3-(Bromomethyl)-1H-indazole, N1-BOC protected → tert-butyl 3-({1-[2-(benzyloxy)-2-oxoethyl]-2,4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-3-yl}methyl)-1H-indazole-1-carboxylate

Participants

Reaction Steps

To a stirring solution of benzyl (2,4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-1-yl)acetate (3.45 g, 8.62 mM) in 25 mL DMF at 0° C. was added 1.1 equiv. of 0.5 M solution of KN(TMS)2 in toluene. The resulting solution was stirred 10–30 min, then a solution of tert-butyl 3-(bromomethyl)-1H-indazole-1-carboxylate (2.95 g, 9.48 mM) in 15 mL DMF was added. The resulting solution was stirred 2 h at RT and then quenched with 5 mL of H2O. The reaction mixture was then poured into 50 mL of EtOAc and extracted with H2O (2×50 mL). The organic layer was separated, dried (MgSO4), and the solvents removed in vacuo. The resultant material was purified by silica gel flash column chromatography using methylene chloride/EtOAc 9/1 providing 4.4 g of white solid.

Provenance & Evidence