Unexpected Course of Kabachnik-Fields Reaction in the Microwave Synthesis of Quinoline-Based alpha-Aminophosphonates

The course of Kabachnik-Fields reaction in the synthesis of 3-substituted quinoline-based alpha-aminophosphonates under microwave irradiation has been investigated. Some unexpected monoester hydrogen phosphonate derivatives, obtained along with diethyl phosphonates by reaction of quinoline-3-carboxaldehyde and aniline as well as 3-aminoquinoline and benzaldehyde, respectively, with diethyl phosphite, have been analyzed and discussed.