
Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807035106/fj2022sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536807035106/fj2022Isup2.hkl |
CCDC reference: 657851
(2E)-3-(1,3-Benzodioxol-5-yl)-1-(3-bromo-2-thienyl)prop-2-en-1-one(1.69 g, 5 mmol) and ethyl acetoacetate (0.65 g, 5 mmol) were refluxed for 4hrs in 20 ml e thanol in presence of 0.8 ml 10% NaOH. The reaction mixture was cooled to room temperature and the reaction mass was filtered and recrystallized using methanol. Crystals were grown from acetone. (Yield: 61%; m.p.: 391–393 K). Analysis for C20H17O5SBr: Found (Calculated): C: 53.34 (53.46%); H: 3.71 (3.81%); S: 7.09 (7.14%).
Attempts to refine the structure using a disordered model for the ethoxy group did not yield satisfactory results. H atoms were placed at calculated positions and refined riding on the respective carrier atom (Uiso(H)=1.2 Ueq of the respective carrier atom (1.5 for the methyl group), d(C—H) 0.93 Å(aromatic/olefinic C), 0.96 Å (CH3), 0.97 Å (CH2), 0.98 Å (tertiary CH).
Chalcones and the corresponding heterocyclic analogues are valuable intermediates in organic synthesis (Dhar, 1981) and exhibit a multitude of biological activities (Dimmock et al., 1999). An important feature of chalcones and their heteroanalogues is their ability to act as activated unsaturated systems in conjugated addition reactions of carbanions in the presence of basic catalysts (House, 1972). This type of reaction may be exploited for obtaining highly functionalized cyclohexene derivatives (Tabba et al., 1995), but is more commonly used for the preparation of 3,5-diaryl-6-carbethoxycyclohexanones via Michael addition of ethyl acetoacetate. The mentioned cyclohexenones are efficient synthons in building spiro compounds (Padmavathi, Sharmila, Somashekara Reddy et al., 2001) or as intermediates in the synthesis of benzisoxazoles or carbazole derivatives (Padmavathi et al., 1999; 2000, Padmavathi, Sharmila, Balaiah et al., 2001). In view of the importance of these derivatives, the title compound was synthesized and crystallized and the structure was determined.
The compound is prepared by the cyclocondensation of ethyl acetoacetate with (2E)-3-(1,3-benzodioxol-5-yl)-1-(3-bromo-2-thienyl)prop-2-en-1-one, which leads to the generation of two chiral centers at C7 and C8. As the reaction is not stereoselective, both configurations of the chiral carbon atoms are expected to be obtained, which would result in a mixture of diastereomers. No attempts to separate the diastereomers were undertaken and the crystals were grown from the mixture after recrystallization.
The geometry of the molecule is unexceptional. The dihedral angle between the phenyl ring and the thiophene group is 66.91 (13)°.
For related literature, see: Dhar (1981); Dimmock et al. (1999); House (1972); Padmavathi et al. (1999, 2000); Padmavathi, Sharmila, Balaiah et al. (2001); Padmavathi, Sharmila, Somashekara Reddy & Bhaskar Reddy (2001); Tabba et al. (1995).
Data collection: Collect (Nonius, 1999); cell refinement: DIRAX/LSQ (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2007).
