Tetrahedrone: Asymmetry Vol. 4. pp 1141-1152, 1993
(2R)-Alanine (4.0g, 45 mmol) was added to a saturated solution of KBr (10 ml), followed by the dropwise addition of 15ml of 47% HBr. The resulting mixture was then cooled to 0C and NaNO2 (6.21g, 90 mmol) was added over 1hr. The reaction mixture was maintained below 5C for a further 1hr and then allowed to warm to room temperature. The resulting solution was then extracted with et2O (3 X 25ml), the combined ether extracts were then dried over MgSO4 and concentrated in vacuo to give a pale yellow oil (6.54g) in 95% yield. This was distilled under reduced pressure to give pure (2R)-bromopropionic acid B.P. 68/70C/0.1 mm Hg.
A 1 molar batch could easily be done in a litre flask.
About the workup... Ether is the shyte if you live galaxies from neighbors. For SWIM (and probably most other bees), DCM is her choice for solvent. With all the in-organics remaining in this reaction.. Would the DCM not be on top? This weirds her out a bit since she's always used to the DCM being on bottom.. She wonders if DCM will cause any problems...
Regardless, she will give this a shot in the next few days and let her bees know. Rh's etNO2 synthesis from 2-Br-propionic acid looks to bee a bloody sweet rxn..
XOXO!!!
Julia