About the intermediacy of 1,2-dihydroquinazolinium salts in the Friedlander-Borsche synthesis of quinolinium salts in acidic medium

作者：Vicente Jose^*; Teresa Chicote Maria; Jesus Martinez Martinez Antonio

来源：Tetrahedron Letters, 2011, 52(47): 6298-6302.

DOI：10.1016/j.tetlet.2011.09.053

• Quinolinium salts
• 1,2-Dihydroquinazolinium salts
• Friedlander-Borsche reaction
• Nitrogen heterocycles
• Ketones

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.

• 出版日期2011-11-23