N-bromobutanimide → HCID 90167983, compound

Participants

Reaction Conditions

Reaction Steps

Ethyl 2-(5-methoxy-1H-pyrrolo[3,2-b]pyridin-3-yl)acetate (1.0 g, 4.26 mmol) was dissolved in methylene chloride (40 mL) and cooled to 0° C. with ice-water bath. NBS (760 mg, 4.26 mmol) was added in small portions over 1 hour. The reaction mixture was allowed to stir at 0° C. for two more hours. Then, to the reaction mixture were added N,N-diisopropylethylamine (1.86 mL, 8.52 mmol), di-tert-butyl carbonate (1.86 g, 8.52 mmol) and 4-dimethylaminopyridine (52 mg, 0.42 mmol). The resulting mixture was allowed to stir overnight at ambient temperature. More methylene chloride was added and washed with water and half-brine. The organic layer was separated and dried over MgSO4. The mixture was filtered and the filtrate was concentrated to dryness, and the residue was purified by silica gel chromatography (loading with toluene, eluting with EtOAc/hexanes) then RP HPLC eluting with acetonitrile/water to afford 455 mg of tert-butyl 2-bromo-3-(2-ethoxy-2-oxoethyl)-5-methoxy-1H-pyrrolo[3,2-b]pyridine-1-carboxylate and 131 mg of side product. MS (m/z): 415.0 [M+H]+; HPLC retention time 4.68 min (5-99% acetonitrile:water with 0.05% formic acid).

Provenance & Evidence