Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100014700/bm1428sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270100014700/bm1428IIsup2.hkl |
CCDC reference: 158271
POCl3 (0.3 ml) was added dropwise at 273 K to a shaken flask containing dry N·N-dimethylformamide (DMF) (0.3 ml). Phloroacetophenone trimethylether (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 filtered, washed with water and dried to give a brown solid (0.33 g) which was then recrystallized from benzene/petrol to give colourless plates, melting at 388 K. IR (KBr) νmax: 2944, 1676, 1641, 1589, 1140, 1103 cm-1. 1H NMR (300 MHz, CDCl3): δ (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): δ (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, 35.0/13.0), 243 (30.5), 227 (2.0), 222 (11.0), 221 (100.0), 206 (2.0), 193 (3.0), 178 (1.00, 165 (6.0), 161 (2.5), 122 (1.5), 105 (1.0).
Hydrogen atoms were added at calculated positions and refined 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 C—H distances were restrained to 0.95 Å for those bonded to C5, C7 and C10 and 0.98 Å for others.
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.
Fig. 1. View of a molecule of (II) showing the atomic numbering. Displacement ellipsoids are drawn at the 50% probability level for non-H atoms. |
C12H13ClO4 | Z = 2 |
Mr = 256.67 | F(000) = 268 |
Triclinic, P1 | Dx = 1.424 Mg m−3 |
a = 8.0516 (12) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.1214 (12) Å | Cell parameters from 2942 reflections |
c = 9.9064 (15) Å | θ = 2.1–28.5° |
α = 88.427 (4)° | µ = 0.32 mm−1 |
β = 86.171 (4)° | T = 180 K |
γ = 67.868 (3)° | Block, colourless |
V = 598.71 (15) Å3 | 0.48 × 0.28 × 0.26 mm |
Siemens SMART CCD area-detector diffractometer | 2478 independent reflections |
Radiation source: normal-focus sealed tube | 2267 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.029 |
Detector resolution: 8.192 pixels mm-1 | θmax = 27.0°, θmin = 2.1° |
ω scans | h = −7→10 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | k = −9→10 |
Tmin = 0.862, Tmax = 0.922 | l = −12→11 |
3564 measured reflections |
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)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0703P)2 + 0.3956P] where P = (Fo2 + 2Fc2)/3 |
2478 reflections | (Δ/σ)max < 0.001 |
157 parameters | Δρmax = 0.47 e Å−3 |
0 restraints | Δρmin = −0.71 e Å−3 |
C12H13ClO4 | γ = 67.868 (3)° |
Mr = 256.67 | V = 598.71 (15) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.0516 (12) Å | Mo Kα radiation |
b = 8.1214 (12) Å | µ = 0.32 mm−1 |
c = 9.9064 (15) Å | T = 180 K |
α = 88.427 (4)° | 0.48 × 0.28 × 0.26 mm |
β = 86.171 (4)° |
Siemens SMART CCD area-detector diffractometer | 2478 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2267 reflections with I > 2σ(I) |
Tmin = 0.862, Tmax = 0.922 | Rint = 0.029 |
3564 measured reflections |
