Lessons of 3‐Alkoxy‐4‐(p‐chlorophenyl)‐1,3‐thiazole‐2(3H)‐thione Chemistry Learned from Structural Investigations

Synthetic, spectroscopic, and structural investigations provided evidence that distinguished neat 3‐alkoxy‐4‐(p‐chlorophenyl)‐1,3‐thiazole‐2(3H)‐thiones (CPTTORs), once developed to serve as alkoxyl radical precursors for storage and use on demand, showed background reactivity. Selectivity in these transformations was guided by the nature of the O‐alkyl substituent. Two pathways reflected the inherent weakness of the N,O bond, leading to products of isomerization and rearrangement. In a third instance, methyl translocation from oxygen to sulfur occurred to furnish a heteroaromatic N‐oxide at the expense of a cross conjugated π‐system. Consistent X‐ray crystallographic data sets served as a basis for electronic structure method assessment in order to model aspects relevant to structure and decomposition chemistry that were not available from diffraction data.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) Distinguished neat 3‐alkoxy‐4‐(p‐chlorophenyl)‐1,3‐thiazole‐2(3H)‐thiones showed unexpected background reactivity via (i)isomerization (ii) rearrangement, or (iii) fragmentation. Selectivity was guided by the nature of the 3‐alkoxy substituent.