Tetrahydrofuran → 2-Ethyl-8-methoxyquinoline-5-carboxylic acid

Temperature

105 °C

A mixture of 5-bromo-2-ethyl-8-methoxyquinoline (3.3 g), sodium hydroxide (3.1 g, 46% solution in water), triphenylphosphine (0.22 g), and bis(triphenylphosphine)palladium (II) chloride (0.14 g) in tetrahydrofuran (14 ml) and water (7 ml) was stirred in a pressurised reaction vessel and charged with carbon monoxide to a pressure of 160 psi. The vessel was heated to 105° C. and stirred for 24 hours. The reaction was allowed to cool and depressurised. The mixture was filtered and the solid collected washed with tetrahydrofuran (2×10 ml). The solid was dissolved in hot methanol (10 ml) and water (10 ml), and the solution filtered to remove any remaining solids. The hot solution was treated with glacial acetic acid (2 ml) and cooled in ice. The resulting precipitate was filtered off and dried over silica gel under vacuum to afford the title compound as a white solid (0.44 g).

1. stirringstirred for 24 hours
2. temperatureto cool
3. filtrationThe mixture was filtered
4. customthe solid collected
5. washwashed with tetrahydrofuran (2×10 ml)
6. dissolutionThe solid was dissolved in hot methanol (10 ml)
7. filtrationwater (10 ml), and the solution filtered
8. customto remove any remaining solids
9. additionThe hot solution was treated with glacial acetic acid (2 ml)
10. temperaturecooled in ice
11. filtrationThe resulting precipitate was filtered off
12. customdried over silica gel under vacuum

ORD record

ord-a097b292da0942bc9f65e885f774f466

Source dataset

uspto-grants-1998_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05804588