3-Chloro­propio­phenone

Sonneck, M.; Spannenberg, A.; Wohlrab, S.; Peppel, T.

doi:10.1107/S2414314625003499

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 10| Part 4| April 2025| x250349

https://doi.org/10.1107/S2414314625003499

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3-Chloropropiophenone

Marcel Sonneck,^a Anke Spannenberg,^a Sebastian Wohlrab ^a and Tim Peppel ^a ^*

^aLeibniz-Institut für Katalyse e. V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
^*Correspondence e-mail: tim.peppel@catalysis.de

Edited by M. Bolte, Goethe-Universität Frankfurt, Germany (Received 14 April 2025; accepted 17 April 2025; online 29 April 2025)

The title compound, 3-chloropropiophenone (or 3-chloro-1-phenylpropan-1-one), C₉H₉ClO, consists of an almost planar molecule that is charaterized by very small torsion angles within the alkyl side chain (torsion angles < 6.3°). No hydrogen bonds are observed in the crystal packing. The compound exhibits a melting point of 54°C.

Keywords: crystal structure; 3-chloropropiophenone; β-chloro ketone.

CCDC reference: 1501322

Structure description

β-Chloro ketones are useful building blocks for many chemical transformation reactions. They are accessible via different reaction schemes such as Friedel-Crafts acylation (Sartori & Maggi, 2006 ), Wacker-type oxidation (Liu et al., 2017 ), or light-mediated ring opening of aryl cyclopropanes (Petzold et al., 2019 ). The title compound was obtained in almost quantitative yield in high purity. It can be designated as a suitable building block in the ongoing efforts to synthesize feasible new ligands for Cu-based complexes (Sonneck et al., 2015 , 2016 ).

The molecular structure of 3-chloropropiophenone is almost planar with torsion angles of less than 6.3 degrees [maximum torsion angle: C1—C2—C3—O1 = −6.21 (19)°] in the side chain (Fig. 1). The main deviation out of the plane defined by the non-hydrogen atoms of the molecule is observed for O1 with −0.1091 (10) Å and for Cl1 with 0.1065 (8) Å. In addition, the layered packing prevents the formation of extended halogen or hydrogen-bonding networks. The molecules form stacks along the c axis. In a stack, neighbouring molecules are related by the c glide plane. All bond lengths and angles are within the expected range and the C=O bond is 1.2158 (18) Å.

Figure 1
Molecular structure of the title compound with atom labelling and displacement ellipsoids drawn at 50% probability level.

Synthesis and crystallization

3-Chloropropiophenone was obtained as colourless crystals in quantitative yield from the Friedel–Crafts acylation of benzene and 3-chloropropionyl chloride in dichloromethane. AlCl₃ (38.2 g, 286.5 mmol, 1.25 eq.) was suspended in 50 ml of dry dichloromethane at 0°C. A solution of 3-chloropropionyl chloride (29.1 g, 229.2 mmol, 1.0 eq.) in 90 ml dichloromethane was added dropwise at 0°C to the AlCl₃ suspension. Afterwards, a solution of benzene (17.9 g, 229.2 mmol, 1.0 eq.) in 25 mL dichloromethane was added dropwise at 0°C to the suspension and further stirred for 2 h at 0°C and 12 h at ambient conditions. The final solution was poured onto ice and concentrated hydrochloric acid (70 g:7 g) and after separation of the organic phase, the aqueous phase was extracted twice with 100 ml portions of dichloromethane. The combined organic phases were extracted twice with 150 ml portions of water and finally dried over Na₂SO₄. The solvent was removed completely under diminished pressure and the off-white crystalline solid residue was recrystallized from pentane to yield the final product (37.5 g, 97%). Colourless single crystals of 3-chloropropiophenone were obtained from a pentane solution by slow evaporation of the solvent at 4°C over the period of one week. Analytic data for C₉H₉ClO: m.p. 54°C, elemental analysis % (calculated): C 64.14 (64.11), H 5.25 (5.38); Cl 21.01 (21.02). ¹H NMR (400 MHz, CDCl₃): δ (p.p.m.) = 7.98–7.93 (m, 2H, ArH); 7.61–7.56 (m, 1H, ArH); 7.51–7.45 (m, 2H, ArH); 3.92 (t, ³J = 6.8 Hz, 2H); 3.45 (t, ³J = 6.7 Hz, 2H); ¹³C NMR (100 MHz, CDCl₃): δ (p.p.m.) = 196.78 (CO); 136.45 (C); 133.65, 128.84, 128.84, 128.14, 128.14 (CH); 41.36, 38.79 (CH₂).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

