3-(Acetyl­amino)benzoic acid

The title compound, C₉H₉NO₃, was crystallized from methanol. The monoclinic structure features one mol­ecule in the asymmetric unit. The topology of the O—H...O and N—H...O hydrogen-bond network can be characterized by the graph-set assignments C(9) and R₂²(14).

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.052
• wR factor = 0.037
• Data-to-parameter ratio = 7.8

checkCIF/PLATON results

No syntax errors found



Alert level A
REFLT03_ALERT_3_A  Reflection count < 85% complete (theta max?)
           From the CIF: _diffrn_reflns_theta_max           31.98
           From the CIF: _diffrn_reflns_theta_full          31.98
           From the CIF: _reflns_number_total               2325
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         2896
           Completeness (_total/calc)             80.28%
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.80

Alert level B
REFNR01_ALERT_3_B  Ratio of reflections to parameters is < 8 for a
            centrosymmetric structure
            sine(theta)/lambda                0.7452
            Proportion of unique data used    0.5105
            Ratio reflections to parameters   7.8092
PLAT088_ALERT_3_B Poor Data / Parameter Ratio ....................       7.81

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT353_ALERT_3_C Long    N-H Bond (0.87A)   N1     -   H1     ...       1.02 Ang.
PLAT355_ALERT_3_C Long    O-H Bond (0.82A)   O3     -   H7     ...       1.03 Ang.
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C3     -   C7     ...       1.55 Ang.

Alert level G
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
           From the CIF: _diffrn_reflns_theta_max           31.98
           From the CIF: _reflns_number_total               2325
           From the CIF: _diffrn_reflns_limit_ max hkl    4.   14.   26.
           From the CIF: _diffrn_reflns_limit_ min hkl   -5.  -15.  -27.
           TEST1: Expected hkl limits for theta max
           Calculated maximum hkl    5.   15.   29.
           Calculated minimum hkl   -5.  -15.  -29.
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K

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

   3 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
   6 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 crystal structures of 2-acetylaminobenzoic acid, (I) (Kovalevsky, 1999; Mascarenhas et al., 1980; Rajnikant & Deshmukh, 2004), and 4-acetylaminobenzoic acid, (III) (Kashino et al., 1986; Feeder & Jones, 1992), have been described in the literature. The crystal structure of the title compound (II) has not been solved to date. Therefore, in the present work, we have attempted to fill this gap (Fig. 1, Table 1).

The dihedral angle in (II) between the mean plane of the aromatic ring and the plane of atoms C7/O3/O1 is 6.5 (3)°. The corresponding angle between the ring and the acetyl group C2/C1/N1/C8 is 6.3 (3)°.

The unit-cell packing of (II) is shown in Figs. 2 and 3. The molecules form layers held together by N—H···O and O—H···O hydrogen bonds. The layers interact with each other by van der Waals forces. The topology of the hydrogen-bond network of (II) can be described by the graph-set assignments introduced by Etter (1990) as a C(9) chain along the c axis and an R₂²(14) intermolecular ring. The hydrogen-bond networks in (I) and (III) can be characterized as S(6) and C(8), and C(4) and R₂²(8), respectively.

Related literature

For the crystal structures of the ortho- and para-isomers of the title compound, see: Feeder & Jones (1992); Kashino et al. (1986); Kovalevsky (1999); Mascarenhas et al. (1980); Rajnikant & Deshmukh (2004).

For related literature, see: Etter (1990).

S2. Experimental

A commercial sample of 3-acetylaminobenzoic acid was used. Single crystals of (II) were grown from a water–methanol solution by vapour diffusion of water.

S3. Refinement

The crystals of (II) were of poor quality and weakly diffracting, which accounts for the low fraction of measured reflections. All H atoms, except for those attached to the C9 methyl group, were located in difference maps and their positions and U_iso values were refined freely. The C9 H atoms were positioned geometrically over two orientations of equal occupancy and refined as riding, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C9).

Computing details

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku, 2005); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Watkin et al., 1996); molecular graphics: CrystalStructure; software used to prepare material for publication: CrystalStructure.

Figures

	Fig. 1. A view of (II), showing displacement ellipsoids drawn at the 40% probability level (arbitrary spheres for the H atoms).
	Fig. 2. A projection of the molecular packing of (II) along the a axis.
	Fig. 3. A projection of the molecular packing of (II) along the b axis.
	Fig. 4. Compounds (I), (II) and (III).

