Transition metal-free synthesis of quinazolinones using dimethyl sulfoxide as a synthon.

Biologically important quinazolinones have been synthesized from 2-aminobenzamides and DMSO. The key feature of the reaction is the utilization of DMSO as a methine source for intramolecular oxidative annulation. The CNS depressant drug methaqualone has also been synthesized by our methodology. The present method involves the synthesis of quinazolinones with a broad substrate scope and a good yield.

Lewis acid catalyzed unprecedented [3 + 2] cycloaddition yields 3,3'-pyrrolidinyldispirooxindoles containing four contiguous chiral stereocenters with two contiguous quaternary spirostereocenters.

A Lewis acid catalyzed domino reaction cascades through azide-alkene cycloaddition, rearrangement, aziridine ring opening, and azomethine cycloaddition with a parent dipolarophile, resulting in 3,3'-pyrrolidinyldispirooxindoles containing four contiguous chiral stereocenters with two contiguous quaternary spirostereocenters.