3-(1-Chlorovinyl)-2,4,6-trimethoxybenzaldehyde

Article abstract of DOI:10.1107/S0108270100014700

The title compound, C₁₂H₁₃ClO₄, was prepared from the Vilsmeier-Haack reaction on phloroacetophenone. The chlorovinyl and one of the methoxy substituents are twisted through about 75° with respect to the aromatic plane, whilst the other substituents are almost coplanar with the ring. Intermolecular hydrogen bonding involving C-H···O interactions generates one-dimensional chains in the direction of the a axis.

Full text of DOI:10.1107/S0108270100014700

organic compounds
(the largest torsional deviation being less than 7ꢁ). In contrast,
the torsion angles C8ÐO2ÐC2ÐC1 [73.4 (2)ꢁ] and C4ÐC3Ð
C9ÐCl1 [75.2 (2)ꢁ] (Table 1) illustrate the considerable
twisting of the C2 methoxy and chlorovinyl substituents with
respect to the aromatic ring.
Acta Crystallographica Section C
Crystal Structure
Communications
ISSN 0108-2701
3-(1-Chlorovinyl)-2,4,6-trimethoxy-
benzaldehyde
Atulya K. Panda,a M. R. Parthasarathya and William
Erringtonb*
aDepartment of Chemistry, University of Delhi, Delhi 110 007, India, and
bDepartment of Chemistry, University of Warwick, Coventry CV4 7AL, England
Correspondence e-mail: w.errington@warwick.ac.uk
Received 17 August 2000
Accepted 19 October 2000
The title compound, C12H13ClO4, was prepared from the
Vilsmeier±Haack reaction on phloroacetophenone. The
chlorovinyl and one of the methoxy substituents are twisted
through about 75ꢁ with respect to the aromatic plane, whilst
the other substituents are almost coplanar with the ring.
Intermolecular hydrogen bonding involving CÐHÁ Á ÁO inter-
actions generates one-dimensional chains in the direction of
the a axis.
The intermolecular forces responsible for the integrity of
the crystal are of interest. The shortest separation between the
Ê
centroids of aromatic rings is 4.12 A and suggests that any
intermolecular forces between these rings must be very weak.
A detailed analysis of the shortest intermolecular atomic
separations suggests that CÐHÁ Á ÁO hydrogen bonding is
likely to provide the major intermolecular forces. The
Ê
Ê
O1Á Á ÁC12(1 + x, y, z) separation of 2.998 (3) A is about 0.22 A
Comment
The Vilsmeier±Haack reaction, using disubstituted formamide
and phosphorous oxychloride, has been extensively employed
for the formylation of active aromatic rings yielding aryl-
aldehydes (Minkin & Dorofeenko, 1960), of acetophenones
yielding ꢀ-chloro-ꢀ-arylacroleins (Rosenblum et al., 1966) and
of ortho-hydroxyacetophenones yielding chromon-3-carbox-
aldehydes (Nohara et al., 1974). ꢀ-Chloro-ꢀ-arylacroleins have
been a source for arylacetylenes, which are useful for the
synthesis of 2-arylbenzofurans (Duf¯ey & Stevenson, 1977). In
continuation with our work on the synthesis of nor-neolignans
(Parthasarathy & Mohakhud, 1995), we have investigated the
formylation of phloroacetophenone trimethyl ether, (III).
Instead of the expected product, (I), we obtained a colourless
1
crystalline compound, (II), whose H NMR spectrum did not
show the expected coupling (J = 7 Hz) between the formyl
proton and the ꢁ-ole®nic proton (Parthasarathy & Mohakhud,
1995). Furthermore, the alkaline degradation of (II) to the
corresponding arylacetylene was very sluggish and required a
higher temperature and a longer reaction period than
reported earlier for compounds similar to (I). The resulting
product from alkaline degradation of (II) was a yellow crys-
talline material, containing a carbonyl group, as indicated by
IR and 13C NMR studies. The question of structural identity of
(II) was resolved using single-crystal X-ray diffraction.
