Reaction #7242

Reaction equation

H2O2

2,4,6-collidine

H2O2

acetic acid

→

2-acetoxymethyl-4,6-dimethylpyridine

Yield 24.0%

Solvents

acetic anhydride

Conditions

Workup

1. 1
   Temperaturethe solution was heated at 70° C. overnight
2. 2
   TemperatureThe reaction mixture was cooled to room temperature
3. 3
   Concentrationconcentrated under reduced pressure
4. 4
   workup.DISSOLUTIONThe residue was dissolved in CHCl3 (50 mL)
5. 5
   workup.ADDITIONtreated with solid Na2CO3 (9.9 g)
6. 6
   workup.WAITAfter 1 hour
7. 7
   Otherthe supernatant was decanted
8. 8
   Washthe residue was washed with warm CHCl3 (3×75 mL)
9. 9
   FiltrationThe combined supernatants were filtered
10. 10
    Concentrationconcentrated
11. 11
    Otherto provide 2.43 g as a yellow oil
12. 12
    Temperatureheated at 90° C. overnight
13. 13
    TemperatureThe mixture was cooled to room temperature
14. 14
    Concentrationconcentrated
15. 15
    OtherThe crude product was purified by flash chromatography (40 g silica gel, 2:1 hexanes/ethyl acetate)

Procedure

To a stirred solution of 2,4,6-collidine (3.22 g, 26.6 mmol) in glacial acetic acid (21 mL) at room temperature was added 30% H2O2 (3.0 mL) and the resultant solution was heated to 70° C. After 6 hours, the reaction mixture was cooled to room temperature, additional H2O2 (3.0 mL) was added, and the solution was heated at 70° C. overnight. The reaction mixture was cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in CHCl3 (50 mL) and treated with solid Na2CO3 (9.9 g). After 1 hour, the supernatant was decanted and the residue was washed with warm CHCl3 (3×75 mL). The combined supernatants were filtered and concentrated to provide 2.43 g as a yellow oil. The oil was dissolved in acetic anhydride (22.5 mL) and heated at 90° C. overnight. The mixture was cooled to room temperature and concentrated. The crude product was purified by flash chromatography (40 g silica gel, 2:1 hexanes/ethyl acetate) to give 1.05 g (24%) of 2-acetoxymethyl-4,6-dimethylpyridine: 1H NMR (CDCl3) □ 2.31 (s, 3H), 2.35 (s, 3H), 2.51 (s, 3H), 5.14 (s, 2H), 6.92 (s, 1H), 6.97 (s, 1H); and 0.35 g (8%) of 4-acetoxymethyl-2,5-dimethylpyridine: 1H NMR (CDCl3) □ 2.15 (s, 3H), 2.53 (s, 6H), 5.04 (s, 2H), 6.92 (s, 2H).

Source