3,3′-di[1,3-thiazolidin-4-one] system. Structural and conformational studies on configurational isomers with anti-inflammatory activity

Abstract

3,3′(1,2-Ethanediyl)bis(2-halophenyl-thiazolidin-4-one) derivatives display different pharmacological activities depending on the configuration of the 2,2′ centers and on the oxidation state of the sulfur atoms. Quantum-chemical calculations on the 3-fluorophenyl-substituted configurational isomers are reported here, together with the X-ray structure of the 1∶1 dioxide derivative. This crystallizes in the monoclinic space group P2₁/c, with four molecules per unit cell and cell dimensions:a=18.917(3),b=9.003(2),c=12.062(2)Å, β=96.20(3)°. The compound, which has an approximate center of symmetry in the middle of the ethylene chain and two asymmetric carbon atoms of opposite chiralities, is the (2R,2′S-meso) (or 2S,2′R-meso) stereoisomer.