![]() | Fig. 1. : The molecular structure of the title compound. Displacement ellipsoids are drawn at the 40% probability level. |
C20H17BrO5S | F(000) = 912 |
Mr = 449.32 | Dx = 1.572 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 123 reflections |
a = 17.3207 (12) Å | θ = 4.7–21.4° |
b = 11.8106 (9) Å | µ = 2.30 mm−1 |
c = 9.3661 (8) Å | T = 299 K |
β = 97.736 (7)° | Plate, colourless |
V = 1898.6 (3) Å3 | 0.35 × 0.30 × 0.20 mm |
Z = 4 |
Bruker–Nonius KappaCCD diffractometer | 2325 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.062 |
φ & ω scans | θmax = 25.5°, θmin = 4.6° |
Absorption correction: numerical (Herrendorf & Bärnighausen, 1997) | h = −20→20 |
Tmin = 0.593, Tmax = 0.851 | k = −14→14 |
17735 measured reflections | l = −11→11 |
3518 independent 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)] = 0.052 | H-atom parameters constrained |
wR(F2) = 0.118 | w = 1/[σ2(Fo2) + (0.0317P)2 + 2.7171P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max = 0.001 |
3518 reflections | Δρmax = 0.43 e Å−3 |
244 parameters | Δρmin = −0.47 e Å−3 |
0 restraints |
C20H17BrO5S | V = 1898.6 (3) Å3 |
Mr = 449.32 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 17.3207 (12) Å | µ = 2.30 mm−1 |
b = 11.8106 (9) Å | T = 299 K |
c = 9.3661 (8) Å | 0.35 × 0.30 × 0.20 mm |
β = 97.736 (7)° |
Bruker–Nonius KappaCCD diffractometer | 3518 independent reflections |
Absorption correction: numerical (Herrendorf & Bärnighausen, 1997) | 2325 reflections with I > 2σ(I) |
Tmin = 0.593, Tmax = 0.851 | Rint = 0.062 |
17735 measured reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.118 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.43 e Å−3 |
3518 reflections | Δρmin = −0.47 e Å−3 |
244 parameters |
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 > 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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.41565 (3) | 0.73085 (4) | 0.98853 (6) | 0.0749 (2) | |
S1 | 0.45442 (7) | 0.47034 (12) | 0.67283 (13) | 0.0646 (4) | |
C1 | 0.3593 (3) | 0.4947 (5) | 0.6816 (5) | 0.0695 (14) | |
H1 | 0.3189 | 0.4573 | 0.6251 | 0.083* | |
C2 | 0.3484 (3) | 0.5738 (4) | 0.7787 (5) | 0.0617 (12) | |
H2 | 0.2996 | 0.5973 | 0.7981 | 0.074* | |
C3 | 0.4187 (2) | 0.6175 (4) | 0.8480 (4) | 0.0499 (10) | |
C4 | 0.4839 (2) | 0.5705 (3) | 0.8045 (4) | 0.0461 (10) | |
C5 | 0.5671 (2) | 0.5879 (3) | 0.8476 (4) | 0.0433 (9) | |
C6 | 0.6226 (2) | 0.5372 (4) | 0.7523 (4) | 0.0464 (10) | |
H6A | 0.6277 | 0.5890 | 0.6738 | 0.056* | |
H6B | 0.6006 | 0.4671 | 0.7109 | 0.056* | |
C7 | 0.7037 (2) | 0.5131 (3) | 0.8346 (4) | 0.0432 (9) | |
H7 | 0.6972 | 0.4560 | 0.9081 | 0.052* | |
C8 | 0.7358 (2) | 0.6195 (3) | 0.9132 (4) | 0.0455 (10) | |
H8 | 0.7445 | 0.6770 | 0.8416 | 0.055* | |
C9 | 0.6785 (3) | 0.6662 (4) | 1.0076 (4) | 0.0536 (11) | |
C10 | 0.5963 (3) | 0.6454 (4) | 0.9659 (4) | 0.0533 (11) | |
H10 | 0.5616 | 0.6736 | 1.0247 | 0.064* | |
C11 | 0.7569 (2) | 0.4631 (3) | 0.7358 (4) | 0.0429 (9) | |
