Hydrogen Bromide → 2-Bromo-3-tert-butoxypropanoic acid

Temperature

-7 °C

A mixture of potassium bromide (6.830 g, 57.39 mmol) and 0.75 M HBr solution (91 mL, 68.24 mmol) was cooled down to −7° C. Sodium nitrite (2.093 g, 29.47 mmol) and L-serine tert-butyl ether (2.50 g, 15.51 mmol) were added successively and the mixture was stirred 3 h at room temperature. The mixture was cooled down to 0° C., and was extracted with ethyl acetate (3×100 mL). Combined organic phases were washed with brine (2×180 mL), dried over MgSO4, filtrated and evaporated. The expected product, e.g. 2-bromo-3-tert-butoxypropanoic acid (3.481 g, quantitative yield), was isolated as a light yellow oil. This intermediate was used in the next step without further purification.

1. temperatureThe mixture was cooled down to 0° C.
2. extractionwas extracted with ethyl acetate (3×100 mL)
3. washCombined organic phases were washed with brine (2×180 mL)
4. dry with materialdried over MgSO4
5. filtrationfiltrated
6. customevaporated

ORD record

ord-4cf96b2addb54638a8ad9504d67497dd

Source dataset

uspto-grants-2007_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07312358B2