(IUCr) (±)-trans-6,7-Dimethoxy-1-oxo-3-(2-thienyl)isochroman-4-carboxylic acid

Volume 65
Part 6
Page o1377
June 2009

Received 11 May 2009
Accepted 18 May 2009
Online 23 May 2009

Key indicators
Single-crystal X-ray study
T = 296 K
Mean (C-C) = 0.002 Å
Disorder in main residue
R = 0.044
wR = 0.113
Data-to-parameter ratio = 14.7
Details

(±)-trans-6,7-Dimethoxy-1-oxo-3-(2-thienyl)isochroman-4-carboxylic acid

Mehmet Akkurt,^a ^* Zeliha Baktir,^a Milen G. Bogdanov,^b Ivan V. Svinyarov ^b and Orhan Büyükgüngör ^c

^aDepartment of Physics, Faculty of Arts and Sciences, Erciyes University, 38039 Kayseri, Turkey,^bFaculty of Chemistry, University of Sofia, 1 James Bourchier Boulevard, 1164 Sofia, Bulgaria, and ^cDepartment of Physics, Faculty of Arts and Sciences, Ondokuz Mayis University, 55139 Samsun, Turkey
Correspondence e-mail: akkurt@erciyes.edu.tr

The title compound, C₁₆H₁₄O₆S, was synthesized by the reaction of 6,7-dimethoxyhomophthalic anhydride with thiophene-2-carbaldehyde in the presence of 4-(dimethylamino)pyridine (DMAP) as a basic catalyst. The thiophene ring of the title molecule is disordered over two sites with occupancies of 0.877 (3) and 0.123 (3). The disorder corresponds to an approximate 180° rotation of the thiophene ring with respect to the C-C bond linking it to the rest of the molecule. The six-membered ring of the 3,4-dihydroisochromanone ring system is not planar [puckering parameters Q_T = 0.571 (2) Å, [theta] = 115.2 (2)° and [varphi] = 99.1 (2)°]. The benzene ring of the 3,4-dihydroisochromanone ring system makes dihedral angles of 75.0 (2) and 77.2 (5)° with the disordered thiophene rings. Intermolecular O-HO and C-HO hydrogen bonds, as well as C-H [pi] interactions, lead to the observed supramolecular structure.

Related literature

For details of the synthesis of the title compound, see: Bogdanov & Palamareva (2004). For the synthesis of new dihydroisocoumarins, see: Bogdanov et al. (2007a,b). For ring-puckering parameters, see: Cremer & Pople (1975).

Experimental

Crystal data

C₁₆H₁₄O₆S
M_r = 334.34
Triclinic, $[P \overline 1]$
a = 8.3369 (6) Å
b = 8.4587 (6) Å
c = 11.9143 (9) Å
= 76.441 (6)°
= 81.127 (6)°
= 72.958 (6)°
V = 777.6 (1) Å³
Z = 2
Mo K radiation
= 0.24 mm^-1
T = 296 K
0.53 × 0.41 × 0.21 mm

Data collection

Stoe IPDS II diffractometer
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) T_min = 0.885, T_max = 0.952
8329 measured reflections
3229 independent reflections
2663 reflections with I > 2(I)
R_int = 0.030

Refinement

R[F² > 2(F²)] = 0.044
wR(F²) = 0.113
S = 1.07
3229 reflections
219 parameters
13 restraints
H atoms treated by a mixture of independent and constrained refinement
_max = 0.27 e Å^-3
_min = -0.31 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O6-H6O3ⁱ	0.86 (3)	1.84 (2)	2.658 (2)	159 (3)
C2-H2O5ⁱⁱ	0.93	2.54	3.465 (2)	172
C10-H10O6ⁱⁱⁱ	0.98	2.54	3.475 (2)	159
C11-H11Cg4^iv	0.98	2.61	3.525 (2)	156
Symmetry codes: (i) x, y+1, z; (ii) -x+1, -y+2, -z+1; (iii) -x, -y+2, -z+1; (iv) -x+1, -y+1, -z+1. Cg4 is the centroid of the C1-C6 ring.

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IM2117 ).

Acknowledgements

The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayis University, Turkey, for the use of the Stoe IPDS2 diffractometer (purchased under grant F.279 of the University Research Fund).

References

Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.
Bogdanov, M. G., Gocheva, B. T., Dimitrova, D. B. & Palamreva, M. D. (2007a). J. Heterocycl. Chem. 44, 673-677.
Bogdanov, M. G., Kandinska, M. I., Dimitrova, D. B., Gocheva, B. T. & Palamareva, M. D. (2007b). Z. Naturforsch. Teil C, 62, 477-482.
Bogdanov, M. G. & Palamareva, M. D. (2004). Tetrahedron, 60, 2525-2530.
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.

organic compounds