SYNTHESIS, STRUCTURE, TAUTOMERISM, AND 1,4-DIPOLAR CYCLOADDITION OF THERMALLY STABLE, CRYSTALLINE 1,4-DIPOLES

Phenyl isothiocyanate reacted with 2-methylene-1,3-dimethylimidazolidi nes to give thermally stable, crystalline adducts that possess an inne r salt (1,4-dipolar) structure or its tautomeric thioamide structure d epending on substituent on the methylene part. Tautomerism between the 1,4-dipolar form and the thioamide form, X-ray diffraction analysis, and 1,4-dipolar cycloaddition with DMAD of these adducts are reported.