1H NMR long-range coupling in the assignment of stereochemistry to 4-imidazolidinones

Long-range couplings were observed between protons attached to C-2 and C-5 of the 4-imidazolidinone ring. Since ⁴J(25) has a measurable value only for a trans arrangement of H-2 and H-5, this coupling can be utilized as an easy method of identification of 4-imidazolidinone stereoisomers.