Synthesis, properties and structure of 1-acetyl-6-(4-chlorobenzylidene)-2,3,5,6-tetrahydroimidazo[2,1-b]imida zole-3,5-dione

Article abstract of DOI:10.1002/ardp.19953280205

Cyclization of N-[5-(4-chlorobenzylidene)-4-oxo-2-imidazolidinyl]glycine (4) in acetic acid anhydride yielded 1-acetyl-6-(4-chlorobenzylidene)2,3,5,6-tetrahydroimidazo[2,1-b]imidaz ole-3,5-dione (5). The structure of 5 was ascribed on basis of its MS, ¹H- and ¹³C-NMR properties. The crystal structure of 5 was solved by X-ray analysis. On the basis of semiempirical quantum chemistry calculations (PM3 method) the thermodynamic stability of theoretically possible cyclization products was determined. These data allow to predict the direction of cyclization. The stability and the reactivity of 5 toward nucleophilic attack were examined.