Abstract On reacting the cyclic enaminothiones 1 with alkyl halides and pulverized sodiumhydroxide in acetone, the hitherto difficultly accessible thioenimines 8 are obtained in fair yield. They show ZE isomerism at the substituted imino group. The isomers were assigned by 1H-NMR-spectroscopy using anisotropy, long range coupling and ASIS. From the heights of the barriers of isomerization, depending on the p-substituents of some N- ...