R[F2 > 2σ(F2)] = 0.046 | 0 restraints |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.10 | Δρmax = 0.47 e Å−3 |
2478 reflections | Δρmin = −0.71 e Å−3 |
157 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cl1 | 0.76210 (8) | 0.27513 (8) | 0.51505 (5) | 0.0492 (2) | |
O1 | 0.6511 (2) | 0.8345 (2) | 0.08684 (17) | 0.0396 (4) | |
O2 | 0.77673 (17) | 0.53509 (17) | 0.25824 (13) | 0.0269 (3) | |
O3 | 0.41735 (19) | 0.19645 (18) | 0.30810 (15) | 0.0324 (3) | |
O4 | 0.20520 (18) | 0.75418 (18) | 0.06670 (15) | 0.0321 (3) | |
C1 | 0.4888 (2) | 0.6497 (2) | 0.15621 (17) | 0.0229 (4) | |
C2 | 0.6178 (2) | 0.5200 (2) | 0.23225 (17) | 0.0220 (4) | |
C3 | 0.5946 (2) | 0.3666 (2) | 0.27865 (17) | 0.0239 (4) | |
C4 | 0.4331 (2) | 0.3459 (2) | 0.25599 (18) | 0.0246 (4) | |
C5 | 0.2988 (2) | 0.4743 (2) | 0.18613 (18) | 0.0254 (4) | |
H5A | 0.1893 | 0.4601 | 0.1726 | 0.030* | |
C6 | 0.3283 (2) | 0.6238 (2) | 0.13654 (17) | 0.0236 (4) | |
C7 | 0.5202 (2) | 0.7967 (2) | 0.08371 (19) | 0.0269 (4) | |
H7A | 0.4279 | 0.8694 | 0.0288 | 0.032* | |
C8 | 0.7585 (3) | 0.6687 (3) | 0.3571 (2) | 0.0370 (5) | |
H8A | 0.8779 | 0.6605 | 0.3800 | 0.056* | |
H8B | 0.6921 | 0.6498 | 0.4387 | 0.056* | |
H8C | 0.6930 | 0.7868 | 0.3197 | 0.056* | |
C9 | 0.7383 (2) | 0.2269 (2) | 0.34914 (19) | 0.0277 (4) | |
C10 | 0.8520 (3) | 0.0699 (2) | 0.2923 (2) | 0.0324 (4) | |
H10A | 0.8417 | 0.0442 | 0.2010 | 0.039* | |
H10B | 0.9413 | −0.0135 | 0.3442 | 0.039* | |
C11 | 0.2550 (3) | 0.1670 (3) | 0.2897 (2) | 0.0393 (5) | |
H11D | 0.2612 | 0.0562 | 0.3350 | 0.059* | |
H11A | 0.2415 | 0.1584 | 0.1929 | 0.059* | |
H11B | 0.1518 | 0.2663 | 0.3288 | 0.059* | |
C12 | 0.0484 (3) | 0.7278 (3) | 0.0311 (2) | 0.0350 (4) | |
H12A | −0.0256 | 0.8298 | −0.0216 | 0.053* | |
H12B | −0.0206 | 0.7158 | 0.1135 | 0.053* | |
H12C | 0.0837 | 0.6194 | −0.0231 | 0.053* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0526 (4) | 0.0513 (4) | 0.0322 (3) | −0.0050 (3) | −0.0133 (2) | 0.0038 (2) |
O1 | 0.0309 (7) | 0.0372 (8) | 0.0559 (10) | −0.0186 (6) | −0.0097 (6) | 0.0174 (7) |
O2 | 0.0228 (6) | 0.0288 (7) | 0.0315 (7) | −0.0121 (5) | −0.0054 (5) | 0.0015 (5) |
O3 | 0.0332 (7) | 0.0298 (7) | 0.0407 (8) | −0.0192 (6) | −0.0069 (6) | 0.0085 (6) |
O4 | 0.0248 (7) | 0.0329 (7) | 0.0403 (8) | −0.0118 (6) | −0.0119 (5) | 0.0094 (6) |
C1 | 0.0226 (8) | 0.0230 (8) | 0.0237 (8) | −0.0093 (7) | −0.0017 (6) | 0.0005 (6) |
C2 | 0.0204 (8) | 0.0241 (8) | 0.0227 (8) | −0.0096 (7) | −0.0008 (6) | −0.0013 (6) |
C3 | 0.0246 (9) | 0.0235 (8) | 0.0234 (8) | −0.0089 (7) | −0.0018 (6) | 0.0003 (6) |
C4 | 0.0279 (9) | 0.0242 (8) | 0.0236 (8) | −0.0122 (7) | −0.0001 (7) | 0.0001 (6) |
C5 | 0.0223 (8) | 0.0300 (9) | 0.0267 (9) | −0.0131 (7) | −0.0023 (6) | −0.0011 (7) |
C6 | 0.0224 (8) | 0.0257 (8) | 0.0226 (8) | −0.0087 (7) | −0.0029 (6) | −0.0005 (6) |
C7 | 0.0249 (9) | 0.0241 (8) | 0.0314 (9) | −0.0090 (7) | −0.0038 (7) | 0.0043 (7) |