Figure 1
View of a molecule of (II) showing the atomic numbering. Displacement
ellipsoids are drawn at the 50% probability level for non-H atoms.
less than the sum of the van der Waals radii of these two atoms
(Bondi, 1964); this suggests a weak C12ÐH contact to O1 and
is consistent with C12 adjoining the electron-withdrawing O4
atom which will impart a fractional positive charge on the C12
H atoms. Since the C12 methyl H atoms were re®ned as part of
a rigid group, the derived CÐHÁ Á ÁO angle may not provide a
reliable hydrogen-bonding parameter. The overall effect of
these CÐHÁ Á ÁO interactions [i.e. O1 to C12(1 + x, y, z) and
C12 to O1(x 1, y, z)] is to generate one-dimensional chains
in the direction of the a axis.
The molecular structure of (II) is illustrated in Fig. 1. The
bond lengths and angles are largely unremarkable. The
methoxy substituents at C4 and C6, together with the alde-
hyde group at C1, are almost coplanar with the aromatic ring
ꢀ
102 # 2001 International Union of Crystallography
Printed in Great Britain ± all rights reserved
Acta Cryst. (2001). C57, 102±103

organic compounds
Table 2
Short-contact geometry (A, ).
Experimental
ꢁ
Ê
POCl3 (0.3 ml) was added dropwise at 273 K to a shaken ¯ask
containing dry N,N-dimethylformamide (DMF) (0.3 ml). Phloro-
acetophenone trimethylether [(III), 0.4 g] in dry DMF (10 ml) was
added to the reaction mixture and the contents were heated on an oil
bath at 343±353 K for 6 h. The reaction mixture was then cooled to
273 K and a saturated solution of sodium acetate (25 ml) was added
slowly with shaking (as the reaction is exothermic). Instantaneous
precipitation occurred, the solid was ®ltered, washed with water and
dried to give a brown solid (0.33 g) which was then recrystallized from
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
C12ÐH12BÁ Á ÁO1i
0.98
2.48
2.998 (3)
113
Symmetry code: (i) x 1; y; z.
H atoms were added at calculated positions and re®ned using a
riding model. H atoms were given isotropic displacement parameters
equal to 1.2 (or 1.5 for methyl H atoms) times the equivalent isotropic
displacement parameters of their parent atoms and CÐH distances
Ê
were restrained to 0.95 A for those bonded to C5, C7 and C10, and
Ê
0.98 A for the remainder.
benzene/petrol to give colourless plates, melting at 388 K. IR (KBr)
1
ꢂ
max: 2944, 1676, 1641, 1589, 1140, 1103 cm 1. H NMR (300 MHz,
CDCl3): ꢃ (p.p.m.) 3.89 (3H, s), 3.94 (6H, s), 5.38 (1H, s), 5.76 (1H, s),
6.26 (1H, s), 10.32 (1H, s); 13C NMR (75.4 MHz, CDCl3): ꢃ (p.p.m.)
56.1 (q), 63.2 (q), 90.7 (d), 112.2 (s), 117.5 (s), 119.7 (t), 130.7 (s), 162.1
(s), 163.1 (s), 164.1 (s), 187.4 (d); ESMS (m/z, relative intensity):
257/259 (M+ + 1, 35/13), 243 (30.5), 227 (2), 222 (11), 221 (100), 206
(2), 193 (3), 178 (1), 165 (6), 161 (2.5), 122 (1.5), 105 (1).
Data collection: SMART (Siemens, 1994); cell re®nement: SAINT
(Siemens, 1994); data reduction: SAINT; program(s) used to solve
structure: SHELXTL/PC (Sheldrick, 1994); program(s) used to
re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:
SHELXTL/PC; software used to prepare material for publication:
SHELXTL/PC.
