tert-Butyl 5-fluoro-1H-indazole-1-carboxylate synthesis

Yield:1167418-10-1 75%

Reaction Conditions:

Stage #1: 1-(tert-butoxycarbonyl)-1H-indazol-5-ylboronic acidwith sodium hydroxide in methanol at 23; for 0.25 h;Inert atmosphere;
Stage #2: with silver trifluoromethanesulfonate in methanol at 0; for 0.5 h;Inert atmosphere;
Stage #3: with Selectfluor in acetone at 23; for 1 h;Inert atmosphere;Molecular sieve;regiospecific reaction;

References:

Furuya, Takeru;Ritter, Toblas [Organic Letters,2009,vol. 11,# 13,p. 2860 - 2863] Location in patent:supporting information; experimental part