C12 | 0.7683 (3) | 0.3478 (4) | 0.7329 (5) | 0.0636 (13) | |
H12 | 0.7440 | 0.3024 | 0.7948 | 0.076* | |
C13 | 0.8144 (3) | 0.2966 (4) | 0.6417 (6) | 0.0769 (15) | |
H13 | 0.8203 | 0.2184 | 0.6394 | 0.092* | |
C14 | 0.8505 (3) | 0.3653 (4) | 0.5561 (5) | 0.0589 (12) | |
C15 | 0.8405 (2) | 0.4800 (4) | 0.5584 (5) | 0.0524 (11) | |
C16 | 0.7948 (2) | 0.5316 (4) | 0.6461 (5) | 0.0518 (11) | |
H16 | 0.7891 | 0.6098 | 0.6462 | 0.062* | |
C17 | 0.9153 (4) | 0.4379 (5) | 0.3900 (6) | 0.0843 (16) | |
H17A | 0.8902 | 0.4358 | 0.2910 | 0.101* | |
H17B | 0.9709 | 0.4474 | 0.3894 | 0.101* | |
C18 | 0.8121 (3) | 0.5959 (4) | 1.0062 (5) | 0.0572 (12) | |
C19 | 0.9454 (5) | 0.6571 (8) | 1.0697 (8) | 0.140 (3) | |
H19A | 0.9557 | 0.5770 | 1.0852 | 0.169* | |
H19B | 0.9842 | 0.6890 | 1.0157 | 0.169* | |
C20 | 0.9437 (5) | 0.7139 (8) | 1.1993 (10) | 0.143 (3) | |
H20A | 0.9317 | 0.7923 | 1.1803 | 0.215* | |
H20B | 0.9936 | 0.7078 | 1.2572 | 0.215* | |
H20C | 0.9046 | 0.6809 | 1.2499 | 0.215* | |
O1 | 0.7014 (2) | 0.7217 (3) | 1.1149 (4) | 0.0782 (10) | |
O2 | 0.86292 (19) | 0.6774 (3) | 0.9936 (4) | 0.0848 (11) | |
O3 | 0.8237 (2) | 0.5135 (3) | 1.0799 (4) | 0.0757 (10) | |
O4 | 0.8855 (2) | 0.5292 (3) | 0.4645 (4) | 0.0907 (12) | |
O5 | 0.9007 (2) | 0.3362 (3) | 0.4610 (4) | 0.0807 (11) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0724 (4) | 0.0617 (3) | 0.0943 (4) | 0.0033 (3) | 0.0245 (3) | −0.0144 (3) |
S1 | 0.0488 (7) | 0.0880 (9) | 0.0555 (7) | −0.0104 (6) | 0.0022 (5) | −0.0191 (7) |
C1 | 0.047 (3) | 0.092 (4) | 0.066 (3) | −0.013 (3) | −0.003 (2) | −0.004 (3) |
C2 | 0.048 (3) | 0.072 (3) | 0.066 (3) | 0.002 (2) | 0.010 (2) | 0.014 (3) |
C3 | 0.050 (3) | 0.048 (3) | 0.052 (2) | −0.001 (2) | 0.010 (2) | 0.010 (2) |
C4 | 0.043 (2) | 0.050 (2) | 0.045 (2) | −0.005 (2) | 0.0039 (18) | 0.008 (2) |
C5 | 0.049 (2) | 0.044 (2) | 0.038 (2) | −0.0057 (19) | 0.0074 (18) | 0.0036 (19) |
C6 | 0.043 (2) | 0.050 (3) | 0.045 (2) | −0.0074 (19) | 0.0019 (18) | −0.007 (2) |
C7 | 0.044 (2) | 0.043 (2) | 0.042 (2) | −0.0074 (18) | 0.0034 (17) | 0.0012 (18) |
C8 | 0.046 (2) | 0.044 (2) | 0.044 (2) | −0.0114 (19) | −0.0023 (18) | 0.0003 (19) |
C9 | 0.065 (3) | 0.047 (3) | 0.047 (2) | −0.014 (2) | 0.001 (2) | −0.006 (2) |
C10 | 0.057 (3) | 0.057 (3) | 0.048 (2) | −0.006 (2) | 0.013 (2) | −0.007 (2) |
C11 | 0.036 (2) | 0.048 (2) | 0.043 (2) | −0.0083 (18) | −0.0022 (17) | −0.0015 (19) |
C12 | 0.073 (3) | 0.046 (3) | 0.074 (3) | −0.004 (2) | 0.016 (3) | 0.004 (2) |
C13 | 0.087 (4) | 0.053 (3) | 0.094 (4) | 0.008 (3) | 0.022 (3) | −0.001 (3) |
C14 | 0.051 (3) | 0.063 (3) | 0.062 (3) | 0.014 (2) | 0.004 (2) | −0.004 (2) |
C15 | 0.045 (2) | 0.058 (3) | 0.055 (3) | 0.001 (2) | 0.007 (2) | 0.009 (2) |
C16 | 0.053 (3) | 0.041 (2) | 0.060 (3) | 0.004 (2) | 0.008 (2) | 0.000 (2) |
C17 | 0.083 (4) | 0.096 (5) | 0.077 (4) | 0.018 (3) | 0.022 (3) | −0.007 (3) |
C18 | 0.054 (3) | 0.058 (3) | 0.056 (3) | −0.015 (2) | −0.002 (2) | −0.004 (2) |
C19 | 0.128 (6) | 0.183 (8) | 0.100 (5) | −0.103 (6) | −0.023 (5) | 0.004 (6) |