Crystal data
C12H13ClO4
Mr = 256.67
Triclinic, P1
a = 8.0516 (12) A
b = 8.1214 (12) A
Z = 2
Dx = 1.424 Mg m
Mo Kꢁ radiation
3
We wish to acknowledge the use of the EPSRC's Chemical
Database Service at Daresbury Laboratory (Fletcher et al.,
1996) for access to the Cambridge Structural Database (Allen
& Kennard, 1993). We also acknowledge Professor V. S.
Parmar for helpful discussions and CSIR (New Delhi) for
awarding a Senior Research Fellowship to one of the authors
(AKP).
Ê
Ê
Ê
Cell parameters from 2942
re¯ections
c = 9.9064 (15) A
ꢅ = 2.06±28.46ꢁ
ꢆ = 0.319 mm
T = 180 (2) K
1
ꢁ = 88.427 (4)ꢁ
ꢀ = 86.171 (4)ꢁ
ꢄ = 67.868 (3)ꢁ
Block, colourless
0.48 Â 0.28 Â 0.26 mm
3
Ê
V = 598.71 (15) A
Data collection
Siemens SMART CCD area-
detector diffractometer
! scans
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
Tmin = 0.862, Tmax = 0.922
3564 measured re¯ections
2478 independent re¯ections
2267 re¯ections with I > 2ꢇ(I)
Rint = 0.029
ꢅ
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: BM1428). Services for accessing these data are
described at the back of the journal.
max = 27.00ꢁ
h = 7 ! 10
k = 9 ! 10
l = 12 ! 11
Intensity decay: none
References
Allen, F. H. & Kennard, O. (1993). Chem. Des. Autom. News, 8, 1, 31±37.
Bondi, A. (1964). J. Phys. Chem. 68, 441±451.
Duf¯ey, R. P. & Stevenson, R. (1977). J. Chem. Soc. Perkin Trans. 1, pp. 802±
804.
Fletcher, D. A., McMeeking, R. F. & Parkin, D. (1996). J. Chem. Inf. Comput.
Sci. 36, 746±749.
Minkin, V. I. & Dorofeenko, G. N. (1960). Russ. Chem. Rev. 29, 599±618.
Nohara, A., Umetani, T. & Sanno, Y. (1974). Tetrahedron, 30, 3553±3561.
Parthasarathy, M. R. & Mohakhud, P. (1995). Indian J. Chem. Ser. B, 34, 713±
717.
Re®nement
Re®nement on F2
R[F2 > 2ꢇ(F2)] = 0.046
wR(F2) = 0.137
S = 1.102
2478 re¯ections
w = 1/[ꢇ2(Fo2) + (0.0703P)2
+ 0.3956P]
where P = (Fo2 + 2Fc2)/3
(Á/ꢇ)max < 0.001
3
Ê
Áꢈmax = 0.47 e A
3
Ê
0.71 e A
157 parameters
H-atom parameters constrained
Áꢈmin
=
Rosenblum, M., Brawn, N., Papenmeier, J. & Applebaum, M. (1966). J.
Organomet. Chem. 6, 173±180.
Sheldrick, G. M. (1994). SHELXTL/PC. Version 5.0. Siemens Analytical
X-ray Instruments Inc., Madison, Wisconsin, USA.
Table 1
Selected torsion angles (ꢁ).
È
Sheldrick, G. M. (1996). SADABS. University of Gottingen, Germany.
Sheldrick, G. M. (1997). SHELXL97. University of Gottingen, Germany.
Siemens (1994). SMART and SAINT. Version 4.021. Siemens Analytical X-ray
Instruments Inc., Madison, Wisconsin, USA.
