Cyclic amidines. Part XXII. 1-Aryl-1,2-dihydro-2-iminopyridines
Abstract
Interaction of ethyl 2-cyano-3-oxobutyrate and an arylamine salt yields a 1-aryl-5-cyano-1,2-dihydro-2-imino-pyridine and an ethyl 3-arylamino-2-cyanocrotonate. The 1-aryl-2-iminopyridines are hydrolysed by water to 1-aryl-2-pyridones and with alkali undergo the Dimroth rearrangement to 2-arylaminopyridines. Ethyl 3-arylamino-2-cyanocrotonates are readily cyclised to 3-cyanoquinolines.