organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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9-Isopropenyl-4-methyl-2H-thieno[2,3-h]chromen-2-one

aDepartment of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai 200032, People's Republic of China
*Correspondence e-mail: pxia@fudan.edu.cn

(Received 11 May 2009; accepted 12 May 2009; online 20 May 2009)

The title compound, C15H12O2S, features three fused rings with a dihedral angle of 79.6 (2)° between the isopropenyl group and the thio­phene ring. In the crystal, mol­ecules are connected into a supra­molecular helical chain via C—H⋯O contacts.

Related literature

The title compound was obtained unexpectedly during an attempt to prepare 4-methyl-7-(2-methyl­but-3-yn-2-ylthio)-2H-chromen-2-one, a key inter­mediate in our study of the synthesis of potential anti-HIV heterocyclic agents (Chen et al., 2004[Chen, Y., Zhang, Q., Zhang, B., Xia, P., Xia, Y., Yang, Z., Kilgore, N., Wild, C., Morris-Natschke, S. L. & Lee, K. (2004). Bioorg. Med. Chem. 12, 6383-6387.])

[Scheme 1]

Experimental

Crystal data
  • C15H12O2S

  • Mr = 256.31

  • Monoclinic, P 21 /c

  • a = 8.547 (2) Å

  • b = 11.425 (3) Å

  • c = 13.641 (4) Å

  • β = 108.259 (19)°

  • V = 1265.0 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.25 mm−1

  • T = 293 K

  • 0.50 × 0.15 × 0.12 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.887, Tmax = 0.971

  • 5816 measured reflections

  • 2698 independent reflections

  • 1870 reflections with I > 2σ(I)

  • Rint = 0.091

Refinement
  • R[F2 > 2σ(F2)] = 0.068

  • wR(F2) = 0.177

  • S = 0.99

  • 2698 reflections

  • 166 parameters

  • H-atom parameters constrained

  • Δρmax = 0.37 e Å−3

  • Δρmin = −0.44 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C11—H11⋯O2i 0.93 2.44 3.293 (3) 153
Symmetry code: (i) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

4-Methyl-7-(2-methylbut-3-yn-2-ylthio)-2H-chromen-2-one is a key intermediate in our study on synthesizing potential anti-HIV heterocyclic agents (Chen et al., 2004). We attempted to prepare this by the reaction of 7-mercapto-4-methyl-2H-chromen-2-one with 2-methylbut-3-yn-2-ol in the presence of a catalytic amount of p-toluenesulphonate in refluxing toluene. To our surprise, an unexpected product (I) was obtained, which was structurally characterized by 1H NMR, MS, HRMS. The molecular structure was confirmed by X-ray diffraction. The determination of the structure of (I) is important for discovering the mechanism of this unexpected reaction. The full structural details of (I) are reported herein.

The molecular structure of (I), Fig. 1, shows three fused rings. The C10–C11 and C12-C13 bond distances of 1.351 (3) and 1.328 (4) Å, respectively indicate typical C=C double bonds. The isopropenyl group and the thiophene ring make a dihedral angle of 79.6 (2)°, due to the charge repulsion between π-electrons of isopropenyl group and the lactone-oxygen lone pair of electron lactone as well as unfavourable steric interactions. The molecular packing is stabilized by C—H···O contacts that link molecules into a supramolecular helical chain along the b-axis (Table 1).

Related literature top

The title compound was obtained unexpectedly during an attempt to prepare 4-methyl-7-(2-methylbut-3-yn-2-ylthio)-2H-chromen-2-one, a key intermediate in our study on the synthesis of potential anti-HIV heterocyclic agents (Chen et al., 2004)

Experimental top

A mixture of 7-mercapto-4-methyl-2H-chromen-2-one (961 mg, 5 mmol), 2-methylbut-3-yn-2-ol (6 ml, 60 mmol) and pyridinium p-toluenesulphonate (90 mg, 0.36 mmol) in dry toluene (30 ml) was refluxed for 6 h. After the toluene was evaporated in vacuo, the residue was purified by silica gel column chromatography (petroleum ether / acetone = 15 / 1) to afford 260 mg of (I); yield 21.3%. Recrystallization from isopropyl ether gave colourless crystals.