C8ÐO2ÐC2ÐC1
C11ÐO3ÐC4ÐC5
C12ÐO4ÐC6ÐC5
73.4 (2)
0.6 (3)
6.6 (3)
C2ÐC1ÐC7ÐO1
C2ÐC3ÐC9ÐCl1
5.8 (3)
75.2 (2)
È
ꢀ
Acta Cryst. (2001). C57, 102±103
Atulya K. Panda et al. C12H13ClO4 103

supporting information
supporting information
Acta Cryst. (2001). C57, 102-103 [doi:10.1107/S0108270100014700]
3-(1-Chlorovinyl)-2,4,6-trimethoxybenzaldehyde
Atulya K. Panda, M. R. Parthasarathy and William Errington
Computing details
Data collection: SMART (Siemens, 1994); cell refinement: SAINT (Siemens, 1994); data reduction: SAINT; program(s)
used to solve structure: SHELXTL/PC (Sheldrick, 1994); program(s) used to refine structure: SHELXL97 (Sheldrick,
1997); molecular graphics: SHELXTL/PC; software used to prepare material for publication: SHELXTL/PC.
2,4,6-Trimethoxy-3-(1-chlorovinyl)benzaldehyde
Crystal data
C12H13ClO4
Z = 2
Mr = 256.67
Triclinic, P1
F(000) = 268
Dx = 1.424 Mg m−3
Mo Kα radiation, λ = 0.71073 Å
Cell parameters from 2942 reflections
θ = 2.1–28.5°
a = 8.0516 (12) Å
b = 8.1214 (12) Å
c = 9.9064 (15) Å
α = 88.427 (4)°
β = 86.171 (4)°
γ = 67.868 (3)°
V = 598.71 (15) Å3
µ = 0.32 mm−1
T = 180 K
Block, colourless
0.48 × 0.28 × 0.26 mm
Data collection
Siemens SMART CCD area-detector
diffractometer
Radiation source: normal-focus sealed tube
Graphite monochromator
Detector resolution: 8.192 pixels mm-1
ω scans
3564 measured reflections
2478 independent reflections
2267 reflections with I > 2σ(I)
Rint = 0.029
θmax = 27.0°, θmin = 2.1°
h = −7→10
k = −9→10
l = −12→11
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
T
min = 0.862, Tmax = 0.922
Refinement
Refinement on F2
Least-squares matrix: full
R[F2 > 2σ(F2)] = 0.046
wR(F2) = 0.137
Secondary atom site location: difference Fourier
map
Hydrogen site location: inferred from
neighbouring sites
S = 1.10
2478 reflections
157 parameters
0 restraints
Primary atom site location: structure-invariant
direct methods
H-atom parameters constrained
w = 1/[σ2(Fo2) + (0.0703P)2 + 0.3956P]
where P = (Fo2 + 2Fc2)/3
(Δ/σ)max < 0.001
Δρmax = 0.47 e Å−3
Δρmin = −0.71 e Å−3
Acta Cryst. (2001). C57, 102-103
sup-1

supporting information
Special details
Experimental. Data were collected over a hemisphere of reciprocal space, by a combination of three sets of exposures.
Each set had a different φ angle for the crystal and each exposure of 10 s covered 0.3° in ω. The crystal to detector
distance was 5.01 cm. Coverage of the unique set was over 94% complete to at least 27° in θ. Crystal decay was
monitored by repeating the initial frames at the end of the data collection and analyzing the duplicate reflections.
The temperature of the crystal was controlled using the Oxford Cryosystem Cryostream Cooler (Cosier & Glazer, 1986).
Cosier, J. & Glazer, A·M. (1986). J. Appl. Cryst. 19, 105–107.
