2-Methoxy-4-methylphenyl 4-toluenesulfonate

In the title molecule, C15H16O4S, the interplanar angle between the two aromatic rings is 45.07 (7)°. The crystal packing is stabilized by weak intermolecular C—H⋯O interactions.

In the title molecule, C 15 H 16 O 4 S, the interplanar angle between the two aromatic rings is 45.07 (7) . The crystal packing is stabilized by weak intermolecular C-HÁ Á ÁO interactions.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT2764).

Comment
Several compounds containing the para-toluene sulfonate moiety are used in the fields of biology and industry. The merging of lipids can be monitored using a derivative of para-toluene sulfonate (Yachi et al., 1989). This method has been used in studying the membrane fusion during the acrosome reaction (Spungin et al., 1984).
The geometric parameters in the title compound agree with the reported values of similar structures (Manivannan et al., 2005a,b;Ramachandran et al., 2007). The aromatic rings make a dihedral angle of 45.07 (7)° with respect to each other.
The crystal packing is stabilized by weak intermolecular C-H···O interactions.
The angle between the two oxygen atoms of the -SO2-group is much larger than the tetrahedral angle which leads to the decrease in the -O-S-Ar angle.

Experimental
A solution of vanillin in toluene was treated with amalgamated Zinc wool and concentrated HCl under reflux for thirty hours. The reaction mixture was cooled. The organic layer was separated and the aqueous layer was washed with ether.
The combined ether and toluene solutions were washed with water, dried over anhydrous calcium chloride and the solvent removed under reduced pressure to get 2-methoxy-4-methyl phenol. A mixture of the above phenol and triethyl amine in acetone was treated with p-toluene sulfonyl chloride at room temperature for twelve hours. The residue was washed with triethyl amine solution and water and dried. Diffraction quality crystals were obtained from the solid by recrystallizing from ethanol.

Refinement
H atoms were positioned geometrically and refined using riding model with C-H = 0.93 Å and U iso (H) = 1.2Ueq(C) for aromatic C-H, C-H = 0.96 Å and U iso (H) = 1.5Ueq(C) for CH 3 . The methyl groups were allowed to rotate but not to tip. Fig. 1. The molecular structure of the title compound with atom labels and 50% probability displacement ellipsoids for non-H atoms. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.