2-Acetyl­anilinium chloride

Abstract

The cation of the title salt, C₈H₁₀NO⁺·Cl⁻, is essentially planar [C—C—C—C torsion angle = 4.6 (2)°], the conformation being stabilized by an intra­molecular N—H⋯O hydrogen bond. In the crystal, centrosymmetric aggregates are formed via N—H⋯Cl hydrogen bonds. These dimeric aggregates are sustained in the crystal packing by a combination of C—H⋯Cl, C—H⋯O and C—O⋯π [O⋯ring centroid(benzene ring) = 3.1871 (13) and 3.3787 (13) Å] inter­actions.

Related literature

For background to structural studies of quinoline derivatives, see: Kaiser et al. (2009 ▶).

Experimental

Crystal data

• C₈H₁₀NO⁺·Cl⁻

• M _r = 171.62

• Monoclinic,

• a = 4.8979 (1) Å

• b = 15.8136 (4) Å

• c = 10.8203 (3) Å

• β = 102.569 (3)°

• V = 817.98 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.41 mm⁻¹

• T = 100 K

• 0.30 × 0.25 × 0.20 mm

Data collection

• Agilent Supernova Dual diffractometer with an Atlas detector

• Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.920, T _max = 1.000

• 3262 measured reflections

• 1436 independent reflections

• 1256 reflections with I > 2σ(I)

• R _int = 0.019

Refinement

• R[F ² > 2σ(F ²)] = 0.029

• wR(F ²) = 0.080

• S = 1.07

• 1436 reflections

• 113 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.20 e Å⁻³

• Δρ_min = −0.27 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1n⋯Cl1	0.95 (2)	2.23 (2)	3.1463 (15)	163 (2)
N1—H2n⋯Cl1i	0.92 (2)	2.24 (2)	3.1366 (15)	165 (2)
N1—H3n⋯O1	0.87 (2)	1.95 (2)	2.6778 (18)	140 (2)
C5—H5⋯Cl1ii	0.95	2.73	3.5332 (18)	142
C6—H6⋯O1iii	0.95	2.59	3.2496 (19)	127

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

Comment

The title salt, (I), was obtained as an unexpected product during the attempted synthesis of a quinoline derivative, investigated as a part of an on-going programme into the synthesis and structural chemistry of quinolines of interest owing to their putative anti-malarial activity (Kaiser et al., 2009).

Ionic (I), Fig. 1, comprises a 2-acetylanilinium cation and a chloride anion. The cation is essentially planar with the acetyl group only slightly twisted out of the plane of the benzene ring to which it is connected, the C1–C2–C3–C4 torsion angle = 4.6 (2) °. The observed conformation is stabilized by an intramolecular N–H···O hydrogen bond, Table 1.

In the crystal packing, centrosymmetrically related molecules are connected into a supramolecular dimer via N–H···Cl hydrogen bonds, Table 1 and Fig. 2. The dimeric aggregates are arranged into layers in the ac plane via a combination of C–H···O, Table 1, and C—O···π contacts [C2–O1···Cg(C3—C8)ⁱ = 3.1871 (13) Å with the angle at O1 = 96.44 (10) ° for i: 1 + x, y, z; and C2–O1···Cg(C3—C8)ⁱⁱ = 3.3787 (13) Å with the angle at O1 = 98.36 (9) ° for ii: x, 1/2 - y, -1/2 + z]. The presence of C–H···Cl interactions, Table 1, contributes to the stability of the structure along the b axis, Fig. 3.

Experimental

A mixture of 2-aminoacetophenone (0.01 M), acetophenone (0.01 M) and a catalytic amount of conc. HCl was heated on a water bath for 10 min. The resultant solid was filtered, dried and purified by column chromatography using a 1:5 mixture of ethyl acetate and hexane. Re-crystallization was by slow evaporation of an acetone solution of (I) which yielded colourless needles. M.pt. 421–423 K. Yield: 66%. The X-ray study showed that the original 2-aminoacetophenone had been protonated and crystallized as a chloride salt.

Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 to 0.98 Å) and were included in the refinement in the riding model approximation, with U_iso(H) set to 1.2 to 1.5U_equiv(C). The N-bound H-atoms were located in a difference Fourier map and refined freely.

