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Acta Cryst. (2008). E64, o1669    [ doi:10.1107/S1600536808021260 ]

1-[(4,5-Dimethylcyclohexa-1,4-dien-1-yl)sulfonyl]-4-methylbenzene

R. H. Gray, F. R. Fronczek and M. G. H. Vicente

Abstract top

In the title molecule, C15H18O2S, the dimethylcyclohexadiene unit is slightly non-planar, having a folded conformation with the two double-bond planes forming a dihedral angle of 3.9 (6)°. Methyl groups of the dimethylcyclohexadiene ring tilt away from each other, forming internal C-C-C(Me) angles approximately 11° greater than the exterior angles.

Comment top

The title compound, synonym 3,4-dimethyl-tosyl-cyclohexadiene, (I) is an important intermediate in the synthesis of 3,4-disubstituted pyrroles and isoindoles (Filatov et al., 2007). In particular, the 4,7-dihydroisoindole obtained in one step from (I) has been used in the total syntheses of tetrabenzoporphyrins (TBP) and tetrabenzocorroles (TBC) for application in cancer therapy by photodynamic therapy (PDT), and in the syntheses of BODIPY-type molecules for cancer imaging and diagnosis. On account of their strong absorptions and fluorescence emissions in the near IR region of the spectrum and their high chemical stability, these compounds have shown promise for the above biomedical applications (Ongayi, 2005; Loudet & Burgess, 2007). Compound (I) was prepared by a Diels-Alder cycloaddition reaction of 2,3-dimethylbutadiene with tosyl-acetylene at 60–70 °C.

Compound (I) contains a sulfonyl center which offsets both the tolyl and the dimethylcyclohexadienyl groups from linearity, with C1—S1—C9 angle 102.96 (6)°. Similarly, a 104.20 (5)° C—S—N angle is found in a related tosyl-pyrrole (Tanui et al., 2008).

The cyclohexadiene ring in (I) is nearly planar, exhibiting a slight fold along the C2···C5 line, which joins the two C—C==C—C planes. Those planes form a dihedral angle of 3.9 (6)°. The cyclohexadiene ring forms a dihedral angle of 85.70 (3)° with the phenyl ring plane. The two methyl groups on adjacent C atoms of the cyclohexadiene ring are bent away from each other, causing the interior C—C—C(Me) angles to be approximately 11° greater than exterior angles. The interior angles are 124.36 (15)° at C3 and 123.76 (15)° at C4, while the exterior angles are 112.90 (14)° at C3 and 113.97 (14)°. The methyl groups also twist out of plane, forming a C7—C3—C4—C8 torsion angle of 2.1 (2)°. These methyl groups have an intramolecular H···H contact 2.08 Å (based on H positions determined with HFIX 137), about 0.3 Å less than their van der Waals radii sum.

The structure of a related tosylate compounds have been reported, i.e. 3,4-dimethylbenzenesulfonyl chloride (Glidewell et al., 2001) and 3,4,4-trimethyldiphenyl sulfone (Ogura et al., 2001). The first, QIBREY, differs in 2 ways: a 3,4-dimethylphenyl rather than a 3,4-dimethylcyclohexadiene and a p-Cl phenyl rather than tolyl on the SO2 center. QIBREY has very similar cell dimensions (in its P21/n setting) to (I), and also similar packing, but the two structures are not isomorphous.

Related literature top

For related literature, see: Filatov et al. (2007); Glidewell et al. (2001); Loudet & Burgess (2007); Ogura et al. (2001); Tanui et al. (2008); Ongayi (2005); Pomarico (2009).

Experimental top

The synthesis of the compound was adapted from Pomarico (2009): To a 50 ml round bottom flask, tosyl-acetylene (MW 180, 1.3305 g, 7.39 mmol) and 832 υl of 2,3-dimethylbutadiene (MW 82.15, d 0.726 g/ml) were dissolved in 25 ml of anhydrous toluene. N2 was introduced for an inert atmosphere. Reaction tube was stirred at 60–70° C for 72 h. Residue was purified by a silica gel column and eluted with hexane-ethyl acetate (4:1). (I) was obtained in the first band. The desired fractions were covered with Parafilm and punctured to allow solvent evaporation. After 72 h, the most concentrated fraction(s) was driven to super-saturation and formed needle crystals (compound I) in solution. The other fractions yielded a yellow-white solid powder (compound I, impure). Yield: 71% (1.3864 g, 5.27 mmol). Spectroscopic analysis, 1H NMR (400 MHz, CDCl3, 299 K): 7.78 (2H, d, CH), 7.37 (2H, d, CH), 6.93 (1H, s, CH), 2.80 (2H, s, CH2), 2.65 (2H, d, CH2), 2.39 (3H, s, CH3), 1.57 (6H, s, CH3). MS (EI) m/z: 263.1098 (M+).

