Synthesis Of Dibenzo[A,F]Quinolizinium And 2-Phenyloxazolo[3,2-A]Quinolinium Perchlorates Via Acid-Catalyzed Cyclization Of L-(2-Oxo-2-Phenylethyl)Quinolin-2(1h)-Ones

摘要

Treatment of certain N-alkylated quinolm-2(lH)-ones with concentrated H2SO4 afforded oxazolo[3,2-a]quinolin-10-ylium perchlorates via a Z-form enol intermediate while others gave dibenzo[a,f]quinolizmium perchlorates via an E-form enol intermediate. We examined the structure of starting N-alkylated quinolin-2(lH)-ones and found that a methoxy group substituted at R_4 is required for the formation of tetracyclic dibenzo[a,f]quinolizinium perchlorates.