Chemoselective Reactions of Isocyanates with Secondary Amides: One-Pot Construction of 2,3-Dialkyl-Substituted Quinazolinones

• DOI: 10.1021/acs.joc.0c02929
• Publication Date: 2021-03-12T20:24:47Z
• Authors: Yi Lin; Shu-Fan He; Hui Geng; Yu-Chen Xiao; Kan-Lei Ji; Jian-Feng Zheng; Pei-Qiang Huang
• Keywords: Molecular Structure; Cyclization; Amides; 01 natural sciences; Isocyanates; Quinazolinones; 0104 chemical sciences

A facile method for the preparation of 2,3-dialkyl-substituted quinazolinones from readily available N-arylamides and commercial isocyanates was developed. This one-pot procedure involves the chemoselective activation of the secondary amide with Tf2O/2-Br-Pyr, the sequential addition of isocyanate, and cyclization. The mild reaction is general for a wide range of substrates and can be run on a gram scale.