Regioselective protection at N-2 and derivatization at C-3 of indazoles.
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.
Luo
Guanglin
G
Department of Neurosciences Chemistry, Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06443, USA. guanglin.luo@bms.com
Chen
Ling
L
Dubowchik
Gene
G
D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D007191:Indazoles