title: Efficient access to cyclic ureas via Pd-catalyzed cyclization.
abstract: [Structure: see text] An efficient regioselective method for the preparation of structurally diverse imidazopyridinones and benzoimidazolones starting from readily available and economical starting materials is described. High-yielding reductive alkylation of electron-deficient o-haloarylamines followed by treatment with inexpensive N-chlorosulfonyl isocyanate afforded primary ureas in good overall yields. A Pd-catalyzed urea cyclization reaction furnished imidazopyridinones and benzoimidazolones in excellent yields. Overall, the developed chemistry provides rapid access to pharmaceutically important heterocyclic compounds with high efficiency.
authors.affiliation: Department of Process Research, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, USA. mark_mclaughlin@merck.com
authors.forename: Mark
authors.initials: M
authors.lastname: McLaughlin
authors.forename: Michael
authors.initials: M
authors.lastname: Palucki
authors.forename: Ian W
authors.initials: IW
authors.lastname: Davies
mesh_terms: D001562:Benzimidazoles / Q000138:chemical synthesis; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D007093:Imidazoles / Q000138:chemical synthesis; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D011728:Pyridones / Q000138:chemical synthesis; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
chemical_list: D001562:Benzimidazoles; D007093:Imidazoles; D011728:Pyridones; D010165:Palladium; D014508:Urea