Acetic Acid → Quinoline

To a mixture of 2,5-dimethylaniline (20.73 g), glycerin (54.81 g) and arsenic pentoxide hydrate (As2O5.xH2O) (Aldrich, 54% As, 35.06 g) under argon and in a 1 L 3-neck round bottom flask equipped with a mechanical stirrer is carefully added sulfuric acid (51.6 g). The resulting hot solution is then heated at 140°-150° C. for 4 hours. The reaction mixture is then cooled to room temperature and slowly basified to pH=10 by the addition of ammonium hydroxide solution (28-30%). After a period of about 10 minutes the basic solution is acidified to pH=5 by the addition of glacial acetic acid and extracted with methylene chloride (CH2Cl2) (3×500 mL). The organic layer is then washed with water (2×500 mL) and brine (2×500 mL), dried over magnesium sulfate (MgSO4), filtered, and rotary evaporated to yield crude quinoline (31 g) which is flash chromatographed on silica gel eluting with 10% ethyl acetate/hexane. Compound-containing fractions are combined and rotary evaporated to yield 5,8-dimethylquinoline.

1. customin a 1 L 3-neck round bottom flask equipped with a mechanical stirrer
2. temperatureThe resulting hot solution is then heated at 140°-150° C. for 4 hours
3. extractionextracted with methylene chloride (CH2Cl2) (3×500 mL)
4. washThe organic layer is then washed with water (2×500 mL) and brine (2×500 mL)
5. dry with materialdried over magnesium sulfate (MgSO4)
6. filtrationfiltered
7. customrotary evaporated

ORD record

ord-de0a17c0863740b6899ce57343fdf5d5

Source dataset

uspto-grants-1996_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05578607