title: A practical, metal-free synthesis of 1H-indazoles.
abstract: The synthesis of 1H-indazoles is achieved from o-aminobenzoximes by the selective activation of the oxime in the presence of the amino group. The reaction occurs with a variety of substituted o-aminobenzoximes using a slight excess of methanesulfonyl chloride and triethylamine at 0-23 degrees C and is amenable to scale-up. The synthesis of 1H-indazoles under these conditions is extremely mild compared with previous synthetic approaches and affords the desired compounds in good to excellent yields.
authors.affiliation: Evans Chemical Laboratories, Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Carla M
authors.initials: CM
authors.lastname: Counceller
authors.forename: Chad C
authors.initials: CC
authors.lastname: Eichman
authors.forename: Brenda C
authors.initials: BC
authors.lastname: Wray
authors.forename: James P
authors.initials: JP
authors.lastname: Stambuli
mesh_terms: D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010091:Oximes / Q000737:chemistry*
chemical_list: D007191:Indazoles; D010091:Oximes