Ethyl Acetate → HCID 68285441, Verbindung

Temperatur

60 °C

To the solution of Ethyl 3,5-dibromo-4-nitrothiophene-2-carboxylate (compound 34a, 10.0 g, 27.85 mmol) in acetic acid (100 ml) was added iron powder (7.77 g, 139.27 mmol). The reaction mixture was then heated at 60° C. for 35 min under stirring. The progress of the reaction was monitored by TLC. The reaction mixture was then cooled to 25° C. Acetic acid from the reaction mixture was then evaporated under reduced pressure. The pH of the resulting reaction mass was brought to between 8 and 9 by adding to it saturated sodium bicarbonate solution. To the mixture so obtained was added ethyl acetate (150 ml), the resulting emulsion was filtered and then the organic layer was separated. The aqueous layer remaining behind was re-extracted with ethyl acetate (2×100 ml). The combined organic layers were dried over sodium sulphate and the dried organic layer was concentrated under reduced pressure to obtain a crude product, which was then purified by column chromatography over silica gel (100-200 mesh) using 2% ethyl acetate in hexanes as an eluent to obtain the title compound (6.00 g, 65.50%).

1. temperatureThe reaction mixture was then cooled to 25° C
2. customAcetic acid from the reaction mixture was then evaporated under reduced pressure
3. customThe pH of the resulting reaction mass
4. customTo the mixture so obtained
5. filtrationthe resulting emulsion was filtered
6. customthe organic layer was separated
7. extractionThe aqueous layer remaining behind was re-extracted with ethyl acetate (2×100 ml)
8. dry with materialThe combined organic layers were dried over sodium sulphate
9. concentrationthe dried organic layer was concentrated under reduced pressure
10. customto obtain a crude product, which
11. customwas then purified by column chromatography over silica gel (100-200 mesh)

ORD-Eintrag

ord-df5ea87697354d448ef9f78be7b22aac

Quelldatensatz

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09072731B2