title: Regioselective protection at N-2 and derivatization at C-3 of indazoles.
abstract: Indazoles are regioselectively protected at N-2 by a 2-(trimethylsilyl)ethoxymethyl (SEM) group using novel conditions. The SEM group can efficiently direct regioselective C-3 lithiation, and the resulting nucleophile can react with a wide range of electrophiles to generate novel indazole derivatives. The SEM group can be removed by treatment with TBAF in THF or aqueous HCl in EtOH.
authors.affiliation: Department of Neurosciences Chemistry, Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06443, USA. guanglin.luo@bms.com
authors.forename: Guanglin
authors.initials: G
authors.lastname: Luo
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Gene
authors.initials: G
authors.lastname: Dubowchik
mesh_terms: D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D007191:Indazoles