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Updated: Jun 9, 2026

Functionalized Spirocyclic Heterocycle Synthesis and Cytotoxicity Assay
Published on: February 9, 2021
Concise Preparation of Novel Tricyclic Chemotypes: Fused Hydantoin-benzodiazepines
Steven Gunawan1, Gary S Nichol, Shashi Chappeta
1The Southwest Comprehensive Center for Drug Discovery and Development, College of Pharmacy, Department of Pharmacology/Toxicology, The University of Arizona, Tucson, AZ 85721.
Abstract:
The following article describes a concise synthesis of a collection of 4,5-dihydro-1H-benzo[e][1,4]diazepines fused to a hydantoin ring. Molecular complexity and biological relevance is high and structures are generated in a mere three steps, employing the Ugi reaction to assemble diversity reagents. The protocol represents a novel UDC (Ugi-deprotect-cyclize) strategy employed in the Ugi-5-component CO(2) mediated condensation, followed by further cyclization under basic conditions, to afford the fused hydantoin. Mechanistic caveats, dependent on aldehydes of choice will be revealed and a facile oxidation of final products to imidazolidenetriones briefly discussed.
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