N‑Methylimidazole Promotes the Reaction of Homophthalic Anhydride with Imines
journal contributionposted on 17.12.2015, 03:46 by Jian Liu, Zheng Wang, Aaron Levin, Thomas J. Emge, Paul R. Rablen, David M. Floyd, Spencer Knapp
The addition of N-methylimidazole (NMI) to the reaction of homophthalic anhydride with imines such as pyridine-3-carboxaldehyde-N-trifluoroethylimine (9) reduces the amount of elimination byproduct and improves the yield of the formal cycloadduct, tetrahydroisoquinolonic carboxylate 10. Carboxanilides of such compounds are of interest as potential antimalarial agents. A mechanism that rationalizes the role of NMI is proposed, and a gram-scale procedure for the synthesis and resolution of 10 is also described.