3-(Acetylamino)benzoic acid

Crystal data

C9H9NO3	F(000) = 376.00
Mr = 179.17	Dx = 1.422 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2yn	Cell parameters from 1899 reflections
a = 3.9522 (15) Å	θ = 2.8–30.5°
b = 10.699 (4) Å	µ = 0.11 mm^−1
c = 19.831 (7) Å	T = 293 K
β = 93.393 (8)°	Prism, colourless
V = 837.1 (5) Å^3	0.60 × 0.10 × 0.05 mm
Z = 4

Data collection

Rigaku Saturn CCD area-detector diffractometer	1168 reflections with F^2 > 2σ(F^2)
Detector resolution: 7.31 pixels mm^-1	Rint = 0.031
ω scans	θmax = 32.0°
Absorption correction: multi-scan (Jacobson, 1998)	h = −5→4
Tmin = 0.937, Tmax = 0.995	k = −15→14
9339 measured reflections	l = −27→26
2325 independent reflections

Refinement

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/σ^2(Fo)
R[F^2 > 2σ(F^2)] = 0.052	(Δ/σ)max = 0.012
wR(F^2) = 0.037	Δρmax = 0.22 e Å^−3
S = 1.50	Δρmin = −0.17 e Å^−3
1187 reflections	Extinction correction: Larson (1970), equation 22
152 parameters	Extinction coefficient: 50 (6)
H atoms treated by a mixture of independent and constrained refinement

Special details

Refinement. Refinement using reflections with F² > 2.0 σ(F²). The weighted R-factor(wR), goodness of fit (S) and R-factor (gt) are based on F, with F set to zero for negative F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
O1	0.4578 (5)	0.19844 (17)	0.24639 (8)	0.0669 (6)
O2	0.9126 (4)	0.11335 (16)	−0.10208 (8)	0.0619 (6)
O3	0.7144 (5)	0.30147 (17)	−0.12845 (10)	0.0696 (7)
N1	0.6495 (5)	0.09474 (19)	0.15195 (10)	0.0443 (6)
C1	0.5574 (5)	0.1793 (2)	0.10074 (11)	0.0388 (7)
C2	0.6738 (6)	0.1521 (2)	0.03496 (12)	0.0403 (7)
C3	0.6057 (5)	0.2333 (2)	−0.01719 (11)	0.0393 (7)
C4	0.4122 (6)	0.3398 (2)	−0.00383 (12)	0.0448 (8)
C5	0.2922 (6)	0.3649 (2)	0.06125 (13)	0.0477 (8)
C6	0.3639 (6)	0.2857 (2)	0.11430 (12)	0.0436 (7)
C7	0.7576 (6)	0.2074 (2)	−0.08637 (12)	0.0462 (8)
C8	0.5988 (6)	0.1067 (2)	0.21953 (12)	0.0477 (8)
C9	0.7234 (6)	−0.0009 (2)	0.25989 (12)	0.0614 (9)
H1	0.780 (5)	0.021 (2)	0.1341 (11)	0.077 (9)*
H2	0.822 (4)	0.0766 (18)	0.0236 (10)	0.044 (6)*
H4	0.377 (5)	0.396 (2)	−0.0423 (11)	0.056 (7)*
H5	0.147 (5)	0.4411 (19)	0.0738 (10)	0.055 (7)*
H6	0.272 (4)	0.3037 (17)	0.1606 (10)	0.042 (6)*
H7	0.821 (7)	0.286 (2)	−0.1736 (17)	0.120 (11)*
H8	0.7098	−0.0743	0.2329	0.073*	0.50
H9	0.5888	−0.0111	0.2976	0.073*	0.50
H10	0.9525	0.0133	0.2752	0.073*	0.50
H11	0.9227	−0.0622	0.2293	0.073*	0.50
H12	0.8177	0.0348	0.3013	0.073*	0.50
H13	0.5133	−0.0634	0.2731	0.073*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.1056 (16)	0.0619 (13)	0.0334 (10)	0.0159 (11)	0.0067 (10)	−0.0059 (9)
O2	0.0922 (14)	0.0543 (12)	0.0395 (11)	0.0146 (11)	0.0056 (9)	−0.0051 (9)
O3	0.1094 (17)	0.0633 (14)	0.0367 (11)	0.0188 (11)	0.0093 (11)	0.0114 (10)
N1	0.0594 (13)	0.0427 (13)	0.0305 (11)	0.0021 (11)	0.0009 (9)	−0.0005 (10)
C1	0.0475 (15)	0.0381 (14)	0.0305 (13)	−0.0041 (12)	0.0005 (11)	0.0006 (11)
C2	0.0507 (15)	0.0382 (14)	0.0320 (14)	0.0001 (13)	0.0012 (11)	−0.0035 (12)
C3	0.0471 (14)	0.0395 (14)	0.0308 (14)	−0.0066 (12)	−0.0006 (11)	−0.0008 (12)
C4	0.0528 (17)	0.0443 (16)	0.0367 (15)	−0.0042 (13)	−0.0024 (13)	0.0028 (13)
C5	0.0507 (16)	0.0421 (16)	0.0502 (17)	0.0055 (13)	0.0027 (13)	−0.0021 (14)
C6	0.0527 (16)	0.0437 (15)	0.0347 (14)	0.0001 (13)	0.0052 (12)	−0.0052 (13)
C7	0.0576 (17)	0.0468 (16)	0.0334 (15)	−0.0053 (14)	−0.0042 (12)	0.0007 (13)
C8	0.0571 (17)	0.0521 (17)	0.0339 (15)	−0.0091 (14)	0.0027 (12)	0.0007 (14)
C9	0.079 (2)	0.0635 (19)	0.0407 (17)	0.0043 (16)	−0.0060 (15)	0.0121 (15)