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 (Å2)
x
y
z
Uiso*/Ueq
Cl1
0.76210 (8)
0.6511 (2)
0.77673 (17)
0.41735 (19)
0.20520 (18)
0.4888 (2)
0.6178 (2)
0.5946 (2)
0.4331 (2)
0.2988 (2)
0.1893
0.27513 (8)
0.8345 (2)
0.53509 (17)
0.19645 (18)
0.75418 (18)
0.6497 (2)
0.5200 (2)
0.3666 (2)
0.3459 (2)
0.4743 (2)
0.4601
0.51505 (5)
0.08684 (17)
0.25824 (13)
0.30810 (15)
0.06670 (15)
0.15621 (17)
0.23225 (17)
0.27865 (17)
0.25599 (18)
0.18613 (18)
0.1726
0.0492 (2)
0.0396 (4)
0.0269 (3)
0.0324 (3)
0.0321 (3)
0.0229 (4)
0.0220 (4)
0.0239 (4)
0.0246 (4)
0.0254 (4)
0.030*
O1
O2
O3
O4
C1
C2
C3
C4
C5
H5A
C6
0.3283 (2)
0.5202 (2)
0.4279
0.6238 (2)
0.7967 (2)
0.8694
0.13654 (17)
0.08371 (19)
0.0288
0.0236 (4)
0.0269 (4)
0.032*
C7
H7A
C8
0.7585 (3)
0.8779
0.6687 (3)
0.6605
0.3571 (2)
0.3800
0.0370 (5)
0.056*
H8A
H8B
H8C
C9
0.6921
0.6498
0.4387
0.056*
0.6930
0.7868
0.3197
0.056*
0.7383 (2)
0.8520 (3)
0.8417
0.2269 (2)
0.0699 (2)
0.0442
0.34914 (19)
0.2923 (2)
0.2010
0.0277 (4)
0.0324 (4)
0.039*
C10
H10A
H10B
C11
H11D
H11A
H11B
C12
H12A
H12B
H12C
0.9413
−0.0135
0.3442
0.039*
0.2550 (3)
0.2612
0.1670 (3)
0.0562
0.2897 (2)
0.3350
0.0393 (5)
0.059*
0.2415
0.1584
0.1929
0.059*
0.1518
0.2663
0.3288
0.059*
0.0484 (3)
−0.0256
0.7278 (3)
0.8298
0.0311 (2)
−0.0216
0.0350 (4)
0.053*
−0.0206
0.7158
0.1135
0.053*
0.0837
0.6194
−0.0231
0.053*
Acta Cryst. (2001). C57, 102-103
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supporting information
Atomic displacement parameters (Å2)
U11
U22
U33
U12
U13
U23
Cl1
O1
O2
O3
O4
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
0.0526 (4)
0.0309 (7)
0.0228 (6)
0.0332 (7)
0.0248 (7)
0.0226 (8)
0.0204 (8)
0.0246 (9)
0.0279 (9)
0.0223 (8)
0.0224 (8)
0.0249 (9)
0.0421 (11)
0.0269 (9)
0.0402 (11)
0.0386 (11)
0.0245 (9)
0.0513 (4)
0.0372 (8)
0.0288 (7)
0.0298 (7)
0.0329 (7)
0.0230 (8)
0.0241 (8)
0.0235 (8)
0.0242 (8)
0.0300 (9)
0.0257 (8)
0.0241 (8)
0.0442 (12)
0.0285 (9)
0.0176 (8)
0.0415 (11)
0.0436 (11)
0.0322 (3)
0.0559 (10)
0.0315 (7)
0.0407 (8)
0.0403 (8)
0.0237 (8)
0.0227 (8)
0.0234 (8)
0.0236 (8)
0.0267 (9)
0.0226 (8)
0.0314 (9)
0.0347 (10)
0.0305 (9)
0.0382 (10)
0.0495 (12)
0.0382 (11)
−0.0050 (3)
−0.0186 (6)
−0.0121 (5)
−0.0192 (6)
−0.0118 (6)
−0.0093 (7)
−0.0096 (7)
−0.0089 (7)
