NMR spectral parameters of 1-chloroaziridine

l-Chloroaziridine is a classical case of hindered nitrogen inversion. Doubt has been cast on the PMR data obtained for this compound (3Jtran s = 2.54, 2j = -1.72 Hz) [i] since these coupling constants are significantly less than for l-chloro-2-methylaziridine [2] and other aziridines [3]. We obtained the following parameters by analyzing the PMR spectra at 400 MHz in CDCI 3 using the PANIC iteration program. These parameters differ significantly from those obtained by Pauelsen and Greve [i].