Collect. Czech. Chem. Commun. 1986, 51, 2810-2816

2-Isothiocyanatobenzylpyridinium bromide - An intermediate for the synthesis of 2-arylamino-4H-benzo[d][1,3]thiazines

Jozef Gonda and Pavol Kristian

Department of Organic Chemistry and Biochemistry, faculty of Natural Sciences, P. J. Šafárik University, 041 67 Košice


2-Bromomethylphenyl isothiocyanate reacts with pyridine to yield 2-isothiocyanatobenzylpyridinium bromide, which afforded N-aryl-N'-(2-benzylpyridinium)thiourea bromides. Deprotonization of the latter with aqueous NaOH gave N-aryl-N'-(2-benzylpyridinium) thioureates; these freed pyridine upon heating to give 2-arylamino-4H-benzo[d][1,3]thiazines. Structure of these compounds was evidenced by IR, 1H, 13C NMR and mass spectral data and backed by elemental analysis.