Ir and pmr spectra of 2‐aryl‐4‐thiazolidinones. III. Stereochemical analysis of 2‐aryl‐3‐(2‐pyridyl)‐4‐thiazolidinones

Abstract

The long‐range coupling through the sulphur atom observed in a number of 2‐aryl‐3‐(2‐pyridyl)‐4‐thiazolidinones suggests that the C2 proton and one of methylene protons are in a cis 1,3 diequatorial relationship. Some additional information concerning the preferred orientations of the substituents in this system are given from Eu(fod)3, [tris(1,1,1,2,2,3,3‐heptafluoro‐7,7‐dimethyloctane‐4,6‐dionato)]europium, induced shift data.

Structure of 3-(2-pyridyl)-2-(2-tolyl)-1,3-thiazolidin-4-one, C15H14N2OS

“…In an earlier study (Vigorita, Chimirri, Grasso & Fenech, 1979) the IR and IH NMR spectra were consistent with the presence of one conformer in solution. In fact, the carbonyl band became single and IH NMR signals did not show any multiplicity.…”

“…For this reason, investigations were undertaken (Vigorita, Chimirri, Grasso & Fenech, 1979) to determine its preferred conformations in solution from IR and ~H NMR studies; the IR solid-phase analysis was temporarily set aside since the carbonyl absorption showed a strange splitting into two bands. This suggested the possibility of other conformations which are not present in the liquid phase.…”

Synthesis and antihistaminic activity of some thiazolidin-4-ones

“…2-(4-Aminophenyl)-3-[3-(JV,JV-dimethylamino)propyl]l,3-thiazolidin-4-one (8). 2-(4-Nitrophenyl)-3-[3-(lVJV-dimethylamino)propyl]-l,3-thiazolidin-4-one (7) (0.005 mol) was dissolved in an ethanol-water mixture (50 mL, 3:2, v/v).…”

2-Amino-5,5-dimethylthiazol-4(5H)-one

“…The title compound provides an avenue for a new substitution pattern that is not often seen in the literature, namely, a geminal dialkyl substitution at the 5-position on the ring. This motif may provide a unique utility since a more thermodynamically favored confirmation may result because of steric hindrance, especially if the thiazolidinone is further substituted at the 2-and/or N-positions (Vigorita et al 1979).…”