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

Xu, S.; Chen, Y.; Xia, P.

doi:10.1107/S1600536809017930

organic compounds

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ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page o1311

doi:10.1107/S1600536809017930

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

Shiqing Xu,^a Ying Chen ^a and Peng Xia ^a ^*

^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 )

Experimental

Crystal data

C₁₅H₁₂O₂S
M_r = 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 ) T_min = 0.887, T_max = 0.971
5816 measured reflections
2698 independent reflections
1870 reflections with I > 2σ(I)
R_int = 0.091

Refinement

R[F² > 2σ(F²)] = 0.068
wR(F²) = 0.177
S = 0.99
2698 reflections
166 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.44 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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 ); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809017930/tk2449sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809017930/tk2449Isup2.hkl

checkCIF report

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.

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

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

C₁₅H₁₂O₂S	F(000) = 536
M_r = 256.31	D_x = 1.346 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 812 reflections
a = 8.547 (2) Å	θ = 3.1–27.4°
b = 11.425 (3) Å	µ = 0.25 mm⁻¹
c = 13.641 (4) Å	T = 293 K
β = 108.259 (19)°	Block, yellow
V = 1265.0 (6) Å³	0.50 × 0.15 × 0.12 mm
Z = 4

Data collection top

Bruker SMART CCD area-detector diffractometer	2698 independent reflections
Radiation source: fine-focus sealed tube	1870 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.091
ϕ and ω scans	θ_max = 27.0°, θ_min = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
T_min = 0.887, T_max = 0.971	k = −11→14
5816 measured reflections	l = −14→17

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.068	H-atom parameters constrained
wR(F²) = 0.177	w = 1/[σ²(F_o²) + (0.1022P)²P] where P = (F_o² + 2F_c²)/3
S = 0.99	(Δ/σ)_max < 0.001
2698 reflections	Δρ_max = 0.37 e Å⁻³
166 parameters	Δρ_min = −0.44 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.021 (5)

Crystal data top

C₁₅H₁₂O₂S	V = 1265.0 (6) Å³
M_r = 256.31	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 8.547 (2) Å	µ = 0.25 mm⁻¹
b = 11.425 (3) Å	T = 293 K
c = 13.641 (4) Å	0.50 × 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)
T_min = 0.887, T_max = 0.971	R_int = 0.091
5816 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.068	0 restraints
wR(F²) = 0.177	H-atom parameters constrained
S = 0.99	Δρ_max = 0.37 e Å⁻³
2698 reflections	Δρ_min = −0.44 e Å⁻³
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

