000 (7)	0.69716 (7)	0.0300 (6)
O4	0.4957 (3)	0.5630 (6)	0.70086 (5)	0.0425 (5)
C5	0.6937 (4)	0.2401 (8)	0.65965 (8)	0.0341 (6)
H5A	0.573 (5)	0.103 (8)	0.6525 (8)	0.047 (9)*
H5B	0.709 (4)	0.412 (8)	0.6420 (8)	0.043 (8)*
O6	0.8781 (3)	0.0467 (5)	0.66140 (5)	0.0398 (5)
C7	0.9615 (4)	−0.0520 (8)	0.62801 (7)	0.0342 (6)
C8	1.1514 (4)	−0.2151 (8)	0.63137 (8)	0.0412 (7)
H8	1.213 (5)	−0.241 (8)	0.6556 (8)	0.050 (9)*
C9	1.2501 (5)	−0.3162 (9)	0.59971 (9)	0.0478 (8)
H9	1.374 (5)	−0.431 (9)	0.6008 (9)	0.062 (10)*
C10	1.1589 (5)	−0.2639 (9)	0.56450 (8)	0.0473 (8)
C11	0.9690 (5)	−0.1103 (10)	0.56080 (8)	0.0514 (9)
H11	0.902 (5)	−0.092 (9)	0.5362 (9)	0.063 (10)*
C12	0.8682 (5)	−0.0049 (8)	0.59270 (8)	0.0417 (7)
H12	0.742 (5)	0.108 (9)	0.5893 (8)	0.052 (9)*
Cl13	1.28833 (18)	−0.3900 (3)	0.52474 (3)	0.0838 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0321 (12)	0.0390 (16)	0.0327 (12)	−0.0020 (11)	0.0021 (10)	−0.0013 (11)
N2	0.0264 (11)	0.0380 (15)	0.0307 (11)	0.0052 (11)	−0.0004 (9)	−0.0004 (10)
C3	0.0266 (12)	0.0283 (15)	0.0352 (13)	−0.0003 (12)	0.0016 (10)	0.0043 (12)
O4	0.0316 (10)	0.0512 (14)	0.0445 (11)	0.0149 (10)	−0.0025 (8)	0.0003 (10)
C5	0.0307 (14)	0.0371 (17)	0.0342 (14)	0.0034 (13)	−0.0026 (11)	0.0025 (13)
O6	0.0404 (10)	0.0479 (13)	0.0307 (9)	0.0165 (10)	−0.0024 (8)	−0.0001 (9)
C7	0.0363 (14)	0.0361 (17)	0.0301 (13)	−0.0001 (13)	0.0013 (11)	−0.0013 (12)
C8	0.0369 (15)	0.049 (2)	0.0379 (15)	0.0075 (14)	−0.0049 (12)	−0.0007 (14)
C9	0.0384 (16)	0.051 (2)	0.0537 (18)	0.0085 (16)	0.0029 (14)	−0.0046 (16)
C10	0.0562 (19)	0.046 (2)	0.0406 (16)	0.0091 (16)	0.0109 (14)	−0.0036 (14)
C11	0.063 (2)	0.061 (2)	0.0305 (14)	0.0130 (19)	−0.0030 (14)	0.0010 (16)
C12	0.0418 (16)	0.045 (2)	0.0375 (15)	0.0105 (14)	−0.0040 (12)	0.0009 (13)
Cl13	0.0958 (8)	0.1032 (9)	0.0543 (5)	0.0323 (7)	0.0293 (5)	−0.0067 (6)

Geometric parameters (Å, º)

N1—N2	1.420 (3)	C7—C12	1.381 (4)
N1—H1A	0.93 (4)	C7—C8	1.389 (4)
N1—H1B	0.89 (4)	C8—C9	1.367 (4)
N2—C3	1.319 (3)	C8—H8	0.94 (3)
N2—H2	0.86 (3)	C9—C10	1.376 (4)
C3—O4	1.237 (3)	C9—H9	0.92 (4)
C3—C5	1.499 (4)	C10—C11	1.372 (4)
C5—O6	1.419 (3)	C10—Cl13	1.734 (3)
C5—H5A	0.98 (3)	C11—C12	1.387 (4)
C5—H5B	0.94 (3)	C11—H11	0.96 (3)
O6—C7	1.372 (3)	C12—H12	0.93 (3)
N2—N1—H1A	107 (2)	O6—C7—C8	115.6 (2)
N2—N1—H1B	109 (2)	C12—C7—C8	119.8 (3)
H1A—N1—H1B	107 (3)	C9—C8—C7	120.1 (3)
C3—N2—N1	121.3 (2)	C9—C8—H8	121.4 (19)
C3—N2—H2	119.6 (19)	C7—C8—H8	118.4 (19)
N1—N2—H2	119.0 (19)	C8—C9—C10	120.0 (3)
O4—C3—N2	123.6 (2)	C8—C9—H9	123 (2)
O4—C3—C5	118.5 (2)	C10—C9—H9	117 (2)
N2—C3—C5	117.8 (2)	C11—C10—C9	120.5 (3)
O6—C5—C3	110.6 (2)	C11—C10—Cl13	120.3 (2)
O6—C5—H5A	111.3 (19)	C9—C10—Cl13	119.1 (3)
C3—C5—H5A	108.6 (17)	C10—C11—C12	120.0 (3)
O6—C5—H5B	108.7 (18)	C10—C11—H11	120 (2)
C3—C5—H5B	107.4 (19)	C12—C11—H11	120 (2)
H5A—C5—H5B	110 (3)	C7—C12—C11	119.5 (3)
C7—O6—C5	118.1 (2)	C7—C12—H12	122.2 (19)
O6—C7—C12	124.6 (3)	C11—C12—H12	118.1 (19)
N1—N2—C3—O4	−4.8 (4)	C7—C8—C9—C10	−1.6 (5)
N1—N2—C3—C5	173.5 (2)	C8—C9—C10—C11	0.1 (6)
O4—C3—C5—O6	−176.2 (3)	C8—C9—C10—Cl13	179.3 (3)
N2—C3—C5—O6	5.4 (4)	C9—C10—C11—C12	0.4 (6)
C3—C5—O6—C7	−164.9 (2)	Cl13—C10—C11—C12	−178.9 (3)
C5—O6—C7—C12	−6.7 (4)	O6—C7—C12—C11	178.9 (3)
C5—O6—C7—C8	174.5 (3)	C8—C7—C12—C11	−2.4 (5)
O6—C7—C8—C9	−178.4 (3)	C10—C11—C12—C7	0.8 (6)
C12—C7—C8—C9	2.8 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O4^i	0.93 (4)	2.51 (4)	3.160 (3)	127 (3)
N1—H1B···O4^ii	0.89 (4)	2.15 (4)	3.020 (3)	165 (3)
N2—H2···N1^iii	0.86 (3)	2.23 (3)	2.997 (3)	149 (3)
C8—H8···O4^iv	0.94 (3)	2.51 (3)	3.376 (3)	153 (2)

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