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Ceftibuten, C15H14N4O6S2, with the systematic name (6R,7R)-7-{[(Z)-2-(2-amino-1,3-thia­zol-4-yl)-4-carb­oxy­but-2-eno­yl]amino}-8-oxo-5-thia-1-aza­bicyclo­[4.2.0]oct-2-ene-2-carb­oxy­lic acid, is a third generation, orally administered cephalosporin anti­biotic with broad anti­microbial activity and stability against extended spectrum β-lactamases. Ceftibuten can exist in various hydration states and to better understand the location of the water mol­ecules of crystallization and their effect on the structure, the crystal structures of anhydrous (I) and hydrated (II) ceftibuten were determined and both occur as zwitterions with proton transfer from the carboxyl­ate group adjacent to the β-lactam ring to the N atom of the thia­zole ring. The β-lactam ring in (I) is almost planar but the equivalent grouping in (II) is slightly buckled. In the extended structure of (I), O—HO and N—HO hydrogen bonds link the mol­ecules into a three-dimensional network. In (II), O—HOc, N—HOc, O—HOw, N—HOw and Ow—HOw (c = ceftibuten, w = water) hydrogen bonds link the components into a three-dimensional network. A large void space is present within the anhydrous crystal structure that can accommodate between two and three mol­ecules of water. [ABSTRACT FROM AUTHOR]

A unique 11b-substituted indeno[2,1-c|quinolin-6-one ring system was prepared in good yield and the structure of the product was unequivocally determined by X-ray crystallography. [ABSTRACT FROM AUTHOR]