One-Step Conversion of 2‑Amino‑<i>N</i>′‑arylbenzamidines into 3‑Aryl-4-imino-3,4-dihydroquinazoline-2-carbonitriles Using 4,5-Dichloro-1,2,3-dithiazolium Chloride
2015-12-16T23:40:24Z (GMT) by
2-Amino-<i>N</i>′-arylbenzamidines react with 4,5-dichloro-1,2,3-dithiazolium chloride (Appel salt) in the presence of Hünig’s base (2 equiv) to give in one step 3-aryl-4-imino-3,4-dihydroquinazoline-2-carbonitriles in 53–81% yields. Nine examples are presented along with the single-crystal X-ray structure of 4-imino-3-phenyl-3,4-dihydroquinazoline-2-carbonitrile. Furthermore, the behavior of the latter toward both acid and base hydrolysis is investigated. All new compounds are fully characterized, and a mechanistic rationale for the formation of the iminoquinazolines is provided.