3-Pentanone

Uses

3-Pentanone is primarily used as starting material in chemical synthesis. A major application is in the industrial synthesis of vitamin E. It has also been used in the synthesis of Oseltamivir (Tamiflu).

3-Pentanone itself finds some use as a specialty solvent in paint, although it is less common than butanone.

Syntheses

Ketonic decarboxylation route

3-Pentanone is produced by ketonic decarboxylation of propanoic acid using metal oxide catalysts: :2 CH3CH2CO2H → (CH3CH2)2CO + CO2 + H2O

in the laboratory, the reaction can be conducted in a tube furnace.

Carbonylation route

It can also be prepared by combining ethylene, CO, and H2. When the reaction is catalyzed by dicobalt octacarbonyl, water can be used as a source of hydrogen. A proposed intermediate is the ethylene-propionyl species [CH3C(O)Co(CO)3(ethylene)] which undergoes a migratory insertion to form [CH3COCH2CH2Co(CO)3]. The required hydrogen arises from the water shift reaction. For details, see If the water shift reaction is not operative, the reaction affords a polymer containing alternating carbon monoxide and ethylene units. Such aliphatic polyketones are more conventionally prepared using palladium catalysts.

Safety

The TLV value for 3-pentanone is 200 ppm (705 mg/m3).

References

References

1. {{GESTIS
2. {{PGCH. 0212
3. (6 December 2022). "100 Years of Vitamin E: From Discovery to Commercialization". European Journal of Organic Chemistry.
4. Hardo Siegel, Manfred Eggersdorfer "Ketones" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, 2002 by Wiley-VCH, Wienheim. {{doi. 10.1002/14356007.a15_077
5. Furniss, Brian. (1996). "Vogel's Textbook of Practical Organic Chemistry". Longman Science & Technical.
6. J. Liu. (2004). "The Complete Delineation of the Initiation, Propagation, and Termination Steps of the Carbomethoxy Cycle for the Carboalkoxylation of Ethene by Pd–Diphosphane Catalysts". [[Angew. Chem. Int. Ed.]].
7. link. (2010-01-02 , ScienceLab.com, updated 11/06/2008)