tert-Butyl carbazate → HCID 86660011, compound

Participants

Reaction Steps

To a round bottom flask is added 2-(5-bromo-1-tert-butyl-1H-benzimidazol-2-yl)-benzoic acid (300 mg, 0.804 mmol) in DMF (8 mL), followed by the addition of HATU (611 mg, 1.607 mmol), tert-butyl carbazate (530 mg, 4.01 mmol) and iPr2NEt (520 mg, 4.02 mmol). The reaction mixture is stirred at room temperature for 18 hours. The reaction mixture is diluted with EtOAc/water. The organic layer is separated, washed with brine, dried under anhydrous Na2SO4, filtered and concentrated. The residue is purified by silica gel flash column chromatography with 0-5% MeOH/CH2Cl2 as the eluent. The product fractions are collected and concentrated to afford N-[2-(5-bromo-1-tert-butyl-1H-benzimidazol-2-yl)-benzoyl]-hydrazinecarboxylic acid tert-butyl ester (390 mg). This material is dissolved in CH2Cl2 (3 mL), followed by the addition of trifluoroacetic acid (2 mL). The reaction mixture is stirred at room temperature for 3 hours. The reaction mixture is concentrated to afford 2-(5-bromo-1-tert-butyl-1H-benzimidazol-2-yl)-benzoic acid hydrazide (310 mg, 100%). LCMS (ESMS): m/z 387.75, 389.75 (M++1).

Provenance & Evidence