N-bromobutanimide → Methyl 5-bromo-1H-pyrrole-3-carboxylate

A solution (70 mL) of methyl 1H-pyrrole-3-carboxylate (4.48 g) in tetrahydrofuran was cooled to −78° C., N-bromosuccinimide (6.30 g) was added, pyridine (5 drops) was added, and the mixture was left standing in a freezer (−20° C.) for 3 days. The reaction mixture was concentrated under reduced pressure, water was added to the residue and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=9:1→1:1) to give the title compound as a pale-yellow solid (yield 3.59 g, 49%).

1. waitthe mixture was left
2. concentrationThe reaction mixture was concentrated under reduced pressure, water
3. additionwas added to the residue
4. extractionthe mixture was extracted with ethyl acetate
5. washThe extract was washed with saturated brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=9:1→1:1)

ORD record

ord-805e90d0a4e04e1db7bae96962959b36

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08048909B2