Figures

Fig. 1.

The constituent ions of salt (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.

Fig. 2.

Supramolecular dimer in (I) mediated by N–H···Cl hydrogen bonding, shown as orange dashed lines.

Fig. 3.

Unit-cell contents shown in projection down the a axis in (I). The N–H···Cl hydrogen bonding, and C–H···Cl, C–H···O and C–O···π contacts are shown as orange, blue, pink, and purple dashed lines, respectively.

Crystal data

C8H10NO+·Cl−	F(000) = 360
Mr = 171.62	Dx = 1.394 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2016 reflections
a = 4.8979 (1) Å	θ = 2.3–29.1°
b = 15.8136 (4) Å	µ = 0.41 mm−1
c = 10.8203 (3) Å	T = 100 K
β = 102.569 (3)°	Pris,, colourless
V = 817.98 (3) Å3	0.30 × 0.25 × 0.20 mm
Z = 4

Data collection

Agilent Supernova Dual diffractometer with an Atlas detector	1436 independent reflections
Radiation source: SuperNova (Mo) X-ray Source	1256 reflections with I > 2σ(I)
Mirror	Rint = 0.019
Detector resolution: 10.4041 pixels mm-1	θmax = 25.0°, θmin = 2.3°
ω scans	h = −5→5
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	k = −18→17
Tmin = 0.920, Tmax = 1.000	l = −10→12
3262 measured reflections

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.080	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ2(Fo2) + (0.0393P)2 + 0.2093P] where P = (Fo2 + 2Fc2)/3
1436 reflections	(Δ/σ)max = 0.001
113 parameters	Δρmax = 0.20 e Å−3
0 restraints	Δρmin = −0.27 e Å−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
Cl1	0.10927 (9)	0.47141 (2)	0.83017 (4)	0.02647 (17)
O1	0.8706 (2)	0.23737 (7)	0.91735 (11)	0.0277 (3)
N1	0.6529 (3)	0.38178 (9)	0.98223 (14)	0.0210 (3)
H1N	0.508 (4)	0.4081 (12)	0.9220 (19)	0.036 (5)*
H2N	0.753 (4)	0.4233 (13)	1.0322 (19)	0.033 (5)*
H3N	0.759 (4)	0.3532 (12)	0.9418 (19)	0.034 (5)*
C1	0.7572 (5)	0.10071 (11)	0.97971 (19)	0.0377 (5)
H1A	0.8665	0.0826	0.9186	0.057*
H1B	0.5674	0.0776	0.9552	0.057*
H1C	0.8466	0.0800	1.0642	0.057*
C2	0.7435 (3)	0.19573 (10)	0.98154 (15)	0.0233 (4)
C3	0.5701 (3)	0.23753 (10)	1.06204 (15)	0.0197 (4)
C4	0.4392 (4)	0.18953 (10)	1.14121 (16)	0.0238 (4)
H4	0.4639	0.1299	1.1444	0.029*
C5	0.2751 (4)	0.22678 (11)	1.21474 (16)	0.0253 (4)
H5	0.1875	0.1928	1.2673	0.030*
C6	0.2381 (3)	0.31345 (10)	1.21206 (16)	0.0240 (4)
H6	0.1249	0.3391	1.2626	0.029*
C7	0.3663 (3)	0.36268 (10)	1.13559 (15)	0.0219 (4)
H7	0.3423	0.4223	1.1337	0.026*
C8	0.5289 (3)	0.32504 (10)	1.06211 (15)	0.0185 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0285 (3)	0.0215 (3)	0.0298 (3)	0.00177 (17)	0.00704 (19)	−0.00224 (17)
O1	0.0280 (7)	0.0299 (7)	0.0275 (7)	0.0043 (5)	0.0113 (6)	−0.0002 (5)
N1	0.0222 (8)	0.0193 (8)	0.0235 (8)	−0.0005 (7)	0.0091 (7)	0.0013 (7)
C1	0.0527 (13)	0.0241 (10)	0.0401 (12)	0.0081 (9)	0.0182 (10)	−0.0017 (9)
C2	0.0230 (9)	0.0236 (9)	0.0212 (9)	0.0040 (7)	0.0003 (7)	−0.0008 (7)
C3	0.0173 (8)	0.0210 (9)	0.0199 (8)	0.0010 (7)	0.0016 (7)	0.0006 (7)
C4	0.0251 (9)	0.0188 (9)	0.0262 (9)	0.0001 (7)	0.0027 (7)	0.0048 (7)
C5	0.0226 (9)	0.0300 (10)	0.0238 (9)	−0.0034 (8)	0.0060 (7)	0.0067 (8)
C6	0.0196 (9)	0.0304 (10)	0.0232 (9)	0.0015 (7)	0.0073 (7)	−0.0005 (8)
C7	0.0205 (9)	0.0191 (9)	0.0264 (9)	0.0015 (7)	0.0058 (7)	−0.0005 (7)
C8	0.0158 (8)	0.0205 (8)	0.0190 (8)	−0.0017 (6)	0.0031 (7)	0.0017 (7)

