title: An efficient intramolecular 1,3-dipolar cycloaddition involving 2-(1,2-dichlorovinyloxy)aryldiazomethanes: a one-pot synthesis of benzofuropyrazoles from salicylaldehydes.
abstract: A novel intramolecular 1,3-dipolar cycloaddition strategy for a rapid entry into benzofuropyrazoles is described. In a three-step sequence, (E)-2-(1,2-dichlorovinyloxy)aryldiazomethanes were generated in situ from the corresponding salicylaldehydes. Intramolecular cycloaddition followed by dehydrohalogenation garnered 3-chlorobenzofuropyrazoles in excellent yields. By careful choice of solvent, base, and reaction conditions, the entire sequence can be carried out in a one-pot procedure.
authors.affiliation: Johnson & Johnson Pharmaceutical Research and Development, L.L.C., 3210 Merryfield Row, San Diego, California 92121, USA.
authors.forename: Zachary S
authors.initials: ZS
authors.lastname: Sales
authors.forename: Neelakandha S
authors.initials: NS
authors.lastname: Mani
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D003978:Diazomethane / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D011720:Pyrazoles / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D011720:Pyrazoles; C013243:salicylaldehyde; D010165:Palladium; D003978:Diazomethane