Acetic Acid → Methyl acetoacetate

Temperature

100 °C

Methyl acetoacetate (250 ml) and methyl propionate (400 ml) were added to approximately 10 g of this L,L-tartaric acid/sodium bromide modified Raney Nickel in methyl propionate (under an atmosphere of argon). A small amount of acetic acid (4 ml) was then added to the resulting mixture. This reaction mixture was then added to a pressure vessel and the vessel was purged with nitrogen. The reaction vessel was pressurized to 800 psi with hydrogen and heated to 100° C. with vigorous stirring. The pressure was adjusted to 1300 psi hydrogen and stirring at 100° C. was continued for 24 hours. After cooling to room temperature, releasing the pressure in the vessel, and venting with nitrogen, the contents of the reaction vessel were carefully filtered through celite. Careful fractional distillation (3 foot packed column) first removed the methyl propionate solvent (approximately 100 mm Hg, <70° C.), next provided a mixed fraction of methyl acetoacetate and methyl (R)-3-hydroxy-butyrate (108.96 g, 8 mmHg, 60°-65° C. head temperature) and a fraction of purified methyl (R)-3-hydroxybutyrate (approximately 140 g, 8 mm Hg, 60°-65° C. head temperature). The identity of all samples were verified by proton NMR.

1. additionThis reaction mixture was then added to a pressure vessel
2. customthe vessel was purged with nitrogen
3. temperatureAfter cooling to room temperature
4. filtrationthe contents of the reaction vessel were carefully filtered through celite
5. distillationCareful fractional distillation (3 foot packed column)
6. customfirst removed the methyl propionate solvent (approximately 100 mm Hg, <70° C.)

ORD record

ord-e47dd11b896c41cda5b4ea1115a3e901

Source dataset

uspto-grants-1996_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05563239