Geometric parameters (Å, °)

O1—C2	1.221 (2)	C3—C8	1.399 (2)
N1—C8	1.466 (2)	C3—C4	1.400 (2)
N1—H1N	0.95 (2)	C4—C5	1.380 (2)
N1—H2N	0.92 (2)	C4—H4	0.9500
N1—H3N	0.87 (2)	C5—C6	1.382 (2)
C1—C2	1.504 (2)	C5—H5	0.9500
C1—H1A	0.9800	C6—C7	1.383 (2)
C1—H1B	0.9800	C6—H6	0.9500
C1—H1C	0.9800	C7—C8	1.377 (2)
C2—C3	1.496 (2)	C7—H7	0.9500
C8—N1—H1N	109.3 (12)	C4—C3—C2	120.68 (15)
C8—N1—H2N	108.9 (12)	C5—C4—C3	121.54 (15)
H1N—N1—H2N	108.2 (16)	C5—C4—H4	119.2
C8—N1—H3N	110.2 (13)	C3—C4—H4	119.2
H1N—N1—H3N	108.7 (18)	C4—C5—C6	120.10 (16)
H2N—N1—H3N	111.5 (18)	C4—C5—H5	120.0
C2—C1—H1A	109.5	C6—C5—H5	120.0
C2—C1—H1B	109.5	C5—C6—C7	119.76 (16)
H1A—C1—H1B	109.5	C5—C6—H6	120.1
C2—C1—H1C	109.5	C7—C6—H6	120.1
H1A—C1—H1C	109.5	C8—C7—C6	119.82 (15)
H1B—C1—H1C	109.5	C8—C7—H7	120.1
O1—C2—C3	121.12 (15)	C6—C7—H7	120.1
O1—C2—C1	120.10 (16)	C7—C8—C3	121.98 (15)
C3—C2—C1	118.77 (15)	C7—C8—N1	116.21 (14)
C8—C3—C4	116.80 (15)	C3—C8—N1	121.80 (14)
C8—C3—C2	122.52 (14)
O1—C2—C3—C8	4.3 (2)	C5—C6—C7—C8	0.3 (2)
C1—C2—C3—C8	−175.12 (16)	C6—C7—C8—C3	−0.1 (2)
O1—C2—C3—C4	−176.05 (15)	C6—C7—C8—N1	178.95 (14)
C1—C2—C3—C4	4.6 (2)	C4—C3—C8—C7	−0.4 (2)
C8—C3—C4—C5	0.7 (2)	C2—C3—C8—C7	179.28 (15)
C2—C3—C4—C5	−179.04 (15)	C4—C3—C8—N1	−179.37 (15)
C3—C4—C5—C6	−0.4 (3)	C2—C3—C8—N1	0.3 (2)
C4—C5—C6—C7	−0.1 (3)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1n···Cl1	0.95 (2)	2.23 (2)	3.1463 (15)	162.9 (17)
N1—H2n···Cl1i	0.92 (2)	2.24 (2)	3.1366 (15)	165.0 (17)
N1—H3n···O1	0.87 (2)	1.946 (19)	2.6778 (18)	140.3 (18)
C5—H5···Cl1ii	0.95	2.73	3.5332 (18)	142
C6—H6···O1iii	0.95	2.59	3.2496 (19)	127

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