Acetyl chloride → 4-Pyridinylacetone

Temperature

50 °C

To 10 g of 4-methylpyridine and 32.75 g acetic anhydride, maintained at room temperature, was added 1 ml of acetyl chloride, dropwise over 5-10 min. The solution was then warmed to 50° C. for 6-16 hours. The black reaction mixture was then cooled to 0° C. and 100 mls of ethanol, was added dropwise. The reaction mixture was stirred for 1 hour after the addition, then refluxed for 4-12 hours. The alcohol was removed under reduced pressure and the residue taken up in 100-150 ml methylene chloride. The methylene chloride was washed 2 times with saturated 50 ml portions of sodium carbonate solution then dried over sodium sulfate and evaporated under reduced pressure. Toluene was added to the residue and the excess 4-methylpyridine removed by azeotropic distillation under reduced pressure. Yield: 4.3 gm of 4-pyridinyl-2-propanone.

1. customThe black reaction mixture
2. temperaturewas then cooled to 0° C.
3. additionafter the addition
4. temperaturerefluxed for 4-12 hours
5. customThe alcohol was removed under reduced pressure
6. washThe methylene chloride was washed 2 times with saturated 50 ml portions of sodium carbonate solution
7. dry with materialthen dried over sodium sulfate
8. customevaporated under reduced pressure
9. additionToluene was added to the residue
10. customthe excess 4-methylpyridine removed by azeotropic distillation under reduced pressure

ORD record

ord-2518bd8f12324615ab078ce146fb96d1

Source dataset

uspto-grants-1987_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04681944