About the intermediacy of 1,2-dihydroquinazolinium salts in the Friedländer–Borsche synthesis of quinolinium salts in acidic medium
作者:José Vicente、María Teresa Chicote、Antonio Jesús Martínez-Martínez
DOI:10.1016/j.tetlet.2011.09.053
日期:2011.11
Spontaneously or under various heating conditions, 2-alkyl- or 2-aryl-(iminoalkyl)benzenamines react with ketones and triflic acid (1:1:1) to give quinolinium salts. When working under milder thermal conditions, intermediate 1,2-dihydroquinazolinium derivatives can be isolated or detected in solution but decompose upon standing or heating to give the corresponding quinolinium salts. (C) 2011 Elsevier Ltd. All rights reserved.