C8 | 0.0421 (11) | 0.0442 (12) | 0.0347 (10) | −0.0265 (10) | −0.0080 (9) | −0.0029 (9) |
C9 | 0.0269 (9) | 0.0285 (9) | 0.0305 (9) | −0.0135 (8) | −0.0053 (7) | 0.0065 (7) |
C10 | 0.0402 (11) | 0.0176 (8) | 0.0382 (10) | −0.0075 (7) | −0.0161 (8) | 0.0032 (7) |
C11 | 0.0386 (11) | 0.0415 (11) | 0.0495 (12) | −0.0279 (10) | −0.0090 (9) | 0.0086 (9) |
C12 | 0.0245 (9) | 0.0436 (11) | 0.0382 (11) | −0.0132 (8) | −0.0106 (8) | 0.0054 (9) |
Cl1—C9 | 1.739 (2) | C1—C6 | 1.412 (2) |
O1—C7 | 1.206 (2) | C1—C7 | 1.470 (2) |
O2—C2 | 1.372 (2) | C2—C3 | 1.390 (2) |
O2—C8 | 1.441 (2) | C3—C4 | 1.406 (2) |
O3—C4 | 1.352 (2) | C3—C9 | 1.479 (2) |
O3—C11 | 1.438 (2) | C4—C5 | 1.395 (3) |
O4—C6 | 1.358 (2) | C5—C6 | 1.392 (3) |
O4—C12 | 1.426 (2) | C9—C10 | 1.369 (3) |
C1—C2 | 1.412 (2) | ||
C2—O2—C8 | 114.04 (14) | O3—C4—C5 | 123.29 (16) |
C4—O3—C11 | 118.57 (15) | O3—C4—C3 | 115.46 (16) |
C6—O4—C12 | 118.37 (15) | C5—C4—C3 | 121.24 (16) |
C2—C1—C6 | 117.30 (15) | C6—C5—C4 | 118.80 (16) |
C2—C1—C7 | 124.03 (15) | O4—C6—C5 | 122.52 (16) |
C6—C1—C7 | 118.26 (15) | O4—C6—C1 | 115.53 (15) |
O2—C2—C3 | 116.62 (15) | C5—C6—C1 | 121.95 (16) |
O2—C2—C1 | 121.48 (15) | O1—C7—C1 | 126.65 (17) |
C3—C2—C1 | 121.83 (16) | C10—C9—C3 | 124.89 (17) |
C2—C3—C4 | 118.75 (16) | C10—C9—Cl1 | 119.62 (15) |
C2—C3—C9 | 120.49 (16) | C3—C9—Cl1 | 115.47 (14) |
C4—C3—C9 | 120.75 (15) | ||
C8—O2—C2—C3 | −109.77 (18) | O3—C4—C5—C6 | 179.93 (16) |
C8—O2—C2—C1 | 73.4 (2) | C3—C4—C5—C6 | 1.0 (3) |
C6—C1—C2—O2 | −179.08 (15) | C12—O4—C6—C5 | −6.6 (3) |
C7—C1—C2—O2 | 8.4 (3) | C12—O4—C6—C1 | 173.58 (16) |
C6—C1—C2—C3 | 4.2 (2) | C4—C5—C6—O4 | 179.52 (16) |
C7—C1—C2—C3 | −168.25 (16) | C4—C5—C6—C1 | −0.7 (3) |
O2—C2—C3—C4 | 179.21 (15) | C2—C1—C6—O4 | 177.95 (15) |
C1—C2—C3—C4 | −3.9 (3) | C7—C1—C6—O4 | −9.1 (2) |
O2—C2—C3—C9 | −1.5 (2) | C2—C1—C6—C5 | −1.9 (3) |
C1—C2—C3—C9 | 175.37 (16) | C7—C1—C6—C5 | 171.06 (16) |
C11—O3—C4—C5 | 0.6 (3) | C2—C1—C7—O1 | −5.8 (3) |
C11—O3—C4—C3 | 179.54 (17) | C6—C1—C7—O1 | −178.24 (19) |
C2—C3—C4—O3 | −177.75 (15) | C2—C3—C9—C10 | −103.1 (2) |
C9—C3—C4—O3 | 2.9 (2) | C4—C3—C9—C10 | 76.1 (2) |
C2—C3—C4—C5 | 1.2 (3) | C2—C3—C9—Cl1 | 75.24 (19) |
C9—C3—C4—C5 | −178.08 (16) | C4—C3—C9—Cl1 | −105.46 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12B···O1i | 0.98 | 2.48 | 2.998 (3) | 113 |
Symmetry code: (i) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C12H13ClO4 |
Mr | 256.67 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 180 |
a, b, c (Å) | 8.0516 (12), 8.1214 (12), 9.9064 (15) |
α, β, γ (°) | 88.427 (4), 86.171 (4), 67.868 (3) |
V (Å3) | 598.71 (15) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.32 |
Crystal size (mm) | 0.48 × 0.28 × 0.26 |
Data collection | |
Diffractometer | Siemens SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.862, 0.922 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3564, 2478, 2267 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.137, 1.10 |