	x	y	z	U_iso*/U_eq
S1	0.97805 (8)	−0.09812 (6)	0.19803 (5)	0.0637 (3)
O1	0.65111 (17)	0.10433 (13)	0.38658 (11)	0.0495 (4)
O2	0.4812 (2)	0.18035 (18)	0.46125 (14)	0.0719 (6)
C1	0.6213 (3)	0.1761 (2)	0.45948 (18)	0.0526 (6)
C2	0.7579 (3)	0.2386 (2)	0.52571 (17)	0.0563 (6)
H2	0.7401	0.2892	0.5745	0.068*
C3	0.9108 (3)	0.22726 (19)	0.52044 (17)	0.0486 (6)
C4	0.9398 (3)	0.14773 (18)	0.44540 (15)	0.0411 (5)
C5	1.0960 (3)	0.12728 (19)	0.43491 (17)	0.0464 (5)
H5	1.1872	0.1650	0.4793	0.056*
C6	1.1173 (3)	0.0535 (2)	0.36125 (17)	0.0498 (6)
H6	1.2213	0.0407	0.3552	0.060*
C7	0.9796 (3)	−0.0016 (2)	0.29585 (16)	0.0457 (5)
C8	0.8207 (2)	0.01396 (19)	0.30220 (15)	0.0431 (5)
C9	0.8056 (3)	0.09080 (17)	0.37904 (16)	0.0415 (5)
C10	0.6986 (3)	−0.0519 (2)	0.22558 (17)	0.0520 (6)
C11	0.7694 (3)	−0.1131 (2)	0.1659 (2)	0.0627 (7)
H11	0.7089	−0.1598	0.1114	0.075*
C12	0.5195 (3)	−0.0597 (2)	0.21115 (19)	0.0587 (7)
C13	0.4143 (4)	−0.0004 (4)	0.1349 (3)	0.1030 (12)
H13A	0.3015	−0.0075	0.1233	0.124*
H13B	0.4534	0.0484	0.0931	0.124*
C14	0.4693 (4)	−0.1369 (3)	0.2794 (3)	0.0912 (10)
H14A	0.3512	−0.1377	0.2605	0.137*
H14B	0.5147	−0.1099	0.3492	0.137*
H14C	0.5084	−0.2146	0.2738	0.137*
C15	1.0528 (3)	0.2947 (2)	0.5901 (2)	0.0675 (8)
H15A	1.0157	0.3400	0.6378	0.101*
H15B	1.0967	0.3460	0.5496	0.101*
H15C	1.1369	0.2412	0.6277	0.101*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0501 (5)	0.0779 (5)	0.0685 (5)	−0.0039 (3)	0.0261 (4)	−0.0209 (3)
O1	0.0338 (9)	0.0599 (10)	0.0531 (9)	0.0017 (7)	0.0113 (7)	−0.0063 (7)
O2	0.0453 (11)	0.0963 (14)	0.0778 (12)	0.0071 (9)	0.0246 (10)	−0.0110 (10)
C1	0.0417 (14)	0.0603 (14)	0.0555 (13)	0.0080 (11)	0.0149 (11)	0.0032 (11)
C2	0.0582 (16)	0.0567 (14)	0.0545 (13)	0.0085 (12)	0.0184 (12)	−0.0063 (11)
C3	0.0488 (14)	0.0448 (12)	0.0494 (12)	0.0008 (10)	0.0114 (11)	0.0021 (10)
C4	0.0392 (12)	0.0405 (10)	0.0426 (10)	−0.0018 (9)	0.0112 (9)	0.0036 (9)
C5	0.0368 (12)	0.0475 (11)	0.0524 (12)	−0.0077 (10)	0.0102 (10)	0.0029 (10)
C6	0.0350 (12)	0.0567 (13)	0.0595 (13)	−0.0025 (11)	0.0177 (10)	0.0033 (11)
C7	0.0408 (12)	0.0519 (12)	0.0465 (11)	−0.0004 (10)	0.0168 (10)	0.0007 (10)
C8	0.0358 (11)	0.0476 (12)	0.0450 (11)	0.0003 (9)	0.0112 (10)	0.0023 (9)
C9	0.0339 (12)	0.0459 (11)	0.0453 (11)	0.0026 (9)	0.0134 (10)	0.0059 (9)
C10	0.0409 (13)	0.0607 (14)	0.0498 (12)	0.0034 (11)	0.0078 (10)	−0.0060 (11)
C11	0.0472 (15)	0.0769 (17)	0.0603 (14)	0.0012 (12)	0.0114 (12)	−0.0201 (13)
C12	0.0366 (13)	0.0708 (16)	0.0617 (14)	0.0009 (12)	0.0054 (12)	−0.0187 (13)
C13	0.0510 (18)	0.118 (3)	0.121 (3)	0.0160 (19)	−0.0002 (18)	0.019 (2)
C14	0.0461 (17)	0.118 (3)	0.111 (2)	−0.0068 (18)	0.0273 (18)	0.012 (2)
C15	0.0649 (18)	0.0664 (16)	0.0681 (16)	−0.0130 (13)	0.0165 (14)	−0.0224 (13)

