Collect. Czech. Chem. Commun. 1983, 48, 3426-3432

Synthesis of 2-amino-5,7-dimethyl-4-oxopyrido[3,4-e]-1,3-thiazines

Dušan Koščík, Pavol Kristian and Ondrej Forgáč

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


New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.