No. of reflections | 2478 |
No. of parameters | 157 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.47, −0.71 |
Computer programs: SMART (Siemens, 1994), SAINT (Siemens, 1994), SAINT, SHELXTL/PC (Sheldrick, 1994), SHELXL97 (Sheldrick, 1997), SHELXTL/PC.
C8—O2—C2—C1 | 73.4 (2) | C2—C1—C7—O1 | −5.8 (3) |
C11—O3—C4—C5 | 0.6 (3) | C2—C3—C9—Cl1 | 75.24 (19) |
C12—O4—C6—C5 | −6.6 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12B···O1i | 0.98 | 2.48 | 2.998 (3) | 112.8 |
Symmetry code: (i) x−1, y, z. |
The Vilsmeier-Haack reaction, using disubstituted formamide and phosphorous oxychloride, has been extensively employed for the formylation of active aromatic rings yielding arylaldehydes (Minkin & Dorofeenko, 1960), of acetophenones yielding β-chloro-β-arylacroleins (Rosenblum et al., 1966) and of ortho-hydroxyacetophenones yielding chromon-3-carboxaldehydes (Nohara et al., 1974). β-Chloro β-arylacroleins have been a source for aryl acetylenes, which are useful for the synthesis of 2-arylbenzofurans (Duffley & Stevenson, 1977). In continuation with our work on synthesis of nor-neolignans (Parthasarathy & Mohakhud, 1995), we have investigated the formylation of phloracetophenone trimethyl ether, (III). Instead of the expected product, (I), we obtained a colourless crystalline compound, (II), whose 1H NMR spectrum did not show the expected coupling (J = 7 Hz) between the formyl proton and the α-olefinic 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 crystalline 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. \sch
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 aldehyde group at C1, are almost coplanar with the aromatic ring (the largest torsional deviation being less than 7°). In contrast, the torsion angles C8—O2—C2—C1 [73.4 (2)°] and C4—C3—C9—Cl1 [75.2 (2)°] (Table 1) illustrate the considerable twisting of the C2 methoxy and chlorovinyl substituents with respect to the aromatic ring.
The intermolecular forces responsible for the integrity of the crystal are of interest. The shortest separation between the centroids of aromatic rings is 4.12 Å and suggests that any intermolecular forces between these rings must be very weak. A detailed analysis of the shortest intermolecular atomic separations suggests that C—H.·O hydrogen bonding is likely to provide the major intermolecular forces. The O1.·C12(1 + x, y, z) separation of 2.998 (3) Å is about 0.22 Å less than the sum of the van der Waals radii of these two atoms (Bondi, 1964); this suggests a weak C12—H 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 refined as part of a rigid group, the derived C—H···O angle may not provide a reliable hydrogen-bonding parameter. The overall effect of these C—H.·O 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.