4-Bromo-3-{N-[2-(3,4-dimethoxyphenyl)ethyl]-N-methylsulfamoyl}-5-methylbenzoic acid monohydrate

In the title compound, C19H22BrNO6S·H2O, the dihedral angle between the planes of the two benzene rings is 3.1 (1)°. These rings are stacked over one another with their centroids separated by 3.769 (2) Å, indicating weak π–π interactions. In the crystal structure, molecules are linked by O—H⋯O and O—H⋯(O,O) hydrogen bonds involving the water molecule, forming a two-dimensional network parallel to (001).

In the title compound, C 19 H 22 BrNO 6 SÁH 2 O, the dihedral angle between the planes of the two benzene rings is 3.1 (1) . These rings are stacked over one another with their centroids separated by 3.769 (2) Å , indicating weakinteractions. In the crystal structure, molecules are linked by O-HÁ Á ÁO and O-HÁ Á Á(O,O) hydrogen bonds involving the water molecule, forming a two-dimensional network parallel to (001).

Comment
Sulfonamides are a class of anti-microbial agents that have seen extensive use in medicine. They are the first agents to be used for the treatment of bacterial infection (Cates, 1986). Sulfonamides are used to treat atrophic rhinitis in swine and heart water in cattle and many other diseases in a variety of animals (Steele & Beran, 1984). In adition sulfonamides have a variety of biological activities such as antibacterial, antimalarial and antileprotic agents (Benedetti, 1987;Mengelers et al., 1997).
The geometric parameters of the title molecule agree well with those reported for similar structures (Babu et al., 2009a,b;Shad et al., 2009). In the molecular structure, the two benzene rings are stacked over one another with their centroids separated by 3.769 (2) Å, indicating a weak π-π interaction. The dihedral angle between the two benzene rings is 3.1 (1)°.

Experimental
A solution of 2-(3,4-dimethoxyphenyl)-N-methyl ethanamine (1 g, 0.0051 mol) in ethyl acetate (20 ml) was charged into a round bottom flask equipped with thermometer pocket, condenser and guard tube. Then, pyridine (0.81 g, 0.0102 mol) was added at 25-30°C. After 5 min stirring, 2-bromo-5-(chlorosulfonyl)-3-methylbenzoic acid (0.96 g, 0.00307 mol) was charged into the reaction mass and heated to 45-50°C and maintained for 5-6 h. The completion of the reaction was checked by thin layer chromatography (1:1 hexane-ethyl acetate) and the reaction mass was cooled to 25-30 °C and quenched with 20 ml of water. Then, the aqueous layer was separated and the ethyl acetate layer was washed twice with 10% sodium chloride solution and dried over 2 g of anhydrous sodium sulfate. The solvent was distilled under vacuum at 35-40°C and the crude compound isolated. The crude compound was purified through column chromatography using hexane and ethyl acetate as eluents.

Refinement
Atoms H1W and H2W were located in a difference difference Fourier map and refined freely. Other H atoms were positioned geometrically and refined using a riding model with C-H = 0.93 Å and U iso (H) = 1.2U eq (C) for aromatic, C-H = 0.97 Å and U iso (H) = 1.5U eq (C) for methylene, C-H = 0.96 Å and U iso (H) = 1.5U eq (C) for methyl and O-H = 0.82 Å and U iso (H) = 1.2U eq (O) for water H atoms. The O1W-H1W and O1W-H2W distances were restrained to 0.82 (4) Å and atoms O2 and C7 were subjected to a rigid bond restraint. Fig. 1. The molecular structure of the title compound, with atom labels and 30% probability displacement ellipsoids for non-H atoms. The dashed line denotes a hydrogen bond.