Versatile Synthesis of (±)-Deoxyfebrifugine, an Antimalarial Alkaloid Analogue, and Related Compounds

The title compound was prepared by a simple route involving Eschenmoser sulfide contraction between 3-(3-bromo-2oxopropyl)quinazolin-4(3H)-one (11) and piperidine-2-thione (13) followed by chemoselective catalytic hydrogenation. This short but flexible procedure also permitted access to N-alkyl analogues, and to analogues in which the piperidine ring was replaced by other ­saturated nitrogen-containing heterocycles.