2-n-Butyl-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

The crystal packing of the title compound, C11H13NO3S, exhibits weak intermolecular C—H⋯O hydrogen bonding, which links molecules related by translation along the b axis into chains, and π–π interactions [centroid–centroid distance of 3.778 (2) Å between benzene rings].

The crystal packing of the title compound, C 11 H 13 NO 3 S, exhibits weak intermolecular C-HÁ Á ÁO hydrogen bonding, which links molecules related by translation along the b axis into chains, andinteractions [centroid-centroid distance of 3.778 (2) Å between benzene rings].

Comment
The title compound, (I), also called THIAZONE, is a new skin penetration enhancer. The tests of penetration enhancing behaviors to berberine, ciclopirox olamino and cypermethrin show that penetration enhancing effect ofTHIAZONE is 2.99 times higher than that of AZONE. THIAZONE is widely applied in pharmaceutic industry, cosmetic and health care industry, agriculture and forest industry, and many others (Xiong, 2004). Herewith we report the crystal structure of (I).
In the crystal, the relatively short distance between the centroids of benzene rings from neighbouring molecules (Table   1) suggests an existence of π···π interactions. The crystal packing exhibits also exhibits weak intermolecular C-H···O hydrogen bonds (Table 2), which link the molecules related by translation along b axis into chains.

Experimental
The title compound has been synthesized following the known procedure (Rice & Pettit, 1954). Saccharin sodium 2.65 g (0.011 mol) was dissolved in 20 ml of dried DMF. To the solution,1-butyl bromide 1.37 g (0.01 mol) was added. The mixture was stirred for half an hour at room temperature and then the mixture was heated with strring for 2 h at 100° C. The mixture was poured into water, and 2.50 g of the product were obtained (yield 95.7%). Single crystals suitable for X-ray measurement were obtained by recrystallization from dichloromethane at room temperature.

Refinement
All H atoms were placed in idealized positions and constrained to ride on their parent atoms,with C-H distances of 0.95 (aromatic), 0.98 (CH 3 ) and 0.99 Å (CH 2 ),and with U iso (H) values set at 1.5 U eq (C)(for CH 3 ) or 1.2 U eq (C)(for CH 2 , aromatic CH). Fig. 1. The molecular structure of (I) showing the atomic numbering and displacement ellipsoids drawn at the 40% probability level.