N-bromobutanimide → [3-Bromo-6-(2,4-dichloro-phenyl)-imidazo[1,2-a]pyridin-7-ylmethyl]-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of [6-(2,4-dichloro-phenyl)-imidazo[1,2-a]pyridin-7-ylmethyl]-carbamic acid tert-butyl ester (543 mg, 1.38 mmol) in DMF (5 mL) was cooled to 0° C., treated with NBS (222 mg, 1.25 mmol), and stirred at 0° C. for 1 h. The reaction mixture was diluted in AcOEt and washed with water and brine. The organic layer was dried over Na2SO4, filtered and evaporated. The residue was purified by Combi-Flash Companion™ (Isco Inc.) column chromatography (SiO2; gradient elution, [hexane/DCM 1:1]/TBME 95:5→6:4) to yield the title compound (435 mg, 0.92 mmol, 67%) as a beige foam. MS: 472 [M+1]+; HPLC: AtRet=1.93; TLC: RF 0.50 (hexane/DCM/TBME 1:1:2).

Provenance & Evidence