An Experimental and Theoretical Conformational Study of a Series of Substituted 3-cyclohexyl-2-phenyl-1,3-thiazolidin-4-ones

Abstract

A series of novel 3-cyclohexyl-2-phenyl-1,3-thiazolidin-4-one derivatives with substituents on the 2-phenyl ring were synthesized, and a study of their solid state and solution conformations was effected. In solution the thiazolidin-4-one ring preferred the C2 phenyl in a pseudo-equatorial orientation and the solid state indicated a preference for the C2 phenyl being in a pseudo-axial orientation. Less robust substituent chemical shift (SCS) correlations utilizing 13C NMR were observed in this instance than in prior studies. Molecular modeling studies using Moller-Plessett second-order perturbation theory (MP2) indicate that the thiazolidinone ring and cyclohexyl ring conformations exhibit a global minimum consistent with the solution studies.