One step synthesis of a fused four-ring heterocycle. (12th April 2018)

• Record Type: Journal Article
• Authors: Solomos, Marina A.; Bertke, Jeffery A.; Swift, Jennifer A.
• Is Part Of: New journal of chemistry. Volume 42:Number 9(2018)
• Page Start: 7125
• Page End: 7129
• Publication Date: 2018-04-12
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c8nj00629f
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : The rearrangement of a diphenylurea to a more stable quinazolinone is confirmed through X-ray diffraction and DFT calculations. Abstract : A wide range of natural biomolecules and pharmaceuticals are nitrogen rich heterocycles. Though preparation of fused multi-ring systems typically requires multiple synthetic steps, 13-imino-7, 13-dihydro-6 H -quinazolino[3, 4- a ]quinazolin-6-one (IDQQ) was serendipitously obtained in one step from commercially available phenylic precursors. Single crystal X-ray diffraction, 1 H-NMR and density functional theory calculations (DFT/B3LYP/6-31G(d, p)) were used in combination to unambiguously assign the major tautomer present in the monoclinic crystals. IDQQ appears to be the product of a thermodynamically-driven solution rearrangement of a key intermediate, 1, 3-bis( o -cyanophenyl)urea. This type of cyclization may be an efficient method for the formation of other related heterocycles.