Geometric parameters (Å, º) top

S1—C11	1.706 (3)	C7—C8	1.399 (3)
S1—C7	1.728 (2)	C8—C9	1.404 (3)
O1—C9	1.365 (2)	C8—C10	1.437 (3)
O1—C1	1.373 (3)	C10—C11	1.351 (3)
O2—C1	1.205 (3)	C10—C12	1.484 (3)
C1—C2	1.424 (3)	C11—H11	0.9300
C2—C3	1.338 (3)	C12—C13	1.328 (4)
C2—H2	0.9300	C12—C14	1.442 (4)
C3—C4	1.447 (3)	C13—H13A	0.9300
C3—C15	1.499 (3)	C13—H13B	0.9300
C4—C9	1.381 (3)	C14—H14A	0.9600
C4—C5	1.406 (3)	C14—H14B	0.9600
C5—C6	1.367 (3)	C14—H14C	0.9600
C5—H5	0.9300	C15—H15A	0.9600
C6—C7	1.385 (3)	C15—H15B	0.9600
C6—H6	0.9300	C15—H15C	0.9600

C11—S1—C7	90.94 (11)	O1—C9—C8	116.39 (18)
C9—O1—C1	121.72 (17)	C4—C9—C8	122.13 (19)
O2—C1—O1	116.7 (2)	C11—C10—C8	110.4 (2)
O2—C1—C2	126.1 (2)	C11—C10—C12	121.8 (2)
O1—C1—C2	117.21 (19)	C8—C10—C12	127.7 (2)
C3—C2—C1	122.6 (2)	C10—C11—S1	115.0 (2)
C3—C2—H2	118.7	C10—C11—H11	122.5
C1—C2—H2	118.7	S1—C11—H11	122.5
C2—C3—C4	119.1 (2)	C13—C12—C14	123.5 (3)
C2—C3—C15	121.8 (2)	C13—C12—C10	119.4 (3)
C4—C3—C15	119.1 (2)	C14—C12—C10	117.0 (2)
C9—C4—C5	118.38 (19)	C12—C13—H13A	120.0
C9—C4—C3	117.90 (19)	C12—C13—H13B	120.0
C5—C4—C3	123.7 (2)	H13A—C13—H13B	120.0
C6—C5—C4	121.8 (2)	C12—C14—H14A	109.5
C6—C5—H5	119.1	C12—C14—H14B	109.5
C4—C5—H5	119.1	H14A—C14—H14B	109.5
C5—C6—C7	118.1 (2)	C12—C14—H14C	109.5
C5—C6—H6	120.9	H14A—C14—H14C	109.5
C7—C6—H6	120.9	H14B—C14—H14C	109.5
C6—C7—C8	123.2 (2)	C3—C15—H15A	109.5
C6—C7—S1	125.92 (17)	C3—C15—H15B	109.5
C8—C7—S1	110.87 (16)	H15A—C15—H15B	109.5
C7—C8—C9	116.35 (19)	C3—C15—H15C	109.5
C7—C8—C10	112.72 (19)	H15A—C15—H15C	109.5
C9—C8—C10	130.9 (2)	H15B—C15—H15C	109.5
O1—C9—C4	121.46 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11···O2ⁱ	0.93	2.44	3.293 (3)	153

Symmetry code: (i) −x+1, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₅H₁₂O₂S
M_r	256.31
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	8.547 (2), 11.425 (3), 13.641 (4)
β (°)	108.259 (19)
V (Å³)	1265.0 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.25
Crystal size (mm)	0.50 × 0.15 × 0.12

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.887, 0.971
No. of measured, independent and observed [I > 2σ(I)] reflections	5816, 2698, 1870
R_int	0.091
(sin θ/λ)_max (Å⁻¹)	0.639

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.068, 0.177, 0.99
No. of reflections	2698
No. of parameters	166
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	D—H···A
C11—H11···O2ⁱ	0.93	2.44	3.293 (3)	153

Symmetry code: (i) −x+1, y−1/2, −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

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