Table 1
Experimental details

Crystal data
Chemical formula	C₉H₉ClO
M_r	168.61
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	150
a, b, c (Å)	5.4485 (13), 20.347 (5), 7.4860 (17)
β (°)	102.123 (4)
V (Å³)	811.4 (3)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.40
Crystal size (mm)	0.51 × 0.43 × 0.07

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 )
T_min, T_max	0.79, 0.97
No. of measured, independent and observed [I > 2σ(I)] reflections	9113, 1951, 1595
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.661

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.095, 1.08
No. of reflections	1951
No. of parameters	100
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.36, −0.24
Computer programs: APEX2 (Bruker, 2014 ), SAINT (Bruker, 2013 ), SHELXS97 (Sheldrick, 2008 ), SHELXL2014/7 (Sheldrick, 2015 ), XP in SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1501322

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314625003499/bt4169sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314625003499/bt4169Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314625003499/bt4169Isup3.cml

checkCIF report

Computing details top

3-Chloro-1-phenylpropan-1-one top

Crystal data top

C₉H₉ClO	F(000) = 352
M_r = 168.61	D_x = 1.380 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 5.4485 (13) Å	Cell parameters from 2965 reflections
b = 20.347 (5) Å	θ = 3.0–28.7°
c = 7.4860 (17) Å	µ = 0.40 mm⁻¹
β = 102.123 (4)°	T = 150 K
V = 811.4 (3) Å³	Plate, colourless
Z = 4	0.51 × 0.43 × 0.07 mm

Data collection top

Bruker APEXII CCD diffractometer	1951 independent reflections
Radiation source: fine-focus sealed tube	1595 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm^-1	R_int = 0.032
φ and ω scans	θ_max = 28.0°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −7→7
T_min = 0.79, T_max = 0.97	k = −26→25
9113 measured reflections	l = −9→9

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.038	H-atom parameters constrained
wR(F²) = 0.095	w = 1/[σ²(F_o²) + (0.0414P)² + 0.259P] where P = (F_o² + 2F_c²)/3
S = 1.08	(Δ/σ)_max < 0.001
1951 reflections	Δρ_max = 0.36 e Å⁻³
100 parameters	Δρ_min = −0.24 e Å⁻³
0 restraints

Special details top

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. Hydrogen atoms were located in a difference map and refined as riding on their parent atoms with U(H)=1.2U_eq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.4181 (3)	0.91110 (7)	0.3732 (2)	0.0292 (3)
H1A	0.5586	0.9205	0.3120	0.035*
H1B	0.4812	0.9154	0.5067	0.035*
C2	0.3239 (3)	0.84182 (7)	0.3283 (2)	0.0243 (3)
H2A	0.1794	0.8331	0.3859	0.029*
H2B	0.2658	0.8373	0.1944	0.029*
C3	0.5285 (3)	0.79232 (7)	0.39585 (19)	0.0252 (3)
C4	0.4665 (3)	0.72090 (7)	0.38053 (19)	0.0229 (3)
C5	0.6530 (3)	0.67574 (8)	0.4561 (2)	0.0283 (3)
H5	0.8139	0.6911	0.5163	0.034*
C6	0.6055 (3)	0.60927 (8)	0.4438 (2)	0.0313 (4)
H6	0.7334	0.5789	0.4953	0.038*
C7	0.3713 (3)	0.58649 (8)	0.3564 (2)	0.0309 (3)
H7	0.3389	0.5406	0.3484	0.037*
C8	0.1843 (3)	0.63050 (8)	0.2808 (2)	0.0280 (3)
H8	0.0241	0.6148	0.2205	0.034*
C9	0.2314 (3)	0.69757 (7)	0.29323 (19)	0.0245 (3)
H9	0.1026	0.7277	0.2419	0.029*
Cl1	0.17021 (9)	0.96882 (2)	0.29882 (7)	0.04702 (17)
O1	0.7414 (2)	0.81030 (6)	0.46074 (17)	0.0399 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0317 (8)	0.0274 (7)	0.0294 (8)	−0.0056 (6)	0.0081 (6)	−0.0028 (6)
C2	0.0243 (7)	0.0254 (7)	0.0237 (7)	−0.0038 (5)	0.0064 (6)	−0.0007 (5)
C3	0.0227 (7)	0.0327 (8)	0.0202 (7)	−0.0042 (6)	0.0050 (6)	0.0002 (6)
C4	0.0221 (7)	0.0290 (7)	0.0190 (6)	−0.0001 (5)	0.0074 (6)	0.0011 (5)
C5	0.0214 (7)	0.0381 (8)	0.0254 (8)	0.0028 (6)	0.0051 (6)	0.0014 (6)
C6	0.0298 (8)	0.0356 (8)	0.0303 (8)	0.0108 (6)	0.0103 (7)	0.0052 (6)
C7	0.0375 (9)	0.0266 (7)	0.0317 (8)	0.0034 (6)	0.0144 (7)	0.0011 (6)
C8	0.0256 (8)	0.0295 (7)	0.0294 (8)	−0.0017 (6)	0.0065 (6)	−0.0001 (6)
C9	0.0216 (7)	0.0277 (7)	0.0243 (7)	0.0015 (5)	0.0052 (6)	0.0027 (5)
Cl1	0.0454 (3)	0.0260 (2)	0.0684 (3)	0.00011 (18)	0.0092 (2)	−0.00376 (19)
O1	0.0255 (6)	0.0408 (7)	0.0487 (8)	−0.0080 (5)	−0.0034 (5)	0.0026 (5)

