Crystal structures of two thiazolidinone derivatives bearing a trichloromethyl substituent at the 2-position

The title compounds 2-trichloromethyl-3-phenyl-1,3-thiazolidin-4-one (C10H8Cl3NOS), 1 and 3-(4-chlorophenyl)-2-trichloromethyl-1,3-thiazolidin-4-one (C10H7Cl4NOS) 2, are structurally related with one atom substitution difference in the para position of the benzene ring. In both structures, the thiazolidinone ring adopts an envelope conformation with the S atom as the flap. The dihedral angles between the rings [48.72 (11) in 1 and 48.42 (9)degrees in 2] are very similar and the molecules are almost superimposable. In both crystal structures, C-H center dot center dot center dot O 'head-to-tail' interactions between the chiral carbon atoms and the thiazolidinone oxygen atoms result in infinite monochiral chains along the direction of the shortest unit-cell parameter, namely a in 1 and b in 2. C-H center dot center dot center dot pi interactions between the thiazolidinone carbon atom at the 4-position and the phenyl ring of the neighboring enantiomer also help to stabilize the packing in each case, although the crystals are not isostructural.