SYNTHESIS OF NEW SUBSTITUTED L-(3-PYRIDYL)PYRIDINIUM SALTS AND 3,4-DIAMINO-2(1H)-PYRIDINONES

2-[(Chloroacetyl)amino]acrylonitriles 1 and 3-[(chloroacetyl)-amino]pr opionitriles 4 were allowed to react with pyridine to form the 1-(4-am ino-3-pyridyl)pyridinium salts 3 and 1-(4-amino-5,6-dihydro-3-pyridyl) pyridinium salts 6. Dehydrogenation of 6 with bromine in glacial aceti c acid afforded 1-(4-amino-3-pyridyl)pyridinium bromides 7. Treatment of 3 and 7 with hydrazine hydrate yielded the 3,4-diamino-2(1H)-pyridi nones 8. Analogously to other ortho diamines, the substituted [1,2,5]t hiadiazolo[3,4-c]pyridin-4-one 10, [1,2,5]selenadiazolo[3,4-c]pyridin- 4-one 11, and further derivatives were obtained from 8. N-(Chloroacety l) derivatives of acetylacetoneimide 13 and 3-oxo-3-phenyl-2-(phenylhy drazono)propionamide 17 were treated with pyridine to give 1-(3-pyridy l)-pyridinium salts 14 and 18 respectively.