Geometric parameters (Å, º) top

C1—C2	1.514 (2)	C4—C5	1.399 (2)
C1—Cl1	1.7882 (17)	C5—C6	1.377 (2)
C1—H1A	0.9900	C5—H5	0.9500
C1—H1B	0.9900	C6—C7	1.386 (2)
C2—C3	1.509 (2)	C6—H6	0.9500
C2—H2A	0.9900	C7—C8	1.385 (2)
C2—H2B	0.9900	C7—H7	0.9500
C3—O1	1.2158 (18)	C8—C9	1.388 (2)
C3—C4	1.491 (2)	C8—H8	0.9500
C4—C9	1.393 (2)	C9—H9	0.9500

C2—C1—Cl1	110.12 (11)	C5—C4—C3	118.39 (13)
C2—C1—H1A	109.6	C6—C5—C4	120.52 (14)
Cl1—C1—H1A	109.6	C6—C5—H5	119.7
C2—C1—H1B	109.6	C4—C5—H5	119.7
Cl1—C1—H1B	109.6	C5—C6—C7	120.13 (14)
H1A—C1—H1B	108.2	C5—C6—H6	119.9
C3—C2—C1	110.81 (12)	C7—C6—H6	119.9
C3—C2—H2A	109.5	C8—C7—C6	120.13 (15)
C1—C2—H2A	109.5	C8—C7—H7	119.9
C3—C2—H2B	109.5	C6—C7—H7	119.9
C1—C2—H2B	109.5	C7—C8—C9	119.92 (15)
H2A—C2—H2B	108.1	C7—C8—H8	120.0
O1—C3—C4	120.39 (14)	C9—C8—H8	120.0
O1—C3—C2	120.58 (14)	C8—C9—C4	120.33 (14)
C4—C3—C2	119.03 (12)	C8—C9—H9	119.8
C9—C4—C5	118.96 (14)	C4—C9—H9	119.8
C9—C4—C3	122.65 (13)

Cl1—C1—C2—C3	−178.09 (10)	C3—C4—C5—C6	−179.35 (13)
C1—C2—C3—O1	−6.21 (19)	C4—C5—C6—C7	−0.1 (2)
C1—C2—C3—C4	174.28 (12)	C5—C6—C7—C8	0.1 (2)
O1—C3—C4—C9	−174.35 (14)	C6—C7—C8—C9	−0.3 (2)
C2—C3—C4—C9	5.2 (2)	C7—C8—C9—C4	0.4 (2)
O1—C3—C4—C5	5.2 (2)	C5—C4—C9—C8	−0.4 (2)
C2—C3—C4—C5	−175.26 (12)	C3—C4—C9—C8	179.21 (13)
C9—C4—C5—C6	0.2 (2)

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