Refinement top

H atoms on C were placed in idealized positions with C—H distances 0.95 - 0.99 Å and thereafter treated as riding. Uiso for H was assigned as 1.2 times Ueq of the attached atoms (1.5 for methyl).

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006); data reduction: APEX2 (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Ellipsoids at the 50% level, with H atoms having arbitrary radius.
[Figure 2] Fig. 2. The packing viewed approximately down the symmetry direction. H atoms are not shown.
1-[(4,5-Dimethylcyclohexa-1,4-dien-1-yl)sulfonyl]-4-methylbenzene top
Crystal data top
C15H18O2SF000 = 560
Mr = 262.35Dx = 1.307 Mg m−3
Monoclinic, P21/cCu Kα radiation
λ = 1.54178 Å
Hall symbol: -P 2ybcCell parameters from 6824 reflections
a = 14.1607 (10) Åθ = 3.1–69.6º
b = 7.5766 (5) ŵ = 2.08 mm−1
c = 12.6923 (10) ÅT = 90 K
β = 101.658 (5)ºNeedle fragment, colourless
V = 1333.66 (17) Å30.37 × 0.29 × 0.21 mm
Z = 4
Data collection top
Bruker Kappa APEXII CCD area-detector
diffractometer		2414 independent reflections
Radiation source: fine-focus sealed tube2388 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.017
T = 90 Kθmax = 70.0º
φ and ω scansθmin = 6.3º
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008)		h = −16→17
Tmin = 0.513, Tmax = 0.669k = −8→8
8185 measured reflectionsl = −14→15
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.031  w = 1/[σ2(Fo2) + (0.0349P)2 + 1.1601P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.079(Δ/σ)max = 0.001
S = 1.02Δρmax = 0.39 e Å−3
2414 reflectionsΔρmin = −0.35 e Å−3
167 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0014 (2)
Secondary atom site location: difference Fourier map
Crystal data top
C15H18O2SV = 1333.66 (17) Å3
Mr = 262.35Z = 4
Monoclinic, P21/cCu Kα
a = 14.1607 (10) ŵ = 2.08 mm−1
b = 7.5766 (5) ÅT = 90 K
c = 12.6923 (10) Å0.37 × 0.29 × 0.21 mm
β = 101.658 (5)º
Data collection top
Bruker Kappa APEXII CCD area-detector
diffractometer		2414 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008)		2388 reflections with I > 2σ(I)
Tmin = 0.513, Tmax = 0.669Rint = 0.017
8185 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.031167 parameters
wR(F2) = 0.079H-atom parameters constrained
S = 1.02Δρmax = 0.39 e Å−3
2414 reflectionsΔρmin = −0.35 e Å−3
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
S10.72081 (2)0.65111 (5)0.77242 (3)0.01466 (12)
O10.77069 (8)0.81816 (14)0.78620 (9)0.0217 (3)
O20.69509 (8)0.57537 (14)0.66619 (8)0.0203 (2)
C10.78977 (10)0.4965 (2)0.85979 (11)0.0150 (3)
C20.84519 (10)0.5644 (2)0.96471 (12)0.0181 (3)
H2A0.80130.63421.00010.022*
H2B0.89640.64470.95070.022*
C30.89062 (10)0.4216 (2)1.04018 (12)0.0192 (3)
C40.88460 (10)0.2504 (2)1.01358 (12)0.0199 (3)
