Isobutyl chloroformate → isobutyl 6-bromo-2-methyl-1H-imidazo[4,5-b]pyridine-1-carboxylate

To a solution of 6-bromo-2-methyl-1H-imidazo[4,5-b]pyridine (3.40 g, 16.0 mmol) and diisopropylethylamine (6.5 mL, 65 mmol) in N,N-dimethylformamide (20 mL) cooled in an ice bath was added dropwise isobutyl chloroformate (2.51 mL, 19.2 mmol) and the mixture was warmed to room temperature. After 1 hour the reaction was diluted with ethyl acetate (80 mL) and washed with water (60 mL), 10% aqueous citric acid (40 mL) and brine (20 mL). The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated to a slurry. The residue was triturated diethyl ether (100 mL) and the solid isolated by filtration to give isobutyl 6-bromo-2-methyl-1H-imidazo[4,5-b]pyridine-1-carboxylate (2.3 g, 46% yield). MS (EI) for C12H14BrN3O2: 313 (MH+).

1. washwashed with water (60 mL), 10% aqueous citric acid (40 mL) and brine (20 mL)
2. dry with materialThe organic phase was dried over anhydrous sodium sulfate
3. filtrationfiltered
4. concentrationconcentrated to a slurry
5. customThe residue was triturated diethyl ether (100 mL)
6. customthe solid isolated by filtration

ORD record

ord-2f4846d5d4d64fdcb3c7c8c86601ecab

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08648066B2