Synthesis of hetaryl pyridinium salts and fused 3-amino-pyrid-2-ones

1-(3-Coumaryl)-pyridinium salts 3 and 1-(3-coumaryl)-tetrahydrothiophenium salts 5 were synthesized from 2-acylphenyl chloro- or bromoacetates 2. 2-Ch loro-N-1-(3,4-dimethoxyphenyl)-acetamide and substituted 2-chloro-N-1-(2-th ienyl)-acetamides 8 react with acetyl chloride and pyridine to yield the qu inolinyl- and (thieno[2,3-b]pyridin-5-yl)-pyridinium salts 10. Fused thieno [2,3-b]pyridin-ones 19 were formed from N-chloroacetyl-2-aminothiophen-3 -c arbonitriles 16 with pyridine via Thorpe-Ziegler cyclization and followed b y cyclodehydrogenation. In presence of pyridine alkyl 2-chloro-acetylaminob enzoates 21 yield 3-(1 -pyridinio)-quinoline-4-olates 23. Zincke-cleavage o f 10 and 23 with hydrazinium hydroxide leads to fused 3-amino-pyridine-2-on es 11 and 3-amino-4-hydroxy-quinoline-2-ones 24, respectively. Oxazoloquino lines 25 were synthesized from 24 with acetic anhydride.