Refinement top

All H atoms were placed in the idealized positions with C—H = 0.93— 0.96 Å, and with Uiso(H) = 1.2—1.5 Ueq(C).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms.
9-Isopropenyl-4-methyl-2H-thieno[2,3-h]chromen-2-one top
Crystal data top
C15H12O2SF(000) = 536
Mr = 256.31Dx = 1.346 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 812 reflections
a = 8.547 (2) Åθ = 3.1–27.4°
b = 11.425 (3) ŵ = 0.25 mm1
c = 13.641 (4) ÅT = 293 K
β = 108.259 (19)°Block, yellow
V = 1265.0 (6) Å30.50 × 0.15 × 0.12 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
2698 independent reflections
Radiation source: fine-focus sealed tube1870 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.091
ϕ and ω scansθmax = 27.0°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1010
Tmin = 0.887, Tmax = 0.971k = 1114
5816 measured reflectionsl = 1417
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.068H-atom parameters constrained
wR(F2) = 0.177 w = 1/[σ2(Fo2) + (0.1022P)2P]
where P = (Fo2 + 2Fc2)/3
S = 0.99(Δ/σ)max < 0.001
2698 reflectionsΔρmax = 0.37 e Å3
166 parametersΔρmin = 0.44 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.021 (5)
Crystal data top
C15H12O2SV = 1265.0 (6) Å3
Mr = 256.31Z = 4
Monoclinic, P21/cMo Kα radiation
a = 8.547 (2) ŵ = 0.25 mm1
b = 11.425 (3) ÅT = 293 K
c = 13.641 (4) Å0.50 × 0.15 × 0.12 mm
β = 108.259 (19)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
2698 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1870 reflections with I > 2σ(I)
Tmin = 0.887, Tmax = 0.971Rint = 0.091
5816 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0680 restraints
wR(F2) = 0.177H-atom parameters constrained
S = 0.99Δρmax = 0.37 e Å3
2698 reflectionsΔρmin = 0.44 e Å3
166 parameters
Special details top