C50.83462 (11)0.1878 (2)0.90446 (12)0.0213 (3)
H5A0.88270.12940.86950.026*
H5B0.78630.09780.91370.026*
C60.78555 (10)0.3272 (2)0.83147 (12)0.0172 (3)
H60.75010.29460.76250.021*
C70.93992 (11)0.4914 (2)1.14845 (12)0.0258 (4)
H7A0.89160.54021.18570.039*
H7B0.98560.58411.13880.039*
H7C0.97460.39511.19130.039*
C80.92390 (13)0.1033 (3)1.09036 (14)0.0301 (4)
H8A0.98550.14011.13520.045*
H8B0.9339−0.00231.04940.045*
H8C0.87790.07681.13640.045*
C90.61462 (10)0.67078 (18)0.82478 (11)0.0138 (3)
C100.53295 (10)0.57652 (19)0.77775 (12)0.0171 (3)
H100.53260.50720.71530.021*
C110.45159 (10)0.58476 (19)0.82322 (12)0.0185 (3)
H110.39500.52290.79030.022*
C120.45178 (11)0.6823 (2)0.91624 (12)0.0178 (3)
C130.53499 (11)0.7747 (2)0.96241 (11)0.0177 (3)
H130.53610.84101.02620.021*
C140.61613 (10)0.77178 (19)0.91700 (11)0.0157 (3)
H140.67190.83750.94820.019*
C150.36432 (12)0.6882 (2)0.96662 (13)0.0248 (4)
H15A0.33240.80290.95190.037*
H15B0.38410.67161.04450.037*
H15C0.31960.59400.93630.037*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.01540 (19)0.0156 (2)0.01337 (19)0.00057 (13)0.00388 (13)0.00124 (13)
O10.0225 (6)0.0181 (5)0.0260 (6)−0.0034 (4)0.0087 (4)0.0027 (4)
O20.0232 (5)0.0250 (6)0.0128 (5)0.0045 (4)0.0039 (4)0.0005 (4)
C10.0121 (6)0.0188 (7)0.0144 (7)0.0010 (6)0.0034 (5)0.0008 (6)
C20.0149 (7)0.0216 (8)0.0172 (7)0.0000 (6)0.0018 (6)−0.0032 (6)
C30.0123 (7)0.0312 (9)0.0144 (7)0.0017 (6)0.0037 (5)−0.0014 (6)
C40.0153 (7)0.0277 (9)0.0175 (7)0.0048 (6)0.0055 (6)0.0029 (6)
C50.0217 (8)0.0199 (8)0.0226 (8)0.0034 (6)0.0050 (6)0.0005 (6)
C60.0152 (7)0.0207 (8)0.0155 (7)−0.0004 (6)0.0030 (6)−0.0018 (6)
C70.0205 (8)0.0399 (10)0.0161 (7)0.0047 (7)0.0013 (6)−0.0043 (7)
C80.0313 (9)0.0366 (10)0.0236 (8)0.0125 (8)0.0086 (7)0.0093 (7)
C90.0147 (7)0.0127 (7)0.0141 (7)0.0020 (5)0.0033 (5)0.0029 (5)
C100.0196 (7)0.0139 (7)0.0168 (7)0.0017 (6)0.0015 (6)−0.0002 (6)
C110.0156 (7)0.0143 (7)0.0244 (8)−0.0011 (5)0.0012 (6)0.0026 (6)
C120.0189 (7)0.0151 (7)0.0199 (7)0.0051 (6)0.0055 (6)0.0084 (6)
C130.0219 (7)0.0169 (7)0.0141 (7)0.0050 (6)0.0031 (6)0.0013 (6)
C140.0166 (7)0.0140 (7)0.0154 (7)0.0014 (5)0.0002 (5)0.0007 (6)
C150.0224 (8)0.0252 (8)0.0292 (9)0.0051 (6)0.0110 (7)0.0089 (7)
Geometric parameters (Å, °) top
S1—O11.4427 (11)C7—H7C0.9800
S1—O21.4427 (11)C8—H8A0.9800
S1—C11.7656 (14)C8—H8B0.9800
S1—C91.7687 (14)C8—H8C0.9800
C1—C61.331 (2)C9—C101.387 (2)
C1—C21.4939 (19)C9—C141.395 (2)
C2—C31.501 (2)C10—C111.390 (2)
C2—H2A0.9900C10—H100.9500
C2—H2B0.9900C11—C121.392 (2)
C3—C41.339 (2)C11—H110.9500
C3—C71.506 (2)C12—C131.394 (2)
C4—C51.499 (2)C12—C151.505 (2)
C4—C81.511 (2)C13—C141.386 (2)
C5—C61.482 (2)C13—H130.9500
C5—H5A0.9900C14—H140.9500
C5—H5B0.9900C15—H15A0.9800
C6—H60.9500C15—H15B0.9800
C7—H7A0.9800C15—H15C0.9800