Geometric parameters (Å, º)

O1—C8	1.262 (3)	C5—C6	1.368 (3)
O2—C7	1.228 (3)	C8—C9	1.471 (3)
O3—C7	1.312 (3)	O3—H7	1.02 (3)
N1—C1	1.392 (2)	N1—H1	1.02 (2)
N1—C8	1.373 (3)	C2—H2	1.031 (19)
C1—C2	1.438 (3)	C4—H4	0.97 (2)
C1—C6	1.406 (3)	C5—H5	1.04 (2)
C2—C3	1.365 (3)	C6—H6	1.03 (2)
C3—C4	1.406 (3)	C9—H8	0.950
C3—C7	1.555 (3)	C9—H9	0.950
C4—C5	1.427 (3)	C9—H10	0.950
C1—N1—C8	127.2 (2)	C1—C2—H2	125.0 (11)
N1—C1—C2	116.5 (2)	C3—C2—H2	115.0 (11)
N1—C1—C6	120.5 (2)	C3—C4—H4	113.8 (13)
C2—C1—C6	122.9 (2)	C5—C4—H4	123.7 (13)
C1—C2—C3	120.0 (2)	C4—C5—H5	125.8 (12)
C2—C3—C4	117.2 (2)	C6—C5—H5	113.3 (12)
C2—C3—C7	119.1 (2)	C1—C6—H6	123.2 (10)
C4—C3—C7	123.6 (2)	C5—C6—H6	120.3 (10)
C3—C4—C5	122.5 (2)	C8—C9—H8	109.6
C4—C5—C6	120.9 (2)	C8—C9—H9	109.5
C1—C6—C5	116.4 (2)	C8—C9—H10	109.4
O2—C7—O3	121.0 (2)	C8—C9—H11	110.9
O2—C7—C3	126.5 (2)	C8—C9—H12	104.7
O3—C7—C3	112.5 (2)	C8—C9—H13	111.7
O1—C8—N1	125.3 (2)	H8—C9—H9	109.5
O1—C8—C9	121.4 (2)	H8—C9—H10	109.5
N1—C8—C9	113.2 (2)	H9—C9—H10	109.5
C7—O3—H7	112.8 (16)	H11—C9—H12	114.3
C1—N1—H1	111.4 (13)	H11—C9—H13	108.0
C8—N1—H1	121.3 (13)	H12—C9—H13	107.2
C1—N1—C8—O1	−0.1 (2)	C1—C2—C3—C7	175.3 (2)
C1—N1—C8—C9	179.2 (2)	C2—C3—C4—C5	0.7 (3)
C8—N1—C1—C2	172.9 (2)	C2—C3—C7—O2	7.3 (3)
C8—N1—C1—C6	−6.3 (3)	C2—C3—C7—O3	−170.5 (2)
N1—C1—C2—C3	−177.3 (2)	C4—C3—C7—O2	−175.8 (2)
N1—C1—C6—C5	178.5 (2)	C4—C3—C7—O3	6.4 (3)
C2—C1—C6—C5	−0.7 (3)	C7—C3—C4—C5	−176.3 (2)
C6—C1—C2—C3	1.9 (3)	C3—C4—C5—C6	0.5 (3)
C1—C2—C3—C4	−1.8 (3)	C4—C5—C6—C1	−0.5 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H7···O1^i	1.02 (3)	1.71 (3)	2.714 (2)	164 (2)
N1—H1···O2^ii	1.02 (2)	2.01 (2)	3.022 (2)	173.3 (18)

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