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) top
xyzUiso*/Ueq
S10.97805 (8)0.09812 (6)0.19803 (5)0.0637 (3)
O10.65111 (17)0.10433 (13)0.38658 (11)0.0495 (4)
O20.4812 (2)0.18035 (18)0.46125 (14)0.0719 (6)
C10.6213 (3)0.1761 (2)0.45948 (18)0.0526 (6)
C20.7579 (3)0.2386 (2)0.52571 (17)0.0563 (6)
H20.74010.28920.57450.068*
C30.9108 (3)0.22726 (19)0.52044 (17)0.0486 (6)
C40.9398 (3)0.14773 (18)0.44540 (15)0.0411 (5)
C51.0960 (3)0.12728 (19)0.43491 (17)0.0464 (5)
H51.18720.16500.47930.056*
C61.1173 (3)0.0535 (2)0.36125 (17)0.0498 (6)
H61.22130.04070.35520.060*
C70.9796 (3)0.0016 (2)0.29585 (16)0.0457 (5)
C80.8207 (2)0.01396 (19)0.30220 (15)0.0431 (5)
C90.8056 (3)0.09080 (17)0.37904 (16)0.0415 (5)
C100.6986 (3)0.0519 (2)0.22558 (17)0.0520 (6)
C110.7694 (3)0.1131 (2)0.1659 (2)0.0627 (7)
H110.70890.15980.11140.075*
C120.5195 (3)0.0597 (2)0.21115 (19)0.0587 (7)
C130.4143 (4)0.0004 (4)0.1349 (3)0.1030 (12)
H13A0.30150.00750.12330.124*
H13B0.45340.04840.09310.124*
C140.4693 (4)0.1369 (3)0.2794 (3)0.0912 (10)
H14A0.35120.13770.26050.137*
H14B0.51470.10990.34920.137*
H14C0.50840.21460.27380.137*
C151.0528 (3)0.2947 (2)0.5901 (2)0.0675 (8)
H15A1.01570.34000.63780.101*
H15B1.09670.34600.54960.101*
H15C1.13690.24120.62770.101*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0501 (5)0.0779 (5)0.0685 (5)0.0039 (3)0.0261 (4)0.0209 (3)
O10.0338 (9)0.0599 (10)0.0531 (9)0.0017 (7)0.0113 (7)0.0063 (7)
O20.0453 (11)0.0963 (14)0.0778 (12)0.0071 (9)0.0246 (10)0.0110 (10)
C10.0417 (14)0.0603 (14)0.0555 (13)0.0080 (11)0.0149 (11)0.0032 (11)
C20.0582 (16)0.0567 (14)0.0545 (13)0.0085 (12)0.0184 (12)0.0063 (11)
C30.0488 (14)0.0448 (12)0.0494 (12)0.0008 (10)0.0114 (11)0.0021 (10)
C40.0392 (12)0.0405 (10)0.0426 (10)0.0018 (9)0.0112 (9)0.0036 (9)
C50.0368 (12)0.0475 (11)0.0524 (12)0.0077 (10)0.0102 (10)0.0029 (10)
C60.0350 (12)0.0567 (13)0.0595 (13)0.0025 (11)0.0177 (10)0.0033 (11)
C70.0408 (12)0.0519 (12)0.0465 (11)0.0004 (10)0.0168 (10)0.0007 (10)
C80.0358 (11)0.0476 (12)0.0450 (11)0.0003 (9)0.0112 (10)0.0023 (9)
C90.0339 (12)0.0459 (11)0.0453 (11)0.0026 (9)0.0134 (10)0.0059 (9)
C100.0409 (13)0.0607 (14)0.0498 (12)0.0034 (11)0.0078 (10)0.0060 (11)
C110.0472 (15)0.0769 (17)0.0603 (14)0.0012 (12)0.0114 (12)0.0201 (13)
C120.0366 (13)0.0708 (16)0.0617 (14)0.0009 (12)0.0054 (12)0.0187 (13)
C130.0510 (18)0.118 (3)0.121 (3)0.0160 (19)0.0002 (18)0.019 (2)
C140.0461 (17)0.118 (3)0.111 (2)0.0068 (18)0.0273 (18)0.012 (2)
C150.0649 (18)0.0664 (16)0.0681 (16)0.0130 (13)0.0165 (14)0.0224 (13)
Geometric parameters (Å, º) top
S1—C111.706 (3)C7—C81.399 (3)
S1—C71.728 (2)C8—C91.404 (3)
O1—C91.365 (2)C8—C101.437 (3)
O1—C11.373 (3)C10—C111.351 (3)
O2—C11.205 (3)C10—C121.484 (3)
C1—C21.424 (3)C11—H110.9300
C2—C31.338 (3)C12—C131.328 (4)
C2—H20.9300C12—C141.442 (4)
C3—C41.447 (3)C13—H13A0.9300
C3—C151.499 (3)C13—H13B0.9300
C4—C91.381 (3)C14—H14A0.9600
C4—C51.406 (3)C14—H14B0.9600
C5—C61.367 (3)C14—H14C0.9600
C5—H50.9300C15—H15A0.9600
C6—C71.385 (3)C15—H15B0.9600
C6—H60.9300C15—H15C0.9600
C11—S1—C790.94 (11)O1—C9—C8116.39 (18)
C9—O1—C1121.72 (17)C4—C9—C8122.13 (19)
O2—C1—O1116.7 (2)C11—C10—C8110.4 (2)
O2—C1—C2126.1 (2)C11—C10—C12121.8 (2)
O1—C1—C2117.21 (19)C8—C10—C12127.7 (2)
C3—C2—C1122.6 (2)C10—C11—S1115.0 (2)
C3—C2—H2118.7C10—C11—H11122.5
C1—C2—H2118.7S1—C11—H11122.5
C2—C3—C4119.1 (2)C13—C12—C14123.5 (3)
C2—C3—C15121.8 (2)C13—C12—C10119.4 (3)
C4—C3—C15119.1 (2)C14—C12—C10117.0 (2)
C9—C4—C5118.38 (19)C12—C13—H13A120.0
C9—C4—C3117.90 (19)C12—C13—H13B120.0
C5—C4—C3123.7 (2)H13A—C13—H13B120.0
C6—C5—C4121.8 (2)C12—C14—H14A109.5
C6—C5—H5119.1C12—C14—H14B109.5
C4—C5—H5119.1H14A—C14—H14B109.5
C5—C6—C7118.1 (2)C12—C14—H14C109.5
C5—C6—H6120.9H14A—C14—H14C109.5
C7—C6—H6120.9H14B—C14—H14C109.5
C6—C7—C8123.2 (2)C3—C15—H15A109.5
C6—C7—S1125.92 (17)C3—C15—H15B109.5
C8—C7—S1110.87 (16)H15A—C15—H15B109.5
C7—C8—C9116.35 (19)C3—C15—H15C109.5
C7—C8—C10112.72 (19)H15A—C15—H15C109.5
C9—C8—C10130.9 (2)H15B—C15—H15C109.5
O1—C9—C4121.46 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C11—H11···O2i0.932.443.293 (3)153
Symmetry code: (i) x+1, y1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC15H12O2S
Mr256.31
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)8.547 (2), 11.425 (3), 13.641 (4)
β (°) 108.259 (19)
V3)1265.0 (6)
Z4
Radiation typeMo Kα
µ (mm1)0.25
Crystal size (mm)0.50 × 0.15 × 0.12
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.887, 0.971
No. of measured, independent and
observed [I > 2σ(I)] reflections
5816, 2698, 1870
Rint0.091
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.068, 0.177, 0.99
No. of reflections2698
No. of parameters166
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.37, 0.44

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C11—H11···O2i0.932.443.293 (3)153
Symmetry code: (i) x+1, y1/2, z+1/2.
 

Acknowledgements

The authors acknowledge Professor Linhong Weng for fruitful discussions and the Department of Chemistry, Fudan University, for providing necessary facilities.

References

First citationBruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChen, Y., Zhang, Q., Zhang, B., Xia, P., Xia, Y., Yang, Z., Kilgore, N., Wild, C., Morris-Natschke, S. L. & Lee, K. (2004). Bioorg. Med. Chem. 12, 6383–6387.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
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