Hydrogen Bromide → Methyl 5-bromo-4-oxopentanoate

Temperature

0 °C

30 ml of trimethylsilyldiazomethane (2 M solution in diethyl ether) was added drop wise to a solution of 3-carbomethoxy propionylchloride (3.75 g, 30.5 mmol) in acetonitrile (75 ml) over a period of 10 mins at room temperature. The mixture was then stirred for 1 h. The reaction was cooled to 0° C. and 10g of 33% HBr in acetic acid was added slowly over 20 min, then the reaction was warmed to room temperature and stirred for 16 h. The solvent was removed in vacuo without heating and the residue was dissolved in ethyl acetate (100 ml), washed with 50 ml of saturated sodium bicarbonate solution and then 50 ml of brine. The organics were passed through a phase separator to remove any water and the solvent removed in vacuo. The resultant crude material was purified by kuglerhor distillation under reduced pressure (˜3 mbar, 150° C.) to give 5-bromo-4-oxo-pentanoic acid methyl ester (7g).

1. temperaturethe reaction was warmed to room temperature
2. stirringstirred for 16 h
3. customThe solvent was removed in vacuo
4. temperaturewithout heating
5. dissolutionthe residue was dissolved in ethyl acetate (100 ml)
6. washwashed with 50 ml of saturated sodium bicarbonate solution
7. customto remove any water
8. customthe solvent removed in vacuo
9. distillationThe resultant crude material was purified by kuglerhor distillation under reduced pressure (˜3 mbar, 150° C.)

ORD record

ord-d33faba6349549a29184856f7afc8660

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09051300B2