67461-76-1Relevant academic research and scientific papers
One-step conversion of 2-Amino- N ′-arylbenzamidines into 3-aryl-4-imino-3,4-dihydroquinazoline-2-carbonitriles using 4,5-dichloro-1,2,3- dithiazolium chloride
Mirallai, Styliana I.,Manos, Manolis J.,Koutentis, Panayiotis A.
, p. 9906 - 9913 (2013/10/22)
2-Amino-N′-arylbenzamidines react with 4,5-dichloro-1,2,3- dithiazolium chloride (Appel salt) in the presence of Huenig'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.
Synthesis and X-ray characterisation of a new polycondensed heterocycle obtained by a novel Mn(III)-mediated cascade reaction of 2-cyanophenyl isothiocyanate
Calestani, Gianluca,Capella, Laura,Leardini, Rino,Minozzi, Matteo,Nanni, Daniele,Papa, Romina,Zanardi, Giuseppe
, p. 7221 - 7233 (2007/10/03)
2-Cyanophenyl isothiocyanate reacted with Mn(III) acetate in acetic acid or acetonitrile to give fair yields of a new polycondensed heterocycle arising from the joining together of two molecules of the starting isothiocyanate with loss of a CS moiety. The yields were close to 90% when the reaction was carried out in the presence of diethyl malonate. This compound was unambiguously identified by X-ray crystallography. Under the same conditions, 2-(methoxycarbonyl)phenyl isothiocyanate gave a quinazolinimine derivative instead which is likely to arise from cyclisation of an intermediate N,N′-diarylthiourea. The mechanism of formation of the former compound probably involves formation of a N,N′-bis(2-cyanophenyl)thiourea, followed by rearrangement and radical tandem ring closure of the corresponding cyclic imine derivative. This hypothesis is also supported by semiempirical calculations.
