Condensations of acylpyridines with amines. Part I. 2-Acylpyridines and aminoacetal
Abstract
Condensation of pyridine-2-aldehyde or 2-acetylpyridine with aminoacetal in the presence of concentrated mineral acids gave 1,4-dihydro-1,4-di-(2′-pyridylmethylene)pyrazidi-inium salts (II; R = H) and 1,4-dihydro-1,4-di-(methyl-2′-pyridylmethylene) pyrazidi-inium salts (II; P = Me), respectively. Some properties and reactions of these salts are described.