5-Benzyloxy-3-methyl-1-tosyl-1H-indole

The title compound, C23H21NO3S, represents one of the few examples of a 5-substituted indole with a toluenesulfonyl group bonded to the N atom. The benzyl group adopts a synclinal geometry with respect to the indole ring [dihedral angle = 59.95 (4)°], while the tolyl ring is oriented close to perpendicular to the indole ring, making a dihedral angle of 81.85 (3)°. The indole N atom exhibits a slight pyramidalization.

The title compound, C 23 H 21 NO 3 S, represents one of the few examples of a 5-substituted indole with a toluenesulfonyl group bonded to the N atom. The benzyl group adopts a synclinal geometry with respect to the indole ring [dihedral angle = 59.95 (4) ], while the tolyl ring is oriented close to perpendicular to the indole ring, making a dihedral angle of 81.85 (3) . The indole N atom exhibits a slight pyramidalization.

Experimental
To a stirred solution of dimsylsodium [prepared from 110 mg (2.75 mmol) of NaH 60% dispersion in mineral oil and dimethylsulfoxide dry (0.58 ml) at 338 to 343 K until H 2 is no longer evolved] was added a solution of 5-benzyloxy-3methylindole (325 mg, 1.37 mmol) in dry THF (0.9 ml) under ice cooling. After stirring at room temperature for 1 h a solution of 4-methylbenzenesulfonyl chloride (225 mg, 1.18 mmol) in THF (0.9 ml) was added to this mixture at 273 K.
After being stirred at room temperature for 16 h, the reaction product was poured into water and extracted with ethyl acetate. The extract was washed with water, dried over Na 2 SO 4 , and evaporated. The remaining residue was recrystallized from ethyl acetate/hexanes to give 482 mg of the desired product as white needle crystals (90%): mp 402 to 403 K. A suitably sized, block-like crystal was cut from a larger, columnar crystal for the diffraction study.

Refinement
Hydrogen atoms were included in geometrically calculated positions. C-H distances were constrained to 0.95 Å for aromatic and 0.98 -0.99 Å for aliphatic hydrogen atoms. Methyl hydrogen atoms were refined with thermal parameters restrained to U iso H = 1.5 × U eq C and all other hydrogen atoms = 1.2 × U eq C of the carbon to which they are bonded.

Figure 1
Labelling scheme for the title compound. Displacement ellipsoids depicted at 50% probability level. The labeling scheme follows the convention for indoles.