C20 | 0.102 (6) | 0.174 (9) | 0.152 (8) | 0.012 (6) | 0.013 (5) | 0.040 (7) |
O1 | 0.077 (2) | 0.089 (3) | 0.069 (2) | −0.028 (2) | 0.0101 (18) | −0.037 (2) |
O2 | 0.060 (2) | 0.086 (3) | 0.100 (3) | −0.036 (2) | −0.0207 (19) | 0.017 (2) |
O3 | 0.077 (2) | 0.064 (2) | 0.077 (2) | −0.0126 (18) | −0.0220 (18) | 0.0174 (19) |
O4 | 0.107 (3) | 0.074 (3) | 0.103 (3) | 0.013 (2) | 0.057 (2) | 0.006 (2) |
O5 | 0.083 (3) | 0.078 (3) | 0.087 (2) | 0.026 (2) | 0.030 (2) | −0.004 (2) |
Br1—C3 | 1.883 (4) | C11—C16 | 1.393 (5) |
S1—C1 | 1.686 (5) | C12—C13 | 1.385 (7) |
S1—C4 | 1.736 (4) | C12—H12 | 0.9300 |
C1—C2 | 1.335 (7) | C13—C14 | 1.352 (7) |
C1—H1 | 0.9300 | C13—H13 | 0.9300 |
C2—C3 | 1.398 (6) | C14—C15 | 1.365 (6) |
C2—H2 | 0.9300 | C14—O5 | 1.370 (5) |
C3—C4 | 1.369 (6) | C15—C16 | 1.359 (6) |
C4—C5 | 1.458 (5) | C15—O4 | 1.379 (5) |
C5—C10 | 1.339 (5) | C16—H16 | 0.9300 |
C5—C6 | 1.519 (5) | C17—O5 | 1.413 (7) |
C6—C7 | 1.535 (5) | C17—O4 | 1.420 (6) |
C6—H6A | 0.9700 | C17—H17A | 0.9700 |
C6—H6B | 0.9700 | C17—H17B | 0.9700 |
C7—C11 | 1.512 (5) | C18—O3 | 1.194 (5) |
C7—C8 | 1.523 (5) | C18—O2 | 1.321 (5) |
C7—H7 | 0.9800 | C19—C20 | 1.391 (10) |
C8—C18 | 1.508 (6) | C19—O2 | 1.527 (8) |
C8—C9 | 1.518 (6) | C19—H19A | 0.9700 |
C8—H8 | 0.9800 | C19—H19B | 0.9700 |
C9—O1 | 1.221 (5) | C20—H20A | 0.9600 |
C9—C10 | 1.445 (6) | C20—H20B | 0.9600 |
C10—H10 | 0.9300 | C20—H20C | 0.9600 |
C11—C12 | 1.377 (6) | ||
C1—S1—C4 | 92.6 (2) | C12—C11—C7 | 119.9 (4) |
C2—C1—S1 | 112.4 (4) | C16—C11—C7 | 121.3 (4) |
C2—C1—H1 | 123.8 | C11—C12—C13 | 122.7 (5) |
S1—C1—H1 | 123.8 | C11—C12—H12 | 118.7 |
C1—C2—C3 | 112.4 (4) | C13—C12—H12 | 118.7 |
C1—C2—H2 | 123.8 | C14—C13—C12 | 117.1 (5) |
C3—C2—H2 | 123.8 | C14—C13—H13 | 121.5 |
C4—C3—C2 | 114.5 (4) | C12—C13—H13 | 121.5 |
C4—C3—Br1 | 126.7 (3) | C13—C14—C15 | 121.1 (5) |
C2—C3—Br1 | 118.8 (3) | C13—C14—O5 | 128.3 (5) |
C3—C4—C5 | 133.3 (4) | C15—C14—O5 | 110.6 (4) |
C3—C4—S1 | 108.2 (3) | C16—C15—C14 | 122.6 (4) |
C5—C4—S1 | 118.6 (3) | C16—C15—O4 | 128.4 (4) |
C10—C5—C4 | 123.3 (4) | C14—C15—O4 | 108.9 (4) |
C10—C5—C6 | 119.2 (4) | C15—C16—C11 | 117.7 (4) |
C4—C5—C6 | 117.5 (3) | C15—C16—H16 | 121.2 |
C5—C6—C7 | 112.7 (3) | C11—C16—H16 | 121.2 |
C5—C6—H6A | 109.0 | O5—C17—O4 | 108.3 (4) |
C7—C6—H6A | 109.0 | O5—C17—H17A | 110.0 |
C5—C6—H6B | 109.0 | O4—C17—H17A | 110.0 |
C7—C6—H6B | 109.0 | O5—C17—H17B | 110.0 |
H6A—C6—H6B | 107.8 | O4—C17—H17B | 110.0 |
C11—C7—C8 | 113.9 (3) | H17A—C17—H17B | 108.4 |
C11—C7—C6 | 110.9 (3) | O3—C18—O2 | 125.7 (4) |
C8—C7—C6 | 109.9 (3) | O3—C18—C8 | 123.4 (4) |
C11—C7—H7 | 107.3 | O2—C18—C8 | 110.9 (4) |
C8—C7—H7 | 107.3 | C20—C19—O2 | 101.7 (8) |
C6—C7—H7 | 107.3 | C20—C19—H19A | 111.4 |
C18—C8—C9 | 108.8 (3) | O2—C19—H19A | 111.4 |
C18—C8—C7 | 111.1 (3) | C20—C19—H19B | 111.4 |
C9—C8—C7 | 110.8 (3) | O2—C19—H19B | 111.4 |
C18—C8—H8 | 108.7 | H19A—C19—H19B | 109.3 |
C9—C8—H8 | 108.7 | C19—C20—H20A | 109.5 |
C7—C8—H8 | 108.7 | C19—C20—H20B | 109.5 |
