A concise and efficient synthesis of benzimidazo[1,2-c]quinazolines through CuI-catalyzed intramolecular N-arylations

• Xinlong Pang,
• Chao Chen,
• Ming Li and
• Chanjuan Xi

Beilstein J. Org. Chem. 2015, 11, 2365–2369, doi:10.3762/bjoc.11.258

• : benzimidazo[1,2-c]quinazoline; (bromophenyl)iodonium salt; copper catalyst; o-cyanoaniline; quinazolin-4(3H)-imine; Ullmann N-arylation; Introduction Nitrogen-containing heterocycles are ubiquitous backbones in natural products, medicine and organic materials. In addition, they are also important ligands for

• diaryliodonium salts 2 to produce quinazolin-4(3H)-imine derivatives 3 with Cu(OTf)2 as the catalyst [13]. Encouraged by this finding, we initially attempted the reaction of o-cyanoaniline (1a) with di-(o-bromophenyl)iodonium salt 2. The reaction of 2 equiv of o-cyanoaniline (1a) with 2 in DCE at 110 °C for 6 h

• nitriles. The reaction of o-cyanoaniline (1a), benzonitrile (1g) and di-(o-bromophenyl)iodonium salt 2 in the presence of Cu(OTf)2 gave the desired imine 3g together with imine 3a. After isolation of 3g it was further treated with 10 mol % of CuI in DMSO for 50 min to give product 4g in quantitative yield