88187-56-8Relevant academic research and scientific papers
The Chemistry of 2H-3,1-Benzoxazine-2,4-(1H)-dione (Isatoic Anhydride). 10. Reactions With Ester Enolates. Synthesis of 4-Hydroxy-1-methyl-3-prenyL-2(1H)-quinolinones, Crucial Intermediates in the Synthesis of Quinoline Alkaloids
Coppola, Gary M.
, p. 1217 - 1221 (2007/10/02)
N-Methylisatoic anhydride reacts with the lithium enolates of ester to produce β-ketoesters 4 in nearly quantitative yield.Thermal cyclization of these relatively unstable intermediates afford the corresponding 3-substituted-4-hydroxy-1-methyl-2(1H)quinolinones (5) in good yields.The reaction of the lithium enolate of 5-methyl-4-hexenoic acid ethylester (14) with various nuclear substituted isatoic anhydrides gives 4-hydroxy-1-methyl-3-prenyl-2(1H)-quinolinones 8,9 and 18 which are highly desirable intermediates in the synthesis of a variety of quinoline alkaloids.Treatment of 18 with DDQ furnishes oricine in 73percent yield.
