“On-Water” Palladium-Catalyzed Tandem Cyclization Reaction for the Synthesis of Biologically Relevant 4-Arylquinazolines was written by Yuan, Shuo;Yu, Bin;Liu, Hong-Min. And the article was included in Chemistry – A European Journal in 2019.Safety of 2-Amino-3,5-dibromobenzonitrile This article mentions the following:
The quinazoline scaffold is prevalent in pharmaceutically relevant mols. that show diverse biol. activities. An efficient “on-water” palladium-catalyzed tandem cyclization reaction from com. available arylboronic acids RB(OH)2 (R = Ph, 3-nitrophenyl, naphthalen-1-yl, etc.) and benzonitriles (E)-2-CN-R1C6H4N=C(R2)N(Me)2 [R1 = H, 5-Me, 4,5-(OMe)2, etc.; R2 = H, Me] that enable the rapid access to 4-arylquinazoline scaffolds I [R3 = H, 7-Me, 6,7-(OMe)2, etc.] in good to excellent yields (45 examples, up to 98% yield) was reported. This protocol has shown good functional group tolerance and broad substrate scope. The reaction was also performed on a gram scale and successfully applied to the synthesis of the highly potent and selective PI3Kδ inhibitor II, showing the practicability and synthetic utility of the protocol. In this reaction, the quinazoline scaffold I is efficiently constructed with the simultaneous formation of one C-C bond and one C-N bond. Collectively, the protocol could serve as an alternative strategy to synthesize biol. important quinazoline scaffolds. In the experiment, the researchers used many compounds, for example, 2-Amino-3,5-dibromobenzonitrile (cas: 68385-95-5Safety of 2-Amino-3,5-dibromobenzonitrile).
2-Amino-3,5-dibromobenzonitrile (cas: 68385-95-5) belongs to nitriles. The R-C-N bond angle in and nitrile is 180° which give a nitrile functional group a linear shape. Both the carbon and the nitrogen are sp hydridized which leaves them both with two p orbitals which overlap to form the two π bond in the triple bond. Nitriles are susceptible to hydrogenation over diverse metal catalysts. The reaction can afford either the primary amine (RCH2NH2) or the tertiary amine ((RCH2)3N), depending on conditions.Safety of 2-Amino-3,5-dibromobenzonitrile
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts