N-(4-Acetylphenyl)-4-methoxybenzenesulfonamide

The title compound, C15H15NO4S, was obtained by the condensation of 4-aminoacetophenone and 4-methoxybenzenesulfonyl chloride. The dihedral angle between the benzene rings is 86.56 (9)° and the molecule has an approximate V-shaped conformation. The C atom of the methoxy group is roughly coplanar with its attached ring [deviation = 0.177 (3) Å], as is the methyl C atom of the acetyl group with its ring [deviation = 0.065 (2) Å]. An intramolecular C—H⋯O interaction generates an S(6) ring. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds link the molecules into [010] chains. Weak C—H⋯π interactions are also observed.

The title compound, C 15 H 15 NO 4 S, was obtained by the condensation of 4-aminoacetophenone and 4-methoxybenzenesulfonyl chloride. The dihedral angle between the benzene rings is 86.56 (9) and the molecule has an approximate V-shaped conformation. The C atom of the methoxy group is roughly coplanar with its attached ring [deviation = 0.177 (3) Å ], as is the methyl C atom of the acetyl group with its ring [deviation = 0.065 (2) Å ]. An intramolecular C-HÁ Á ÁO interaction generates an S(6) ring. In the crystal, N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds link the molecules into [010] chains. Weak C-HÁ Á Á interactions are also observed.

Experimental
The title compound was synthesized by condensation of 4-aminoacetophenone (0.40 g, 3 mmol) and 4-methoxybenzenesulfonyl chloride in CH 2 Cl 2 (30 ml) in the presence of pyridine. The reaction mixture was refluxed for 24 hr at 40 °C and monitored with TLC for the completion of the reaction. Water was then added and the concoction was extracted with CH 2 Cl 2 . The solvent was evaporated under reduced pressure to yield the resulting solid of the title compound (yield 68%). Yellow blocks of (I) were recrystalized from acetone:CH 3 OH solution (1:1 v/v) by slow evaporation of the solvent at room temperature after several days, Mp. 448-449 K.

Refinement
Amide H atoms was located from the difference maps and refined isotropically. The remaining H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(C-H) = 0.93 Å for aromatic and 0.96 for CH 3 atoms.
The U iso values were constrained to be 1.5U eq of the carrier atom for methyl H atoms and 1.2U eq for the remaining H atoms. A rotating group model was used for the methyl groups.

Figure 1
The molecular structure of (I), showing 40% probability displacement ellipsoids. The intramolecular C-H···O hydrogen bond is shown as a dashed line.

Figure 2
The V-shape conformation of the molecule.  The crystal packing of the title compound viewed along the c axis. Hydrogen bonds were shown as dashed lines. 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 R-factors(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.