A Concise Synthesis of Benzo[h]- and Pyrido[3,2-h]-δ-carbolin-2,4-diones from One-Pot Reaction of β-Lactam Carbenes with Naphthyl and Quinolyl Isonitriles

Abstract

The one-pot reaction of β-lactam carbenes with 1-naphthyl or 5-quinolyl isonitriles followed by treatment with aqueous hydrochloride produced benzo[h]-δ-carbolin-2,4-diones or pyrido[3,2-h]-δ-carbolin-2,4-diones, respectively, in moderate yields. The easy availability of β-lactam carbenes and aryl isonitriles, and the simple chemical manipulations render our approach practical in the synthesis of various novel aryl fused δ-carboline derivatives, which are not easily prepared by other synthetic methods.