Structure of an Anomalous Heterocyclic Intermediate

IN the preparation of the disulphide of 2-(2-mercapto-ethylamino)-2-oxazoline from 2-methylthio-2-oxazoline and 2-mercaptoethylamine hydrochloride, an intermediate with anomalous properties was encountered 1 . The properties of the intermediate, C 5 H 10 N 2 OS, were not consistent with its formulation as the ancitipated 2-(2-mercapto-ethylamino)-2-oxazoline (I), and spectroscopic evidence (infra-red and nuclear magnetic resonance spectra) suggested the possibility that the novel heterocyclic spiran (II) had been obtained. In order to establish the structure of this anomalous intermediate unambiguously, we undertook an X-ray crystal-structure analysis.