−0.0122 (7)
−0.0131 (7)
−0.0087 (7)
−0.0090 (7)
−0.0265 (10)
−0.0135 (8)
−0.0075 (7)
−0.0279 (10)
−0.0132 (8)
−0.0133 (2)
−0.0097 (6)
−0.0054 (5)
−0.0069 (6)
−0.0119 (5)
−0.0017 (6)
−0.0008 (6)
−0.0018 (6)
−0.0001 (7)
−0.0023 (6)
−0.0029 (6)
−0.0038 (7)
−0.0080 (9)
−0.0053 (7)
−0.0161 (8)
−0.0090 (9)
−0.0106 (8)
0.0038 (2)
0.0174 (7)
0.0015 (5)
0.0085 (6)
0.0094 (6)
0.0005 (6)
−0.0013 (6)
0.0003 (6)
0.0001 (6)
−0.0011 (7)
−0.0005 (6)
0.0043 (7)
−0.0029 (9)
0.0065 (7)
0.0032 (7)
0.0086 (9)
0.0054 (9)
Geometric parameters (Å, º)
Cl1—C9
O1—C7
O2—C2
O2—C8
O3—C4
O3—C11
O4—C6
O4—C12
C1—C2
1.739 (2)
C1—C6
1.412 (2)
1.206 (2)
1.372 (2)
1.441 (2)
1.352 (2)
1.438 (2)
1.358 (2)
1.426 (2)
1.412 (2)
C1—C7
C2—C3
C3—C4
C3—C9
C4—C5
C5—C6
C9—C10
1.470 (2)
1.390 (2)
1.406 (2)
1.479 (2)
1.395 (3)
1.392 (3)
1.369 (3)
C2—O2—C8
C4—O3—C11
C6—O4—C12
C2—C1—C6
C2—C1—C7
C6—C1—C7
O2—C2—C3
O2—C2—C1
C3—C2—C1
C2—C3—C4
C2—C3—C9
C4—C3—C9
114.04 (14)
118.57 (15)
118.37 (15)
117.30 (15)
124.03 (15)
118.26 (15)
116.62 (15)
121.48 (15)
121.83 (16)
118.75 (16)
120.49 (16)
120.75 (15)
O3—C4—C5
O3—C4—C3
C5—C4—C3
C6—C5—C4
O4—C6—C5
O4—C6—C1
C5—C6—C1
O1—C7—C1
C10—C9—C3
C10—C9—Cl1
C3—C9—Cl1
123.29 (16)
115.46 (16)
121.24 (16)
118.80 (16)
122.52 (16)
115.53 (15)
121.95 (16)
126.65 (17)
124.89 (17)
119.62 (15)
115.47 (14)
C8—O2—C2—C3
C8—O2—C2—C1
−109.77 (18)
73.4 (2)
O3—C4—C5—C6
C3—C4—C5—C6
179.93 (16)
1.0 (3)
Acta Cryst. (2001). C57, 102-103
sup-3

supporting information
C6—C1—C2—O2
C7—C1—C2—O2
C6—C1—C2—C3
C7—C1—C2—C3
O2—C2—C3—C4
C1—C2—C3—C4
O2—C2—C3—C9
C1—C2—C3—C9
C11—O3—C4—C5
C11—O3—C4—C3
C2—C3—C4—O3
C9—C3—C4—O3
C2—C3—C4—C5
C9—C3—C4—C5
−179.08 (15)
8.4 (3)
C12—O4—C6—C5
C12—O4—C6—C1
C4—C5—C6—O4
C4—C5—C6—C1
C2—C1—C6—O4
C7—C1—C6—O4
C2—C1—C6—C5
C7—C1—C6—C5
C2—C1—C7—O1
C6—C1—C7—O1
C2—C3—C9—C10
C4—C3—C9—C10
C2—C3—C9—Cl1
C4—C3—C9—Cl1
−6.6 (3)
173.58 (16)
179.52 (16)
−0.7 (3)
4.2 (2)
−168.25 (16)
179.21 (15)
−3.9 (3)
177.95 (15)
−9.1 (2)
−1.5 (2)
−1.9 (3)
175.37 (16)
0.6 (3)
171.06 (16)
−5.8 (3)
179.54 (17)
−177.75 (15)
2.9 (2)
−178.24 (19)
−103.1 (2)
76.1 (2)
1.2 (3)
75.24 (19)
−105.46 (17)
−178.08 (16)
Hydrogen-bond geometry (Å, º)
D—H···A
C12—H12B···O1i
D—H
0.98
H···A
D···A
D—H···A
2.48
2.998 (3)
113
Symmetry code: (i) x−1, y, z.
Acta Cryst. (2001). C57, 102-103
sup-4