Synthesis of zwitterionic salts via three-component reactions of pyridacylpyridinum iodide, aromatic aldehydes, and Meldrum acid or N,N-dimethylbarbituric acid

New zwitterionic salts of pyridinium–Meldrum acid and pyridinium–barbituric acid are conveniently synthesized from the three-component reactions of 2-, 3-, or 4-pyridacylpyridinum iodides, aromatic aldehydes, and Meldrum acid or N,N-dimethylbarbituric acid in the presence of triethylamine as base promoter in acetonitrile.