Methanol → Methyl 3-chloro-1H-pyrrole-2-carboxylate

Temperature

25 °C

4,4-Dichloro-5-(trichloromethyl)-3,4-dihydro-2H-pyrrole (47.4 mmol, 1.0 equiv.) was added to a solution of sodium methanolate (284.5 mmol, 6.0 equiv.) in methanol (126 ml), and the mixture was heated for 1.5 h at boiling temperature. The reaction mixture was cooled to 25° C., the solvent was concentrated under reduced pressure, the residue was taken up in diethyl ether (470 ml), and the mixture was stirred for 30 min. The resulting solid (sodium chloride) was filtered out, and the filtrate was dried over K2CO3 and concentrated under reduced pressure. The residue was taken up in DCM (600 ml), extracted with 2 N HCl (2×150 ml), dried over Na2SO4 and concentrated under reduced pressure. The crude product was used in the next step without being purified further. Yield: 83%

1. temperaturethe mixture was heated for 1.5 h
2. concentrationthe solvent was concentrated under reduced pressure
3. filtrationThe resulting solid (sodium chloride) was filtered out
4. dry with materialthe filtrate was dried over K2CO3
5. concentrationconcentrated under reduced pressure
6. extractionextracted with 2 N HCl (2×150 ml)
7. dry with materialdried over Na2SO4
8. concentrationconcentrated under reduced pressure
9. customwithout being purified further

ORD record

ord-9a0c5dd91536438b8074970b060aef88

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08492559B2