O1—C9—C10 | 120.9 (4) | H20A—C20—H20B | 109.5 |
O1—C9—C8 | 120.5 (4) | C19—C20—H20C | 109.5 |
C10—C9—C8 | 118.6 (4) | H20A—C20—H20C | 109.5 |
C5—C10—C9 | 123.9 (4) | H20B—C20—H20C | 109.5 |
C5—C10—H10 | 118.0 | C18—O2—C19 | 115.9 (5) |
C9—C10—H10 | 118.0 | C15—O4—C17 | 105.5 (4) |
C12—C11—C16 | 118.8 (4) | C14—O5—C17 | 105.2 (4) |
Experimental details
Crystal data | |
Chemical formula | C20H17BrO5S |
Mr | 449.32 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 299 |
a, b, c (Å) | 17.3207 (12), 11.8106 (9), 9.3661 (8) |
β (°) | 97.736 (7) |
V (Å3) | 1898.6 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.30 |
Crystal size (mm) | 0.35 × 0.30 × 0.20 |
Data collection | |
Diffractometer | Bruker–Nonius KappaCCD |
Absorption correction | Numerical (Herrendorf & Bärnighausen, 1997) |
Tmin, Tmax | 0.593, 0.851 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 17735, 3518, 2325 |
Rint | 0.062 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.118, 1.11 |
No. of reflections | 3518 |
No. of parameters | 244 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.43, −0.47 |
Computer programs: Collect (Nonius, 1999), DIRAX/LSQ (Duisenberg, 1992), EVALCCD (Duisenberg et al., 2003), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2007).
Chalcones and the corresponding heterocyclic analogues are valuable intermediates in organic synthesis (Dhar, 1981) and exhibit a multitude of biological activities (Dimmock et al., 1999). An important feature of chalcones and their heteroanalogues is their ability to act as activated unsaturated systems in conjugated addition reactions of carbanions in the presence of basic catalysts (House, 1972). This type of reaction may be exploited for obtaining highly functionalized cyclohexene derivatives (Tabba et al., 1995), but is more commonly used for the preparation of 3,5-diaryl-6-carbethoxycyclohexanones via Michael addition of ethyl acetoacetate. The mentioned cyclohexenones are efficient synthons in building spiro compounds (Padmavathi, Sharmila, Somashekara Reddy et al., 2001) or as intermediates in the synthesis of benzisoxazoles or carbazole derivatives (Padmavathi et al., 1999; 2000, Padmavathi, Sharmila, Balaiah et al., 2001). In view of the importance of these derivatives, the title compound was synthesized and crystallized and the structure was determined.
The compound is prepared by the cyclocondensation of ethyl acetoacetate with (2E)-3-(1,3-benzodioxol-5-yl)-1-(3-bromo-2-thienyl)prop-2-en-1-one, which leads to the generation of two chiral centers at C7 and C8. As the reaction is not stereoselective, both configurations of the chiral carbon atoms are expected to be obtained, which would result in a mixture of diastereomers. No attempts to separate the diastereomers were undertaken and the crystals were grown from the mixture after recrystallization.
The geometry of the molecule is unexceptional. The dihedral angle between the phenyl ring and the thiophene group is 66.91 (13)°.