Abstract The 13 C NMR spectra of some 1-and 2-substituted perimidines and perimidinium salts are discussed and assigned. Although the spectra of most of the 2-substituted perimidines are comparatively simple, several examples display 13 C and 1 H spectral characteristics indicative of inhibition of prototropic tautomerism.
![10,11-dihydro-9H-[1,3]thiazino[3,2-a]perimidine Structure](https://image.chemsrc.com/caspic/249/72391-43-6.png)
