title: Parallel solid-phase synthesis of 2-imino-4-oxo-1,3,5-triazino[1,2-a]benzimidazoles via tandem aza-Wittig/heterocumulene-mediated annulation reaction.
abstract: The parallel synthesis of a large number of 2-imino-4-oxo-1,3,5-triazino[1,2-a]benzimidazole derivatives via a solid-phase 1,3,5-triazino-annulation reaction is described. The solid-phase approach involves the in situ generation of iminophosphorane derivatives derived from resin-bound 2-aminobenzimidazoles employing Mitsunobu conditions. The subsequent Aza-Wittig reaction of the iminophosphoranes with isocyanates leads to highly reactive carbodiimides, which undergo an intramolecular heterocyclization reaction to form tetrasubstituted 2-imino-4-oxo-1,3,5-triazino[1,2-a]benzimidazoles in high yields (74-94%) and good purity (>80%).
authors.affiliation: Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, California 92121, USA.
authors.forename: Cornelia E
authors.initials: CE
authors.lastname: Hoesl
authors.forename: Adel
authors.initials: A
authors.lastname: Nefzi
authors.forename: Richard A
authors.initials: RA
authors.lastname: Houghten
mesh_terms: D001562:Benzimidazoles / Q000138:chemical synthesis*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D011083:Polycyclic Compounds / Q000737:chemistry; D011126:Polypropylenes / Q000737:chemistry; D012117:Resins, Synthetic; D014227:Triazines / Q000138:chemical synthesis*
chemical_list: D001562:Benzimidazoles; D007202:Indicators and Reagents; D011083:Polycyclic Compounds; D011126:Polypropylenes; D012117:Resins, Synthetic; D014227:Triazines