C7—H7B0.9800
O1—S1—O2119.15 (7)C3—C7—H7C109.5
O1—S1—C1108.10 (7)H7A—C7—H7C109.5
O2—S1—C1109.04 (7)H7B—C7—H7C109.5
O1—S1—C9108.25 (7)C4—C8—H8A109.5
O2—S1—C9108.14 (7)C4—C8—H8B109.5
C1—S1—C9102.96 (6)H8A—C8—H8B109.5
C6—C1—C2124.03 (13)C4—C8—H8C109.5
C6—C1—S1118.76 (11)H8A—C8—H8C109.5
C2—C1—S1117.11 (11)H8B—C8—H8C109.5
C1—C2—C3113.62 (13)C10—C9—C14120.90 (13)
C1—C2—H2A108.8C10—C9—S1119.54 (11)
C3—C2—H2A108.8C14—C9—S1119.43 (11)
C1—C2—H2B108.8C9—C10—C11119.14 (13)
C3—C2—H2B108.8C9—C10—H10120.4
H2A—C2—H2B107.7C11—C10—H10120.4
C4—C3—C2122.71 (13)C10—C11—C12121.07 (14)
C4—C3—C7124.36 (15)C10—C11—H11119.5
C2—C3—C7112.90 (14)C12—C11—H11119.5
C3—C4—C5122.24 (14)C11—C12—C13118.66 (14)
C3—C4—C8123.76 (15)C11—C12—C15121.03 (14)
C5—C4—C8113.97 (14)C13—C12—C15120.31 (14)
C6—C5—C4115.24 (13)C14—C13—C12121.22 (14)
C6—C5—H5A108.5C14—C13—H13119.4
C4—C5—H5A108.5C12—C13—H13119.4
C6—C5—H5B108.5C13—C14—C9118.98 (13)
C4—C5—H5B108.5C13—C14—H14120.5
H5A—C5—H5B107.5C9—C14—H14120.5
C1—C6—C5121.90 (14)C12—C15—H15A109.5
C1—C6—H6119.0C12—C15—H15B109.5
C5—C6—H6119.0H15A—C15—H15B109.5
C3—C7—H7A109.5C12—C15—H15C109.5
C3—C7—H7B109.5H15A—C15—H15C109.5
H7A—C7—H7B109.5H15B—C15—H15C109.5
O1—S1—C1—C6−150.24 (12)C4—C5—C6—C13.0 (2)
O2—S1—C1—C6−19.33 (14)O1—S1—C9—C10147.20 (11)
C9—S1—C1—C695.35 (13)O2—S1—C9—C1016.82 (13)
O1—S1—C1—C233.22 (12)C1—S1—C9—C10−98.50 (12)
O2—S1—C1—C2164.13 (10)O1—S1—C9—C14−36.97 (13)
C9—S1—C1—C2−81.20 (12)O2—S1—C9—C14−167.34 (11)
C6—C1—C2—C3−4.3 (2)C1—S1—C9—C1477.34 (12)
S1—C1—C2—C3172.03 (10)C14—C9—C10—C110.5 (2)
C1—C2—C3—C42.4 (2)S1—C9—C10—C11176.30 (11)
C1—C2—C3—C7−175.74 (12)C9—C10—C11—C12−1.6 (2)
C2—C3—C4—C52.1 (2)C10—C11—C12—C131.1 (2)
C7—C3—C4—C5−179.99 (14)C10—C11—C12—C15−178.78 (13)
C2—C3—C4—C8−175.78 (14)C11—C12—C13—C140.5 (2)
C7—C3—C4—C82.1 (2)C15—C12—C13—C14−179.66 (13)
C3—C4—C5—C6−4.9 (2)C12—C13—C14—C9−1.5 (2)
C8—C4—C5—C6173.25 (13)C10—C9—C14—C131.0 (2)
C2—C1—C6—C51.6 (2)S1—C9—C14—C13−174.79 (11)
S1—C1—C6—C5−174.69 (11)
references
References top

Bruker (2006). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.

Filatov, M. A., Cheprakov, A. V. & Beletskaya, I. P. (2007). Eur. J. Org. Chem. pp. 3468–3475.

Glidewell, C., Harrison, W. T. A., Low, J. N., Sime, J. G. & Wardell, J. L. (2001). Acta Cryst. B57, 190–200.

Loudet, A. & Burgess, K. (2007). Chem. Rev. 107, 4891–4932.

Ogura, K., Takeda, M., Xie, J. R., Akazome, M. & Matsumoto, S. (2001). Tetrahedron Lett. 42, 1923–1925.

Ongayi, C. O. (2005). PhD thesis, Louisiana State University, Baton Rouge, USA.

Pomarico, G. (2009). PhD thesis, University of Rome "Tor Vergata", Rome, Italy.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Tanui, H. K., Fronczek, F. R. & Vicente, M. G. H. (2008). Acta Cryst. E64, o130.