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.

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.

Ethyl 8''-chloro-1'-methyl-2,12''-dioxo-12''H-di-spiro-[indoline-3,2'-pyrrolidine- 3',6''-indolo[2,1-b]quinazoline]-4'-carboxyl-ate.

In the title compound, C29H23ClN4O4, the quinazoline-indole system and the indolin-2-one system are each essentially planar, with maximum deviations from their mean planes of 0.150 (2) and 0.072 (2) Å, respectively.

Ethyl 1''-benzyl-2''-oxo-2',3',5',6',7',7a'-hexa-hydro-1'H-di-spiro-[indeno-[1,2-b]quinoxaline-11,2'-pyrrolizine-3',3''-indoline]-1'-carboxyl-ate monohydrate.

In the title compound, C38H32N4O3·H2O, the quinoxaline-indene and pyrrolizine systems are essentially planar, with maximum deviations from their mean planes of 0.162 and 0.563 Å, respectively.

Ethyl 1''-benzyl-1'-methyl-2''-oxodi-spiro-[indeno-[1,2-b]quinoxaline-11,3'-pyrrolidine-2',3''-indoline]-4'-carboxyl-ate.

In the title compound, C36H30N4O3, the quinoxaline-indene system is roughly planar, with a maximum deviation from the mean plane of 0.218 Å for the C atom shared with the central pyrrolidine ring. This latter ring forms dihedral angles of 84.