Stannous chloride dihydrate → Ethyl 6-bromoquinoline-3-carboxylate

Temperature

90 °C

To a solution of 5-bromo-2-nitrobenzaldehyde (2 g, 9 mmol) in ethanol (46 mL) was added tin(II) chloride dihydrate (7.95 g, 35.2 mmol) and 3,3-diethoxypropionic acid ethyl ester (4.2 mL, 22 mmol). The reaction was heated to 90° C. for 16 hours. The reaction was then allowed to cool to room temperature and stir overnight. The reaction mixture was concentrated and the residue was dissolved in ethyl acetate. The mixture was poured into saturated aqueous sodium bicarbonate. The resulting emulsion was filtered through Celite, rinsing with ethyl acetate. The layers were separated and the aqueous was extracted with ethyl acetate. The combined organics were washed with brine, dried over magnesium sulfate, filtered, and concentrated. Purification by flash column chromatography (0-50% ethyl acetate/heptanes) gave the title compound (1.41 g, 60%) as a solid.

1. temperatureto cool to room temperature
2. concentrationThe reaction mixture was concentrated
3. dissolutionthe residue was dissolved in ethyl acetate
4. additionThe mixture was poured into saturated aqueous sodium bicarbonate
5. filtrationThe resulting emulsion was filtered through Celite
6. washrinsing with ethyl acetate
7. customThe layers were separated
8. extractionthe aqueous was extracted with ethyl acetate
9. washThe combined organics were washed with brine
10. dry with materialdried over magnesium sulfate
11. filtrationfiltered
12. concentrationconcentrated
13. customPurification by flash column chromatography (0-50% ethyl acetate/heptanes)

ORD record

ord-ed06eb1e47834546948f5d1cd4f5caa0

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08802688B2